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Methods and compositions to increase Agrobacterium transformation efficiency (frequencies) in both dicot and monocot host plants include adding histones to the host plant at most transiently, and using histones and L-cysteine at certain stages in monocot transformation.
1. A method for increasing Agrobacterium transformation efficiency in a host plant, said method comprising:
a. increasing histone levels in the host plant compared to normal levels of histone in the host plant by expressing an exogenous copy of a plant histone gene; and
b. transforming the host plant with Agrobacterium;
wherein the transformation efficiency of the host plant expressing the exogenous plant histone gene is increased compared to that of a plant not comprising the exogenous plant histone gene.
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6. A method of increasing Agrobacterium transformation efficiency in a host plant, the method comprising:
(a) introducing at least one copy of a polynucleotide sequence encoding a plant histone protein to the host plant;
(b) selecting a host plant expressing the polynucleotide sequence encoding a plant histone protein; and
(c) transforming the host plant expressing the polynucleotide sequence encoding a plant histone protein with a DNA molecule of interest using Agrobacterium;
wherein the transformation efficiency of the host plant expressing the polynucleotide sequence encoding the plant histone protein is increased compared to that of a plant not transformed with the polynucleotide encoding the plant histone protein.
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12. A method of increasing Agrobacterium transformation efficiency in a monocot host plant, the method comprising:
(a) introducing a nucleic acid sequence encoding a plant histone H2A into a host plant;
(b) selecting a host plant material expressing the plant histone H2A protein;
(c) infecting the host plant material with a DNA molecule of interest by infection with an Agrobacterium strain;
(d) providing at least one antioxidant in a cocultivation medium, wherein the antioxidant is L-cysteine at a concentration between about 100 mg/L and about 400 mg/L of cocultivation media; and
(e) selecting the infected material for transformants expressing the DNA molecule of interest;
wherein the transformation efficiency of the monocot host plant expressing the nucleic acid sequence encoding the plant histone H2A protein is increased compared to that of a plant not transformed with the nucleic acid encoding the plant histone H2A protein.
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This application is a continuation-in-part of U.S. Ser. No. 10/098,161 filed Mar. 14, 2002 now U.S. Pat. No. 7,122,716, which claims priority from PCT/US00/25260, filed Sep. 14, 2000 and U.S. Ser. No. 60/154,158 filed Sep. 15, 1999 now abandoned. The United States Government may have some rights to the invention disclosed due to partial support from the National Science Foundation (NSF) Grant Nos: IBN-9630779 and DBI-0110023.
The invention relates enhanced Agrobacterium-mediated transformation frequencies of plants due to addition of histones to the plant to be transformed. Methods specific for enhancing monocot transformation frequencies are also disclosed wherein both histones and L-cysteine are factors.
Agrobacterium tumefaciens is a gram negative soil bacterium that has been exploited by plant biologists to introduce foreign DNA into plants. The routine, efficient Agrobacterium-mediated transformation of dicotyledonous plants was first reported in the mid 1980's. Because monocotyledonous plants are not natural hosts for Agrobacterium tumefaciens, the development of transformation systems using this vector for monocots lagged that of dicots. Direct DNA delivery techniques including electroporation, microprojectile bombardment, and silicon carbide fiber treatment were developed for monocot transformation as alternatives to Agrobacterium-based DNA delivery. Production of fertile, transgenic maize plants was first reported in 1990 using microprojectile bombardment. Reports of fertile transgenic maize plant production using electroporation and silicon carbide fiber treatment followed a few years later.
The first well-documented report of fertile transgenic maize plants via Agrobacterium was published by Ishida et al. in 1996, followed by a second report from Negrotto et al. in 2000. Although high frequency Agrobacterium-mediated transformation was reported in those studies, and also in a few maize transformation labs in a private industry, those frequencies have not been reproduced in public maize transformation laboratories. Factors contributing to the lack of reproducibility in the public sector could include: 1) omission of critical details in protocol and media descriptions in published reports, 2) lack of access to specialized binary vectors by public researchers, and 3) reluctance or inability to transfer proprietary information from private industry to the public sector.
The significant advantages of using an Agrobacterium-based transformation system for maize (high frequency transformation, low copy, simple transgene insertion, increased stability of transgene expression, low cost relative to biolistics, and potential to introduce large DNA fragments into the plant genome) make it imperative that optimized protocols be developed, published, and made readily available to maize researchers in the public sector. Although known for this practical application, the actual mechanism of DNA transfer from bacteria to plants is not completely understood. Moreover, there are some limitations on the use of this transforming vector, e.g. difficulties in transforming monocots, and transforming frequencies may be too low to be useful. At present, even some dicots, for example, many Arabidopsis ecotypes and mutants also cannot be easily or efficiently transformed by a root transformation method, generally using Agrobacterium.
It is believed that Agrobacterium tumefaciens genetically transforms plant cells by transferring a portion of the bacterial Ti-plasmid, designated the T-DNA, to the plant, and integrating the T-DNA into the plant genome. Little is known about the T-DNA integration process, and no plant genes involved in integration have previously been identified. The DNA that is transferred from Agrobacterium to the plant cell is a segment of the Ti, or tumor inducing, plasmid called the T-DNA (transferred DNA). Virulence (vir) genes responsible for T-DNA processing and transfer are reported to lie elsewhere on the Ti plasmid. The role of vir genes in T-DNA processing, the formation of bacterial channels for export of T-DNA, and the attachment of bacteria to the plant cell are reported. In contrast, little is known about the role of plant factors in T-DNA transfer and integration.
Transformations can be transient or stable. Stable transformation is preferred because it is required to produce transgenic plants.
Many plant species are recalcitrant to stable Agrobacterium transformation. These species are, however, easily transiently transformed to express GUS activity or symptoms of viral infection following agroinoculation. Maize BMS cells are readily transiently transformed and could express and process a gus-A-intron transcript encoded by the binary vector pBISN1. Published results implied that, at least in this transformation system, T-DNA could target to maize nuclei and become converted to a double-stranded transcription-competent form. However, the lack of detectable stable transcription suggested that T-DNA integration may be deficient. Thus, making T-DNA integration more efficient and stabilizing T-DNA gene expression are important factors to improve maize transformation.
Integration of exogenous DNA is reported to be improved by delivering the DNA into plant cells with one or more Agrobacterium genes that can encode for proteins within the plant cells. This technique, referred to as "agrolistic transformation" is just an improvement over biolistic transformation by which DNA is delivered to the plants by a non-biological method such as a "gene gun" (biolistic transformation). In this improvement, genes encoding virulence proteins that normally function in Agrobacterium are transferred to the plants along with a T-DNA substrate. The substrate is then acted upon in the plant cell to make a T-DNA molecule. However, the technique described does not include the use of plant genes, or of other factors related herein. The technique was not shown to make a plant more susceptible to transformation. A goal of this method was to increase predictability of the location of integration, not its frequency. Moreover, "agrolistic transformation" is an expensive procedure requiring much infrastructure and resources; one of skill has to go through the laborious process every time to develop a transgenic plant.
The isolation of a putative plant factor has recently been reported. Ballas and Citovsky showed that a plant karyopherin α(AtKAP α) can interact with VirD2 nuclear localization sequences in a yeast two-hybrid interaction system, and is presumably involved in nuclear translocation of the T-complex. Using a similar approach, a tomato type 2C protein phosphatase, DIG3, that can interact with the VirD2 NLS was identified. Unlike AtKAP α, DIG3 plays a negative role in nuclear import. After the T-DNA/T-complex enters the nucleus, it must integrate into the plant chromosome. Plant chromosomal DNA is packaged into nucleosomes consisting primarily of histone proteins. The incoming T-DNA may have to interact with this nucleosome structure during the integration process. However, T-DNA may preferentially integrate into transcribed regions of the genome. These regions are believed to be temporarily free of histones. How exactly T-DNA integration takes place is unknown. Recent reports have implicated involvement of VirD2 protein in the T-DNA integration process.
Several ecotypes of the dicot Arabidopsis are resistant to Agrobacterium transformation. Transforming the transformation resistant rat5 mutant of Arabidopsis with a wild-type RAT5 (histone H2A) gene was reported by the inventors to complement the mutant phenotype.
In monocots, maize is the most studied model plant that has important economic value. Although genetic transformation systems for the maize have been established in private laboratories, the lack of such systems is still a key limitation for public researchers. This is because most public research groups do not have access to the resources and infrastructure necessary for maize transformation by currently available procedures. In addition, the current technology has serious limitations, including low efficiency and throughput, difficulty with inbred line transformation, unpredictable transgene copy numbers and integrity, and undesirable transgene silencing during development and over generations.
Because fertile transgenic maize (Zea mays) was first produced using the biolistic gun, maize transformation technology has served as an important tool in germplasm development and research addressing fundamental biological questions through the study of transgenic maize. Recent reports have demonstrated that Agrobacterium tumefaciens-mediated maize transformation may offer a better alternative than the biolistic gun for delivery of transgenes to maize. This gene delivery system results in a greater proportion of stable, low-copy number transgenic events than does the biolistic gun, offers the possibility of transferring larger DNA segments into recipient cells, and is highly efficient. Reproducible protocols for A. tumefaciens-mediated maize transformation have used super binary vectors, in which the A. tumefaciens strain carries extra copies of virB, virC, and virG, to infect immature zygotic embryos of the inbred line A188 or the hybrid line Hi II. Hi II immature zygotic embryos were transformed by the inventor at an average efficiency of 5.8% using the A. tumefaciens super binary vector in strain LBA4404. Because the cost of licensing this proprietary technology for use on a broader scale may be prohibitive to a public sector laboratory, the inventors implemented an A. tumefaciens standard binary (non-super binary) vector system to transform maize Hi II immature zygotic embryos. Stable transformation of maize using a standard binary vector to infect shoot meristems was reported previously, but adoption of this method was hindered by its lack of robustness. Development of a reproducible and efficient method for transforming maize using a standard binary vector will not only provide researchers with the benefits already outlined, it would also facilitate vector construction when compared with the super binary vector. Final assembly of a super binary vector system involves co-integration of the gene of interest into a large plasmid (pSB1) in A. tumefaciens strain LBA4404 via homologous recombination. In contrast, assembly of a standard binary vector does not require this additional step, making it a more efficient way to confirm the introduction of a gene of interest into an A. tumefaciens strain.
Transformation of maize (Zea mays) using an Agrobacterium tumefaciens standard binary (non-super binary) vector system was achieved by the inventors. Immature zygotic embryos of the hybrid line Hi II were infected with A. tumefaciens strain EHA101 harboring a standard binary vector and cocultivated in the presence of 400 mg/L L-cysteine. Inclusion of L-cysteine in cocultivation medium led an improvement in transient-glucuronidase expression observed in targeted cells and a significant increase in stable transformation efficiency, but was associated with a decrease in embryo response after cocultivation. The average stable transformation efficiency (no. of bialaphos-resistant events recovered per 100 embryos infected) was 5.5%. Southern-blot and progeny analyses confirmed the integration, expression, and inheritance of the bar and gus transgenes in R0, R1, and R2 generations of transgenic events. Fertile, stable transgenic maize was routinely produced using an A. tumefaciens standard binary vector system.
The level of stable transformation achieved is attributed to supplementation of cocultivation medium with 400 mg/L Cys. This antioxidant treatment also increased T-DNA delivery to embryogenic-competent scutellum cells of infected embryos. A similar increase in transient gus gene expression, followed by an increase in stable transformation efficiency, was reported in soybean cotyledonary node explants infected with A. tumefaciens and cocultivated on medium supplemented with Cys.
Contrary to expectations, the increase in stable transformation efficiency observed with the 400 mg/L Cys treatment was associated with a decrease in the proportion of embryos giving rise to embryogenic callus compared with the 0 mg/L Cys treatment. This reduction in embryo response is not related to the plant-pathogen interaction per se because noninfected embryos also exhibited reduced response on 400 mg/L Cys. It is likely that Cys concentrations as high as 400 mg/L are toxic to maize cells. A similar negative impact of 80 mg/L Cys on embryogenesis in Japonica rice explants was reported by Enriquez-Obregon et al. (1999). Comparable stable transformation rates were achieved using Cys concentrations as low as 100 mg/L, and this treatment was associated with better embryo recovery after cocultivation than that observed using the 400 mg/L Cys treatment.
A. tumefaciens-mediated maize transformation using a standard binary vector system is reproducible although variability in experimental efficiency persists. Using cocultivation medium within 7 d of preparation minimizes this variability. Average transformation efficiency is about 5.5%.
Information on plant factors and other factors affecting Agrobacterium transformation frequencies in plants is needed to improve performance of this method in both dicots and monocots.
Methods and compositions for increasing Agrobacterium transformation efficiency in a host plant include adding histones to the host plant and, for monocots, also adding L-cysteine and using a standard (a non-super, "Simple Binary Vector System") binary vector. Histones may be added either transiently or genes encoding histone may be stably incorporated into a host plant genome.
A polynucleotide sequence encoding a plant histone protein may be integrated into the host plant genome or just transiently introduced to express the polynucleotide sequence encoding a plant histone protein.
The host plant expressing the polynucleotide sequence encoding a plant histone protein to increase base levels of histone is transformed with a DNA molecule of interest by means of Agrobacterium.
There are four classes of core histones (H2A, H2B, H3 and H4). A suitable plant histone protein is a member of an H2A gene family of Arabidopsis, for example RAT5.
An aspect of the invention is a transgenic plant with at least one additional copy of a polynucleotide sequence encoding a plant histone H2A protein. The polynucleotide sequence may encode a plant histone H2A protein that is a member of an H2A gene family of Arabidopsis.
A method for increasing stable Agrobacterium transformation efficiency in host plants, includes the steps of:
(a) selecting a host plant expressing a polynucleotide sequence encoding a plant histone H2A protein, thereby increasing levels of histone in the host plant;
(b) introducing a transformation vector with a DNA molecule of interest into an Agrobacterium strain;
(c) providing at least one antioxidant in a cocultivation medium;
(d) infecting cells from the host plant with the Agrobacterium strain in the cocultivation medium;
(e) providing conditions suitable for recovery of infected cells; and
(f) selecting the infected cells for transformants expressing the DNA molecule of interest.
The host plant may be a monocot, for example, maize.
The antioxidant may be L-cysteine.
The L-cysteine concentration may be between about 100 mg/L and 400 mg/L.
Infection of cells in the cocultivation medium may be for 3 days.
An aspect of the invention is a genetic construct comprising at least one copy of a histone gene in addition to that in the host plant initially that when expressed is capable of increasing transformation frequencies in a host plant.
The histone gene may encode H2A, for example a RAT5 Arabidopsis gene.
An aspect of the invention is a host cell transformed by at least one copy of a gene involved in T-cell integration wherein the gene is capable of effecting overexpression of histone to enhance plant transformation frequencies.
A method for increasing Agrobacterium transformation frequencies in a host plant, includes the steps of:
Transformation frequencies may be measured by the number of tumors produced in the host plant or by using markers detectable if transformation has occurred.
The H2A histone may be H2A-1.
An aspect of the invention is a plant cell with an overexpression of plant histones sufficient to increase efficiency of transformation of the plant cell by Agrobacterium.
Transformation efficiency: (no. of successful events/no. of embryos infected) X 100. The number of transgenic events is a indication of stable transformation. The transformation efficiency calculation may also involve inflorescences, callus, seeds or other biological material that can be infected with Agrobacterium to produce a transformant.
H2A: A member of H2A gene family. The H2A gene members are also denoted by HTA. Arabidopsis RAT5 is one such member of H2A/HTA gene family.
Retransformation: transformation of a host plant that has at least one additional copy of a polynucleotide encoding histone H2A protein stably integrated into the host plant genome.
Infected: Agrobacterium is in the host cell.
The invention relates to methods and composition to increase Agrobacterium transformation frequencies in plants due to addition of histones directly or by incorporating into the host plant at least one plant gene involved in host T-DNA integration. This differs from some methods in prior publications because plant host genes, not bacterial Agrobacterium genes, are used to enhance transformation. In an embodiment, addition of at least one histone H2A gene encoded by the Arabidopsis RAT5 gene enhances transformation frequencies, most likely due to overexpressing of histone as compared to the host's natural expression levels. The gene can be either in transgenic plants or carried by the transforming agent, T-DNA, for practice of the invention.
To identify plant genes involved in Agrobacterium-mediated transformation, a T-DNA tagged Arabidopsis library was screened for mutants that are resistant to Agrobacterium transformation (rat mutants). An Arabidopsis T-DNA tagged mutant, rat5, was characterized that is deficient in T-DNA integration and is resistant to Agrobacterium-mediated root transformation. Both genetic and DNA blot analyses indicated that there are two copies of T-DNA integrated as a tandem repeat at a single locus in rat5. No major rearrangements are in the rat5 plant DNA immediately surrounding the T-DNA insertion site. These data strongly suggest that in rat5 the T-DNA had inserted into a gene necessary for Agrobacterium-mediated transformation. The sequence of the T-DNA left border-plant junction indicated that the T-DNA had inserted into the 3′ untranslated region of a histone H2A gene. This insertion is upstream of the consensus polyadenylation signal. By screening an Arabidopsis ecotype Ws cDNA library and sequencing 20 different histone H2A cDNA clones, and by performing a computer data base search, at least six different histone H2A genes were identified. These genes encode proteins that are greater than 90% identical at the amino acid sequence level. Thus, the histone H2A genes comprise a multi-gene family in Arabidopsis.
The gene bank accession number AB016879 contains a report of a DNA sequence of some of the clones derived from Arabidopsis thaliana chromosome 5. One of these sequences is a histone H2A gene that is identical to the RAT5 gene. However, this report neither teaches nor suggests a role for histone in improving transformation frequencies.
Overexpression of histone genes of the present invention overcomes the poor performance that limits the use of Agrobacterium as a transforming vector. Many plants can be transformed transiently by Agrobacterium so they express the transforming gene for a period of time, but are not stably transformed because of T-DNA integration problems. Therefore, transgenic plants are not produced. The gene H2A (RAT5) plays an important role in illegitimate recombination of T-DNA into the plant genome and the gene's overexpression enhances transformation.
Transient and stable GUS (β-glucuronidase) expression data and the assessment of the amount of T-DNA integrated into the genomes of wild-type and rat5 Arabidopsis plants indicated that the rat5 mutant is deficient in T-DNA integration needed for transformation. Complementing the rat5 mutation was accomplished by expressing the wild-type RAT5 histone H2A gene in the mutant plant. Surprisingly, overexpression of RAT5 in wild-type plants increased Agrobacterium transformation efficiency. Furthermore, transient expression of a RAT5 gene from the incoming T-DNA was sufficient to complement the rat5 mutant and to increase the transformation efficiency of wild-type Arabidopsis plants. Adding histone directly to the host plant enhances transformation. The present invention provides methods and compositions to increase stable transformation frequency in plants using direct involvement of a plant histone gene in T-DNA integration.
Several T-DNA tagged mutants of Arabidopsis were identified that are recalcitrant to Agrobacterium root transformation. These are called rat mutants (resistant to Agrobacterium transformation). In most of these mutants Agrobacterium transformation is blocked at an early step, either during bacterial attachment to the plant cell or prior to T-DNA nuclear import. In some of the mutants, however, the T-DNA integration step is most likely blocked. Because plant factors involved in illegitimate recombination of T-DNA into the plant genome have not previously been identified, the characterization of a T-DNA tagged Arabidopsis mutant, rat5, that is deficient in T-DNA integration, is an aspect of the present invention.
Characterization of the rat5 mutant. rat5, an Arabidopsis T-DNA tagged mutant, was previously identified as resistant to Agrobacterium root transformation. rat5 mutants are also expected in other species, e.g. maize. An in vitro root inoculation assay was performed using the wild-type Agrobacterium strain A208 (At10). After one month, the percentage of root bundles that formed tumors was calculated. Greater than 90% of the root bundles of the wild-type plants (ecotype Ws) formed large green teratomas. In contrast, fewer than 10% of the root bundles from the rat5 plants responded to infection, forming small yellow calli (
Recovery of a T-DNA-plant junction from rat5. The T-DNA integration pattern in the rat5 mutant was determined by DNA blot analyses. The results indicated that there are only two copies of the mutagenizing T-DNA integrated into the genome of the rat5 mutant. Further analysis indicated that these two T-DNA copies are present as a direct tandem repeat, as shown in
A left border (LB) T-DNA-plant junction was recovered from rat5 using a plasmid rescue technique (see Materials and Methods) and a restriction endonuclease map of this T-DNA-plant junction was constructed. An approximately 1.7 kbp EcoRI fragment that contains both plant and LB DNA was subcloned into pBluescript and subsequently sequenced at the Purdue University sequencing center. The sequence of this fragment is shown in
Complementation of the rat5 mutant with a wild-type histone H2A gene (RAT5). Two different constructions were made to perform a complementation analysis of the rat5 mutant. First, a nopaline synthase terminator (3′ NOS) was fused to the 3′ region of the 1.7 kbp junction fragment (the sequence of this 1.7 kbp fragment is shown in
Both strains At1012 and At1062 were separately used to transform rat5 plants using a germ-line transformation method (Bent et al., 1998) and transgenic rat5 plants were selected for resistance to hygromicin (20 μg/ml). Several transgenic plants (T1) were obtained. These transgenic plants were allowed to self fertilize and T1 seeds were collected. Six transgenic lines obtained by transformation with At1012 (the wild-type histone H2A with 3′ NOS) were randomly selected and their seeds were germinated in the presence of hygromycin. Tumorigenesis assays were performed as described in Nam et al. (1999) using A. tumefaciens At10 and a sterile root inoculation protocol, on at least five different plants from each of the six transgenic lines. The results indicated that in five of the six transgenic rat5 lines tested, the tumorigenesis-susceptibility phenotype was recovered (
To confirm the genetic basis of the complementation experiment, a co-segregation analysis was performed on one of the rat5 transgenic lines (rat5 At1012-6) obtained by transformation of the rat5 mutant with A. tumefaciens At1012. To examine the co-segregation of the complementing T-DNA containing the wild-type RAT5 gene with the tumorigenesis-susceptibility phenotype, seeds from a T2 plant homozygous for the rat5 mutation but heterozygous for hygromycin resistance were germinated and grown on B5 medium without selection. Roots of these plants were subsequently tested for hygromycin-resistance and susceptibility to crown gall tumorigenesis. All plants that were sensitive to hygromycin were also resistant to tumor formation in a manner similar to that of the rat5 mutant. Of the 25 hygromycin-resistant plants, at least 8 were susceptible to tumorigenesis. However, 17 hygromycin-resistant plants remained recalcitrant to Agrobacterium-mediated transformation. It is likely that these plants are heterozygous with respect to the complementing RAT5 gene and did not express this gene to a level high enough to restore susceptibility to tumorigenesis. This possibility corresponds to the finding that the rat5 mutation is dominant, and that therefore one active copy of RAT5 is not sufficient to permit Agrobacterium-mediated transformation. Taken together, the molecular and genetic data strongly indicate that in the rat5 mutant disruption of a histone H2A gene is responsible for the tumorigenesis-deficiency (rat) phenotype.
Overexpression of a histone H2A (RAT5) gene in wild-type plants improves the efficiency of Agrobacterium transformation. To determine further whether the RAT5 gene plays a direct role in Agrobacterium-mediated transformation, A. tumefaciens At 1012 was used to generate several transgenic Arabidopsis plants (ecotype Ws) containing additional copies of the RAT5 histone H2A gene. These transgenic plants were allowed to self-pollinate, T1 seeds were collected, and T2 plants were germinated in the presence of hygromycin. Tumorigenesis assays were performed as described herein at least five plants from each of four different transgenic lines. Because ecotype Ws normally is highly susceptible to Agrobacterium transformation, the tumorigenesis assay was altered to detect any subtle differences between the transformation-susceptible wild-type plant and transgenic wild-type plants overexpressing RAT5. These alterations included inoculation of root segments with a 100-fold lower concentration (2×107 cfu/ml) of bacteria than that normally used (2×109 cfu/ml), and spreading individual root segments rather than bundles of root segments on MS medium to observe tumor production. The results, shown in Table 1 and
Transient expression of histone H2A is sufficient to permit transformation of rat5 and to increase the transformation efficiency of wild-type Ws plants. Expression of the RAT5 histone H2A gene from the incoming T-DNA complement the rat5 mutant. Although transformation of this mutant with an Agrobacterium strain harboring pGPTV-HYG (lacking a histone H2A gene) resulted in only a few, slow-growing calli on hygromycin selection medium, Agrobacterium strains harboring pKM4 or pKM5 incited rapidly growing hygromycin-resistant calli on 60±21% and 54±22% of the rat5 root segment bundles, respectively. In addition, when wild-type plants were infected (at low bacterial density) with a tumorigenic Agrobacterium strain (A208) harboring pKM4, 78±8% of the root segments developed tumors, compared to 36±9% of the root segments infected with a tumorigenic bacterial strain harboring pGPTV-HYG. These transformation experiments indicate that Agrobacterium strains containing the binary vectors pKM4 or pKM5 are able to transform rat5 mutant plants at relatively high efficiency, and on wild-type plants are two-fold more tumorigenic, and are better able to incite hygromycin-resistant calli, than are Agrobacterium strains containing the "empty" binary vector pGPTV-HYG. Transiently produced histone H2A improves the stable transformation efficiency of plants by Agrobacterium.
The rat5 mutant is deficient in T-DNA integration. Agrobacterium-mediated transformation of the Arabidopsis rat5 mutant results in a high efficiency of transient transformation but a low efficiency of stable transformation, as determined by the expression of a gusA gene encoded by the T-DNA. This result suggested that rat5 is most likely deficient in T-DNA integration. To test this hypothesis directly root segments from Ws and rat5 plants were inoculated with A. tumefaciens GV3101 harboring the T-DNA binary vector pBISN1. pBISN1 contains a gusA-intron gene under the control of a "super-promoter" (Ni et al., 1995; Narasimhulu et al., 1996). Two days after cocultivation, the root segments were transferred to callus inducing medium containing timentin (100 μg/ml) to kill the bacteria. Three days after infection, a few segments were stained for GUS activity using the chromogenic dye X-gluc. Both the wild-type and the rat5 mutant showed high levels of GUS expression (approximately 90% of the root segments stained blue;
Suspension cell lines were generated from these Ws and rat5 calli and after an additional month the amount of T-DNA was assayed (using as a hybridization probe the gusA-intron gene located within the T-DNA of pBISN1) integrated into high molecular weight plant DNA from Ws and rat5 calli (Nam et al., 1997; Mysore et al., 1998).
Teratomas incited on the roots of these plants appeared similar to tumors generated on a wild-type plant. One of the transgenic plants tested did not recover the tumorigenesis-susceptibility phenotype, probably because of an inactive transgene. Transgenic T1 plants of rat5 obtained by transformation with At1062 (containing a genomic encoding RAT5 from the wild-type plant) were also tested for restoration of the tumorigenesis-susceptibility phenotype. Some of these plants were also able to recover the tumorigenesis-susceptibility phenotype, indicating complementation of the rat5 mutation. Hygromycin-resistant transgenic plants generated by transforming the rat5 mutant with pGPTV-HPT alone did not form tumors upon infection with A. tumefaciens A208.
Evidence from two independent lines of experimentation shows that the Arabidopsis histone H2A-1 is useful to improve the efficiency of Agrobacterium-mediated plant transformation in dicots and monocots.
1. Many Arabidopsis ecotypes and mutants cannot be easily transformed by a root transformation method (although they can still be transformed by the flower-dip method). The flower-dip method was used to introduce a histone H2A-1 cDNA, under the control of the CaMV 35S promoter, into a large number of recalcitrant ecotypes and mutants. A number of these transgenic lines were analyzed and evidence emerged that all ecotypes/mutants tested to date can be made competent for root transformation when they over-express the H2A-1 gene. These include mutants in the Agrobacterium attachment process (rat1 and rat3), T-DNA integration (rat17, rat18, rat20, and rat22), a chromatin mutant (HAT6), and several other mutants with as yet uncharacterized lesions (rat21 and ratJ7). Additionally, several recalcitrant ecotypes can be made more susceptible to transformation when the H2A-1 cDNA is over-expressed. These include the ecotypes Ag-0 and Dijon-G.
Other suitable mutants include (rat4, rat14, rat15, ratJ1, α7, T9 and T16) and ecotypes (Cal-0, UE-1, Ang-0, Petergof, and BI-1) when over-expressing the H2A-1 gene may also be more susceptible to Agrobacterium-mediated transformation.
2. Kan Wang at the Plant Transformation Facility, Iowa State University tested for the present invention in two different Agrobacterium strains. One contains a T-DNA binary vector with a herbicide resistance gene in the T-DNA (this is the control construction)1. The other strain contains a similar T-DAN binary vector, but in addition to the herbicide resistance gene the T-DNA contains the Arabidopsis histone H2A-1 cDNA under the control of maize adh1 promoter and intron. These strains were used in four rounds of maize transformation experiments. Usually, transformation and regeneration of maize requires an anti-oxidant (such as L-cysteine) to prevent tissue browning and necrosis as a response to the bacteria. Several thousand transformations (using the control vector without the histone gene) produced virtually no transformants. In these experiments, there were no transformants (using the control strain) without L-cysteine. With L-cysteine, about 2-3% of the infected immature embryos give transformants. Using the histone gene and L-cysteine, there was 2-3% transformation. However, with the histone gene and without L-cysteine, they obtained 2 (0.2%) transformants. Preliminary results suggest that the histone gene may sensitize the maize embryos to transformation so that a few transformants can be obtained in the absence of an anti-oxidant.
Embryos from wild-type maize plants were transformed with Agrobacterium containing a histone H2A gene and an antibiotic resistance gene in the presence of L-cysteine in the cocultivation medium. Transgenic T1 plants (founder lines) were obtained and their seeds (T2) were collected. T2 plants were selected on antibiotic resistance growth medium and based on histone H2A RNA expression data. Embryos from selected T2 plants (T2 embryos) were retransformed with Agrobacterium containing a standard binary vector and a gene of interest in the presence of L-cysteine in the cocultivation medium. An increase in the number of embryos responding indicated an increase in transformation efficiency over transformation using histone alone. Table 2 shows the overall efficiency of transformation [total putatives by event/total responding by event].
Agrobacterium-mediated transformation results in lower transgene copy number and higher gene expression compared with biolistic gun transformation of maize (
Total RNA was extracted from leaves of transgenic plants twice independently, and duplicate loadings were run per extract. Thus there were four data points for each sampled plant. Plant number 9 was incorrectly identified as transgenic; it had no expression of the H2A-1 construction and therefore was used as a background control.
Overall the H2A-1 gene was more highly expressed in A10 (H2A-containing) than in A17 (H2A lacking) lines (
Nucleic acid manipulation. Total plant genomic DNA was isolated according to the method of Dellaporta et al. (1983). Restriction endonuclease digestions, agarose gel electrophoresis, plasmid isolation, and DNA blot analysis were conducted as described (Sambrook et al., 1982).
Plasmid Rescue. Genomic DNA (5 μg) of rat5 was digested to completion with SalI. The digested DNA was extracted with phenol/chloroform and precipitated with ethanol. The DNA was self-ligated in a final volume of 500 μl in 1× ligation buffer (Promega) with 3 units of T4 DNA ligase at 16° C. for 16 hr. The ligation mixture was precipitated with ethanol, transformed into electrocompetent E. coli DH10B cells (mcrBC-; Life Technologies, Inc., Gaithersburg, Md.) by electroporation (25 μF, 200 Ω, and 2.5 kV) and plated on LB medium containing ampicillin (100 μg/ml). Ampicillin-resistant colonies were lifted onto a nylon membrane, the bacteria were lysed, and DNA was denatured in situ (Sambrook et al., 1982). A radiolabeled left border (LB) sequence (3.0 kbp EcoRI fragment of pE1461) was used as a hybridization probe to identify a plasmid containing the LB. Positive colonies were picked and plasmid DNA was isolated. By restriction fragment analysis a plasmid containing both the LB and plant junction DNA was identified. The plant junction fragment was confirmed by hybridizing the junction fragment to wild-type plant DNA. A restriction map of this plasmid, containing the LB-plant junction DNA, was made. A 1.7 kbp EcoRI fragment that contained plant DNA plus 75 base pairs of LB sequence was subcloned into pBluescript, resulting in pE1509. This fragment was subsequently sequenced at the Purdue University sequencing center.
Growth of Agrobacterium and in vitro root inoculation of Arabidopsis thaliana. These were performed as described previously by Nam et al. (1997).
Plant Growth Conditions. Seeds of various Arabidopsis thaliana ecotypes were obtained from S. Leisner and E. Ashworth (originally from the Arabidopsis Stock Centre, Nottingham, UK, and the Arabidopsis Biological Resource Center, Ohio State University, Columbus, respectively). Seeds were surface sterilized with a solution composed of 50% commercial bleach and 0.1% SDS for 10 min and then rinsed five times with sterile distilled water. The seeds were germinated in Petri dishes containing Gamborg's B5 medium (GIBCO) solidified with 0.75% bactoagar (Difco). The plates were incubated initially at 4° C. for 2 days and the fro 7 days under a 16-hr-lights/8-hr-dark photoperiod at 25° C. Seedlings were individually transferred into baby food jars containing solidified B5 medium and grown for 7 to 10 days for root culture. Alternatively, the seedlings were transferred into soil for bolt inoculation.
Growth of Agrobacterium tumefaciens. All Agrobacterium strains were grown in YEP medium (Lichtenstein and Draper, 1986) supplemented with the appropriate antibiotics (rifampicin, 10 μg/mL; kanamycin, 100 μg/mL) at 30° C. Overnight bacterial cultures were washed with 0.9% NaCl and resuspended in 0.9% NaCl a 2×109 colony-forming units per mL for in vitro root inoculation or at 2×1011 colony-forming units per mL for bolt inoculation.
In Vitro Root Inoculation and Transformation Assays Roots grown on the agar surface were excised, cut into small segments (˜0.5 cm) in a small amount of sterile water, and blotted onto sterile filter paper to remove excess water. For some experiments, excised roots were preincubated on callus-inducing medium (CIM;4.32 g/L Murashige and Skoog [MS] minimal salts [GIBCO], 0.5 g/L Mes, pH 5.7, 1 mL/L vitamin stock solution [0.5 mg/mL nicotinic acid, 0.5 mg/mL pyridoxine, and 0.5 mg/mL thyamine-HCl], 100 mg/L myoinositol, 20 g/L glucose, 0.5 mg/L 2,4-dichlorophenoxyacetic acid, 0.3 mg/L kinetin, 5 mg/L indoleacetic acid, and 0.75% bactoagar) for 1 day before cutting them into segments. Dried bundles of root segments were transferred to MS basal medium (4.32 g/L MS minimal salts, 0.5 g/L Mes, pH 5.7, 1 mL/L vitamin stock solution, 100 mg/L myoinositol, 10 g/L sucrose and 0.75% bactoagar), and 2 or 3 drops of bacterial suspension were placed on them. After 10 min, most of the bacterial solution was removed, and the bacteria and root segments were cocultivated at 25° C. for 2 days.
For transient transformation assays, the root bundles were infected with Agrobacterium strain GV3101 was used (Koncz and Schell, 1986) containing the binary vector pBISN1 (Narasimhulu et al., 1996). After various periods of time, the roots were rinsed with water, blotted on filter paper, and stained with X-gluc staining solution (50 mM NaH2HPO4, 10 mM Na2·EDTA, 300 mM mannitol, and 2 mM X-gluc, pH 7.0) for 1 day at 37° C. For quantitative measurements of β-glucuronidase (GUS) activity, the roots were ground in a microcentrifuge tube containing GUS extraction buffer (50 mM Na2HPO4, 5 mM DTT, 1 mM Na2 EDTA, 0.1% sarcosyl, and 0.1% Triton X-100, pH 7.0), and GUS specific activity was measured according to Jefferson et al. (1987).
To quantitate tumorigenesis, root bundles were infected with wild-type Agrobacterium strains. After 2 days, the root bundles were rubbed on the agar surface to remove excess bacteria and then washed with sterile water containing timentin (100 μg/mL). Individual root segments (initial assay) or small root bundles (5 to 10 root segments; modified assay) were transferred onto MS basal medium lacking hormones but containing timentin (100 μg/mL) and incubated for 4 weeks.
For transformation of root segments to kanamycin resistance, root bundles were inoculated with Agrobacterium strain GV3101 containing pBISN1. After 2 days, small root bundles (or individual root segments) were transferred onto CIM containing timentin (100 μg/mL) and kanamycin (50 μg/mL). Kanamycin-resistant calli were scored after 4 weeks of incubation at 25° C.
To determine stable GUS expression, roots were inoculated as given above and the root segments were transferred after 2 days to CIM containing timentin (100 μg/mL) without any selection. After 4 weeks, GUS activity was assayed either by staining with X-gluc or by measuring GUS specific activity by using a 4-methylumbelliferyl β-D galactoside (MUG) fluorometric assay, as described above.
To determine the kinetics of GUS expression, root bundles were infected, the root segments were transferred after 2 days to CIM containing timentin (100 μg/mL), and calli were grown on CIM without selection. Root bundles were assayed at various times, using a MUG fluorometric assay as described above, to measure GUS specific activity.
Construction of simple binary vector systems. The based constructs are monocot-optimized (e.g. utilize monocot promoters and enhancer introns) and contain proven selectable and screenable markers (e.g. bar, gusA, gfp). The gusA gene in all constructs contains an intron to prevent expression in Agrobacterium. A synthetic red-shifted, maize codon-optimized close sgfp (S65T) is (Chiu et al., 1996). The CaMV 35S promoter (double promoter region) is used to drive the screenable markers. The bar gene as a selectable marker (DeBlock et al., 1987). A maize ubiquitin promoter-intron (Ubi-1) is used to drive the bar gene expression (Christensen and Quail, 1996). the vectors are designed to reduce/eliminate the occurrence of repeated sequences within the constructs. If another promoter is needed, the "super-promoter" (Ni et al., 1995) is suitable. This promoter works well in maize does not have homology to the CaMV 35S or maize ubiquitin promoters, and is freely available for licensing from the Biotechnology Research and Development Corporation. T-DNA border sequences and multiple cloning sites are included in the base constructs
Construction of the binary vectors pKM4 and pKM5. The plasmid pE1509 containing the 1.7 kbp junction fragment cloned into pBluescript was digested with EcoRI to release the junction fragment. The 5′ overhanging ends were filled in using the Klenow fragment of DNA polymerase I and deoxynucleotide triphosphates. The T-DNA binary vector (pE 1011) pGTV-HPT (Becker et al., 1992) was digested with the enzymes SacI and SmaI, releasing the promoterless gusA gene from pGTV-HPT. The 3′ overhanging sequence of the larger fragment containing the origin of replication and the hygromycin resistance gene (hpt) were removed using the 3′-5′ exonuclease activity of Klenow DNA polymerase, and the resulting 1.7 kbp blunt end fragment was ligated to the blunt ends of the binary vector. A binary vector plasmid containing the 1.7 kbp fragment in the correct orientation (pAnos downstream of the histone H2A gene) was selected and named pKM4 (strain E 1547).
An approximately 9.0 kbp wild-type genomic SacI fragment containing the histone H2A gene (RAT5) from a lambda genomic clone was cloned into the SacI site of the plasmid pBluescript. This 9.0 kbp SacI fragment was subsequently released from pBluescript by digestion with SacI and was cloned into the SacI site of the binary vector pGTV-HPT, resulting in the plasmid pKM5 (strain El 596). Both pKM4 and pKM5 were separately transferred by triparental mating (Ditta et al., 1980) into the non-tumorigenic Agrobacterium strain GV3101, resulting in the strains A. tumefaciens At1012 and At1062, respectively.
Germ-line transformation of Arabidopsis. Germ-line transformations were performed as described in (Bent and Clough, 1998). Transgenic plants were selected on B5 medium containing hygromycin (20 μg/ml).
Agrobacterium tumefaciens Vector and Strain
A. tumefaciens strain EHA101 (Hood et al., 1986) containing the standard binary vector pTF102 (12.1 kb) was used in all experiments. The 5.9-kb T-DNA region of this construct is shown in
Plant Material
F2 immature zygotic embryos (1.5-2.0 mm) of the maize (Zea mays) Hi II hybrid genotype (Armstrong et al., 1991) were aseptically dissected from greenhouse-grown ears harvested 10 to 13 d post pollination. Ears were stored up to 3 d at 4° C. before dissection.
Infection, cocultivation, resting, and selection media were after Zhao et al. (1999) except that cocultivation medium was modified to contain Cys. All these media contained N6 salts and vitamins (Chu et al., 1975), 1.5 mg/L 2,4-dichlorophenoxyacetic acid, and 0.7 g L1 L-Pro in addition to the following ingredients: infection medium contained 68.4 g/L Suc and 36 g/L Glc (pH 5.2) and was supplemented with 100 μM AS (Sigma, St. Louis) before use; cocultivation medium contained 30 g/L Suc, 0.85 mg/L silver nitrate, 100 μM AS, and 3 g/L gelrite (pH 5.8); resting medium contained 30 g/L Suc, 0.5 g/L MES, 0.85 mg/L silver nitrate, 250 mg/L cefotaxime, and 8 g/L purified agar (pH 5.8). Selection medium was identical to resting medium with the addition of 1.5 or 3 mg/L bialaphos (Shinyo Sanyo, Tokyo). Infection medium was filter sterilized, whereas all other media were autoclaved. AS stock solutions (100 mM) were prepared by dissolving AS in 100% (v/v) dimethyl sulfoxide (DMSO) to make a 200 mM stock which was then diluted (1:1 [v/v]) with sterile water and stored in small aliquots at 20° C. Cys was added to cocultivation medium after autoclaving from freshly prepared, filter-sterilized stocks (100 mg/mL) and cocultivation medium was used within 2 to 5 d of preparation. Regeneration I medium contained Murashige and Skoog salts and vitamins (Murashige and Skoog, 1962), 60 g/L Suc, 100 mg/L myo-inositol, no hormones, and 3 g/L gelrite (pH 5.8) after Armstrong and Green (1985). Cefotaxime (250 mg/L) and bialaphos (3 mg/L) were added to this medium after autoclaving. Regeneration II medium differed from medium I in that it contained 30 g/L Suc and no bialaphos. All media was poured to 100-×25-mL plates.
Infection and Cocultivation
A. tumefaciens cultures were grown for 3 d at 19° C. on YEP medium amended with 100 mg/L spectinomycin and 50 mg/L kanamycin. One full loop (3 mm) of bacteria culture was scraped from the 3-d-old plate and suspended in 5 mL of liquid infection medium (Inf) supplemented with 100 μM AS (Inf+AS) in a 50-mL falcon tube. The tube was fixed horizontally to a bench-top shaker or a Vortex Genie platform head and shaken on low speed (approximately 75 rpm) for 4 to 5 h at room temperature. This pre-induction step was carried out for all experiments. For infection, immature zygotic embryos (1.5-2.0 mm) were dissected to bacteria-free Inf+AS medium (1.8 mL) in 2-mL eppendorf tubes (20-100 embryos per tube) and washed twice with this medium. The final wash was removed and 1 to 1.5 mL of A. tumefaciens suspension was added to the embryos. Embryo infection was accomplished by gently inverting the tube 20 times before resting it upright for 5 min with embryos submerged. Embryos were not vortexed at any time during this procedure. After infection, embryos were transferred to the surface of cocultivation medium and excess A. tumefaciens suspension was pipetted off the medium surface. Cocultivation medium contained 400 mg/L Cys unless stated otherwise. In experiments in which cocultivation medium treatments were compared, embryos were washed and infected in the same tube before being distributed between media treatments. Embryos were oriented with the embryo-axis side in contact with the medium (scutellum side up). Plates were wrapped with vent tape (Vallen Safety Supply, Irving, Tex.) and incubated in the dark at 20° C. or 23° C. for 3 d, after which embryos were transferred to 28° C. on resting medium.
Embryo response (%) was measured as the number of cocultivated immature zygotic embryos that had initiated embryogenic Type II callus formation at their scutellum base after 4 to 7 d on resting medium, compared with the total number plated. All embryos, responding or not, were transferred to selection medium.
Selection and Regeneration
After 4 to 7 d on resting medium (28° C., dark), embryos were transferred to selection medium (30 per plate) containing 1.5 mg/L bialaphos. Selection was increased to 3 mg L1 bialaphos 2 weeks later. Putatively transformed events were identified as early as 5 weeks after infection. Regeneration of R0 transgenic plants from Type II embryogenic callus was accomplished by a 2- to 3-week maturation step on Regeneration Medium I followed by germination in the light on Regeneration Medium II as described by Frame et al. (2000). Stable transformation efficiency (%) was calculated as the number of bialaphos-resistant callus events recovered per 100 embryos infected.
Acclimatization and Greenhouse Care of Transgenic Plants
Transplant and acclimatization of regenerated R0 plants was accomplished as described previously (Frame et al., 2000). Transgenic plants were grown to maturity in the greenhouse.
Statistical Analysis
Data from eight independent experiments were used to compare stable transformation efficiency from pairs of plates treated alike aside from Cys exposure during cocultivation. A sign test was used to determine whether the benefit in transgenic event recovery rate observed for the 400 mg/L Cys treatment was significantly higher than that for the 0 mg/L Cys treatment.
A Chi square test was used to determine whether the segregation ratios we observed for gus and bar gene expressing progeny plants fit the expected 1:1 ratio.
Histochemical Analysis of Transient and Stable Gus Expression
Histochemical GUS assays (Jefferson, 1987) were used to assess transient expression of the gus gene in immature zygotic embryos 1 or 2 d after the 3-d cocultivation (4 or 5 d after infection). Level of transient gus expression was assessed on a per embryo basis by estimating the number of blue foci visible on the scutellum side of each embryo. Embryos displaying blue foci only on the embryo-axis side of the explant were scored as non-expressors. The embryo was then categorized as follows: nonexpresser (no blue foci), low expresser (one-25), moderate expresser (26-100), or high expresser (>101). The number of embryos in each of these four groups was compared with the total number of embryos assessed to determine percent of total embryos in each of the expression categories. Histochemical GUS assays were also used to assess stable expression of the gus gene in bialaphos-resistant callus samples and in leaf tissue of transgenic plants in the R1 and R2 generations. Leaf segments (0.5 cm) were submerged in the substrate, vacuum infiltrated (20 inch Hg) for 10 min, and incubated at 37° C. overnight. Blue staining cells were visualized by soaking leaf tissue in 75% followed by 95% (v/v) ethanol to remove chlorophyll and leaf pieces scored as positive or negative for GUS expression.
Southern-Blot Analysis
Leaf genomic DNA was prepared from 2 to 3 g of fresh leaf tissue from putative transgenic maize plants using the cetyltrimethylammonium bromide (CTAB) method, as described by Murray and Thompson (1980). Ten micrograms of genomic DNA per sample was digested with the HindIII restriction enzyme at 37° C. overnight and separated on a 0.8% (w/v) agarose gel. DNA gel-blot analyses (Sambrook et al., 1989) were conducted on DNA samples using the 32P-labeled bar or gus fragments as shown in
Progeny Segregation Analysis for Bar Gene Expression
A glufosinate leaf-spray test (Brettschneider et al., 1997) was used to establish segregation ratios for expression of the bar gene in progeny. The herbicide Liberty (Aventis, Strasbourg, France) was dissolved in water (1.25 mL/L) along with 0.1% (v/v) Tween 20 for a final glufosinate concentration of 250 mg/L. Beginning 9 d after planting, seedlings were sprayed three times at 1- to 2-d intervals with a freshly prepared glufosinate solution and then scored for herbicide resistance (alive) or herbicide sensitivity (dead).
Retransformation Experiments
A. T2 Immature Zygotic Embryos
Final results for experiments on T2 embryos from T1 seed derived plants of one A10 and one A 11 event were presented in the last quarterly. This approach to assessing relative transformability of A10 vs A11 events was generally unsuccessful due to poor seed set on gh T2 ears.
B. A10S1 and A11S1 Callus
All the putative events picked from this callus bombardment experiment have been gus assayed and no blue was seen in any events. Recall however, that this Nobel Foundation construct, which carries the gus gene based on the map, did not produce any transients either (while the pBGF positive control bb alongside did).
These putative events were maintained on 50 or 75 mg/L hygromycin for weeks without dieing but without being convincingly real (clones being picked for section C below are as clear as a bell). BF took a subset of the best looking ones to regeneration to see if they will harden off. At present, it is likely that we recovered few to no clones from this massive amount of work. While no conclusions can be drawn about the benefit to biolistic transformation of the expression of the H2A protein in these lines, we can conclude that hygromycin selection for rapidly growing callus needs to be applied early and strongly to minimize excessive growth during subsequent selection.
C. A10 and A11 T1 Embryos
Putative clones from T1 embryos of A10 (experimental) and A11 (control) T0 plants retransformed with pTOK233 have been picked, gus assayed and some named this quarter. The number of ears per A10 or A11 event, the numbers of embryos per ear infected and the number taken to hygromycin selection after resting the embryos on 2 mg/L bialaphos to kill-off the non-segregating embryos are summarized in Table 1. We have named 33 A10 putatives and 23 A11 putatives of which 15/17 and 10/22 of those assayed to date are gus positive, respectively. Using the number of embryos responding after resting on medium containing 2 mg/L bialaphos (to kill non A10 or A11 segregating T1 embryos), the overall efficiency for A10S1 retransformation using A18S6 was 33 events/401 infected, non-dead embryos (8.2%) and for A11S1 was 23 events/753 embryos (3%) (Table 2). This suggests that, over 16 A10S1 ears and 17 A11S 1 ears, the average efficiency of transformation was higher for A10 than A11 in this screen.
The following documents are incorporated by reference to the extent they enable the present invention:
Armstrong C L, Green C E (1985) Establishment and maintenance of friable, embryogenic maize callus and the involvement of L-proline. Planta 164: 207-214
Armstrong C L, Green C E, Phillips R L (1991) Development and availability of germplasm with high type II culture formation response. Maize Genet Coop Newslett 65: 92-93
Ballas, N. & Citovsky, V. Nuclear localization signal binding protein from Arabidopsis mediates nuclear import of Agrobacterium VirD2 protein. Proc. Natl. Acad. Sci. USA 94, 10723-10728 (1997).
Bent, A. F. & Clough, S. J. in Plant Molecular Biology Manual, (eds Gelvin, S. B. & Verma, D. P. S.) vol. 3, pp. B7/1-14 (Kluwer Academic Publishers, Netherlands, 1998).
Brettschneider R, Becker D, Lorz H (1997) Efficient transformation of scutellar tissue of immature maize embryos. Theor Appl Genet 94: 737-748
Carrington J C, Freed D D (1990) Cap-independent enhancement of translation by a plant potyvirus 5′ nontranslated region. J Virol 64: 1590-1597
Chiu et al. (1996) Curr. Biol. 6: 325-330
Christensen and Quail (1996) Transgenic Res. 5: 213-218
Chu C C, Wang C C, Sun C S, Hsu C, Yin K C, Chu C Y, Bi F Y (1975) Establishment of an efficient medium for anther culture of rice through comparative experiments on the nitrogen source. Sci Sin 18: 659-668
DeBlock et al. (1987) The EMBO J. 6: 2513-2518
Dellaporta, S. L., Wood, J., & Hicks, J. B. Plant Mol. Biol. Rep. 1, 19-22 (1983).
Ditta, G., Stanfield, S., Corbin, D., & Helinski, D. R. Proc. Natl. Acad. Sci USA 77, 7347-7351 (1980).
Enriquez-Obregon G A, Prieto-Samsonov D L, de la Riva G A, Perez M, Selman-Housein G, Vazquez-Padron R I (1999) Agrobacterium-mediated Japonica rice transformation: a procedure assisted by an anti-necrotic treatment. Plant Cell Tissue Organ Cult 59: 159-168
Frame B, Zhang H, Cocciolone S, Sidorenko L, Dietrich C, Pegg S, Zhen S, Schnable P, Wang K (2000) Production of transgenic maize from bombarded Type II callus: effect of gold particle size and callus morphology on transformation efficiency. In Vitro Cell Dev Biol Plant 36: 21-29
Hajdukiewicz P, Svab Z, Maliga P (1994) The small, versatile pPZP family of Agrobacterium binary vectors for plant transformation. Plant Mol Biol 25: 989-994
Hood E E, Helmer G L, Fraley R T, Chilton M D (1986) The hypervirulence of Agrobacterium tumefaciens A281 is encoded in a region of pTiBo542 outside of T-DNA. J Bacteriol 168: 1291-1301
Jefferson R A (1987) Assaying chimeric genes in plants. The gus gene fusion system. Plant Mol Biol Rep 5: 287-405
Jefferson, R. A. m Kavanagh, T. A., Bevan, M. W. GUS fusions: Beta-glucuronidase as a sensitive and versitile gene fusion marker in higher plants. EMBO J. 6, 391-3907 (1987).
Koncz, C. and Schell, J. Mol. Gen. Genet. 204, 383-396 (1986).
Lichtenstein, C. and Draper, J. Genetic engeneering of plants. In Glover, D. M. (ed.) DNA Cloning: A Practical Approach, vol. 2, pp. 67-119 (IRL Press, Oxford, 1986).
Mason H S, DeWald D, Mullet J E (1993) Identification of a methyl jasmonate-responsive domain in the soybean vspB promoter. Plant Cell 5: 241-251
Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15: 473-497
Murray M G, Thompson W F (1980) Rapid isolation of high-molecular-weight plant DNA. Nucleic Acids Res 8: 4321-4325
Mysore, K. S., Yi, H. C. & Gelvin, S. B. Molecular cloning, characterization and mapping of histone H2A genes in Arabidopsis. In preparation.
Mysore, K. S. et al. Role of the Agrobacterium tumefaciens VirD2 protein in T-DNA transfer and integration. Mol. Plant-Microbe Interact. 11, 668-683 (1998).
Nam J. et al. Identification of T-DNA tagged Arabidopsis mutants that are resistant to transformation by Agrobacterium. Mol. Gen. Genet. 261, 429-438 (1999).
Nam, J., Matthysse, A. G. & Gelvin, S. B. Differences in susceptibility of Arabidopsis ecotypes to crown gall disease may result from a deficiency in T-DNA integration. Plant Cell 8, 873-886 (1997).
Narasimhulu, S. B., Deng, X.-B. Sarria, R. & Gelvin, S. B. Early transcription of Agrobacterium T-DNA genes in tobacco and maize. Plant Cell 8, 873-886 (1996).
Ni, M. et al. Strength and tissue specificity of chimeric promoters derived from the octopine and mannopine synthase genes. Plant J. 7, 661-676 (1995).
Sambrook, M. A., Fritsch, E. F., & Maniatis, T. (1982) in Molecular cloning: A laboratory manual. 1 st ed. (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.)
Sambrook J, Fritsch E F, eds (1989) Molecular Cloning: A Laboratory Manual, Ed 2. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
Vancanneyt G, Schmidt R, O'Connor-Sanchez A, Willmitzer L, Rocha-Sosa M (1990) Construction of an intron-containing marker gene: splicing of the intron in transgenic plants and its use in monitoring early events in Agrobacterium-mediated plant transformation. Mol Gen Genet 220: 245-250
Zhao Z Y, Gu W, Cai T, Pierce D A, inventors. Nov. 9, 1999. Methods for Agrobacterium-mediated transformation. U.S. Pat. No. 5,981,840
Zhao Z Y, Gu W, Cai T, Tagliani L A, Hondred D A, Bond D, Krell S, Rudert M L, Bruce W B, Pierce D A (1998) Molecular analysis of T0 plants transformed by Agrobacterium and comparison of Agrobacterium-mediated transformation with bombardment transformation in maize. Maize Genet Coop Newslett 72: 34-37.
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Chicken Paella
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email@example.com:blogger.com,1999:blog-5698599151422542939.post-82661286573585679742014-10-27T07:06:55.086-04:002014-10-27T07:06:55.086-04:00i didn't find any link in the bottom, the cont...i didn't find any link in the bottom, the content is less yet powerful.Epicresearch.cohttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-33774296202296445442014-10-27T07:05:24.815-04:002014-10-27T07:05:24.815-04:00Smart money investment is an essential for current...Smart money investment is an essential for current scenario for every individual who want to improve their lifestyle as regards Epic research.Nidhi Singhhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-59309126372250887012014-10-25T13:53:48.107-04:002014-10-25T13:53:48.107-04:00Brilliant. The best one ...never go full nietche Brilliant. The best one ...never go full nietche email@example.com:blogger.com,1999:blog-5698599151422542939.post-61558670415723324242014-10-24T14:55:58.000-04:002014-10-24T14:55:58.000-04:00I see what you did there.I see what you did there.Larry D'Annahttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-9489325742670493412014-10-08T08:04:18.081-04:002014-10-08T08:04:18.081-04:00Well an another investor may have had the opposite...Well an another investor may have had the opposite, pleasant experience of receiving a raise or an unexpected inheritance as informed by Epic research.Nidhi Singhhttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-19322160129679948372014-10-03T15:38:19.631-04:002014-10-03T15:38:19.631-04:00Brilliant.Brilliant.Kevin Erdmannhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-37850418398882303932014-09-16T10:43:40.721-04:002014-09-16T10:43:40.721-04:00C.R.E.A.M. get the money (dolla dolla bill y'a...C.R.E.A.M. get the money (dolla dolla bill y'all)Samuel Wilsonhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-78061879882641445012014-09-16T10:29:08.356-04:002014-09-16T10:29:08.356-04:00straight cash homiestraight cash homieAngushttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-61321687728081669572014-09-11T04:03:21.957-04:002014-09-11T04:03:21.957-04:00Many people don't realize how important is to cont...Many people don't realize how important is to control their finances. Some don't understand how they became bankrupts and what to do if it happened. If I have some financial problems I always turn to internet consumer loans online. These loans are always good help if you don't have money to pay for something. But be careful before taking loan. Always try to find a trusted company and not to use credit cards. email@example.com:blogger.com,1999:blog-5698599151422542939.post-44414055342166435432014-09-10T16:29:27.806-04:002014-09-10T16:29:27.806-04:00Looking forward to the day Americans start having ...Looking forward to the day Americans start having reasonable/realistic attitudes towards sex.

Not holding my email@example.com:blogger.com,1999:blog-5698599151422542939.post-24209464863921945442014-09-09T08:23:57.459-04:002014-09-09T08:23:57.459-04:00Frankly speaking I didn't got the stuff what y...Frankly speaking I didn't got the stuff what you posted in the blog, what it is all about ?Epic researchhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-18141349410130091742014-09-07T13:48:03.001-04:002014-09-07T13:48:03.001-04:00Hard choice for me. Frank Zappa was my initial ans...Hard choice for me. Frank Zappa was my initial answer, but he had a pretty fulfilling musical career already and lots of stuff unreleased still in the vaults. It would've been interesting to see how his neo-classical/fusion style would be informed by the late 90's and 2000's.

Dwayne Goettel is one I can't really argue with. He was easily the most creative member of Skuppy as the albums made before and after his presence indicate. An extension of the Too Dark Park/Last Rights/Process sound would've been amazing. Stephenhttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-3514824382110670542014-09-07T13:17:07.054-04:002014-09-07T13:17:07.054-04:00My actual answer was Freddie Mercury - a singer-so...My actual answer was Freddie Mercury - a singer-songwriter-pianist-showman. The Ox was my backup.Steven Horwitzhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-19345940554468913642014-08-20T07:24:27.347-04:002014-08-20T07:24:27.347-04:00Epic research is one of the pioneers in the Indian...Epic research is one of the pioneers in the Indian financial tips industry to adopt best practices in research and delivery of its services to clients in India and globally. Nidhi Singhhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-90755872783505784862014-08-19T12:34:09.265-04:002014-08-19T12:34:09.265-04:00I wonder where I can get money for an operation or...I wonder where I can get money for an operation or buying a house in case my credit history is far from being perfect? Banks would refuse me, and the only option I know is bad credit loans. So if people had a choice, there would be some point to talk about it. But often situations arise when we are in need of some temporary cash urgently but do not have adequate funds.Rick Losthttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-63522279821188921572014-08-19T08:30:42.313-04:002014-08-19T08:30:42.313-04:00In case of intra-day trading, apart from identifyi...In case of intra-day trading, apart from identifying volatile stocks, fixing a strict stop-loss is equally important.
Epic researchhttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-80500083835968142862014-08-19T08:15:30.784-04:002014-08-19T08:15:30.784-04:00Well more often than not they end up losing money ...Well more often than not they end up losing money because of the short time span that they have at their disposal to predict and time the markets.
Epic researchhttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-81969348090802062272014-08-19T06:30:45.507-04:002014-08-19T06:30:45.507-04:00As I can understand the conditions for workers are...As I can understand the conditions for workers are very bad and the salary is quite low, despite the high quality and popularity of such carpets. I think the reform must be done. I see a lot of immigrants who work for nothing. Just as an everyday solution for money problems I can recommend to get  Canadian loans online. For foreign workers is a good way to get quick extra money, because there's no need to show the credit history. You just need to fill in the application form on-line.Sandra Leehttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-27791150746441036102014-08-07T13:47:38.666-04:002014-08-07T13:47:38.666-04:00Yeah, but the costs of prohibition are far higher ...Yeah, but the costs of prohibition are far higher for marijuana. I don't think many libertarians are in favor of any sort of drug prohibition, it's just that marijuana legalization would be both highly beneficial and relatively easy to do. Once marijuana is legal and nothing bad happens, people will be more open to legalizing, or at least decriminializing the other drugs.azmytheconomicshttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-83577680990323102752014-08-03T20:56:54.918-04:002014-08-03T20:56:54.918-04:00Cost of building ~360.000 pounds Cost of staffing ...Cost of building ~360.000 pounds
Cost of staffing ~20,000 pounds
-> needs one thousand cars per day to break even
~ 1 car every 80 seconds
he will lose money unless it is a very busy road
--people have a choice
-euvoluntaryMichael Allen Gillespiehttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-82519046731117961902014-07-31T16:01:03.794-04:002014-07-31T16:01:03.794-04:00Agreed. "it's not primary thing determi...Agreed.

"it's not primary thing determining effectiveness."

The role of luck is easily understated. Especially here.Samuel Wilsonhttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-18384456576647268822014-07-31T15:05:35.593-04:002014-07-31T15:05:35.593-04:00Maybe this is a sign of my cynicism, but I view th...Maybe this is a sign of my cynicism, but I view the "grim dedication" stuff as mostly either kayfabe or irrelevant.

Also, note that it's not that fun-loving buffoonery doesn't hurt one's effectiveness. It does, but it's not primary thing determining effectiveness.

You can also think of a certain disregard for the law as one of the perquisites of office. Let's say you are significantly more effective than any competitor. Your money compensation can't go up, but you can be more buffoonish as a compensating differential.azmytheconomicshttp://firstname.lastname@example.com:blogger.com,1999:blog-5698599151422542939.post-49022261538699528562014-07-31T14:58:08.068-04:002014-07-31T14:58:08.068-04:00I wouldn't say it's not ethically possible...I wouldn't say it's not ethically possible to hire an exceptionally poor person to do anything. If it's a value proposition that looks like it was designed to rub "markets in everything" in the faces of idealists such as myself, then maybe someone is being used as ideological cannon fodder. If it's employment that itself negates desperately poor status, then you have an ethical virtue. Since success is more who you know than what you know, perhaps an even more ethically virtuous path is inviting a desperately poor person into your "network," and maybe even pull strings for them next time you're working a room, as you might for a favorite nephew...Lorrainehttp://email@example.com:blogger.com,1999:blog-5698599151422542939.post-23397915707240250842014-07-31T14:45:48.818-04:002014-07-31T14:45:48.818-04:00If the distasteful tweets are a result of the Twit...If the distasteful tweets are a result of the Twitter account being compromised, I would think there are very real euvoluntary issues at play. I don't know what the euvoluntary implications are of undeserved hits against reputation. Given a "reputation economy" or even "reputation currency," it would be a far worse crime than identity theft, but also probably a lower-hanging fruit for perpetrators.

Not related to euvoluntarism, but I absolutely cringe whenever some news broadcast yet again shows some variant on the "person got laid off, decided to forego the 'corporate world' or whatever, and go into the cupcake business." Why always cupcakes? It's becoming more than a little cliché. Sure desserts are one merchandise that practically "sells itself," but this isn't exactly a staple food (unless maybe we're talking sugar-free protein fortified cupcakes). My point is, if they're trying (as seems to be the case) to make a case for self-employment being the fix for the problems of employment, let alone a wholesale replacement for employment across the population (a dubious proposition, IMHO), they should have a more diverse portfolio of startups in their cache of feel-good news stories, and maybe include some heavy-lifting sectors like energy or construction or non-boutique food or something.

Lorrainehttp://firstname.lastname@example.com


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Growth Strategies
To Be a Successful Service Company, Shift Your Focus to Tech
This pivot from service to tech is a strategy more firms are adopting. And those that do will experience a competitive edge.
Growth Strategies Articles and Videos
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Is your company an assemblage of the drowsy. Encourage members of your team to catch up on rest in these ways.
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Be prepared for the annual race to send packages to all corners by doing the proper advance legwork.
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Will Big Companies Follow Microsoft's Lead and Make It Harder for Startups to Win?
A large player starts to get wise to the ways of newcomers that are experimenting rapidly.
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The Danger of Continuous Partial Attention
Your distractions are keeping you from being alert, attentive and focused and can hamper your post-event follow up not to mention your day to day activities.
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Your Business, Only Leaner: Are You Over or Underspending? How to Tell.
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Any time you match sellers with buyers, you have to ensure both sides of the deal are growing proportionately.
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Always Deliver More, in Business and Life, With These 3 Principles
Make 'more' your mantra to wow your clients and delight your customers.
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Why You Need Backup Employees
You should have a replacement waiting in the wings, even for the star employee you love.
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How to Turn an Underperformer Into an Ideal Employee
A good leader will address problematic behaviors to give the person a chance to improve.
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Starting this week, the video-sharing platform is allowing its creators to select a URL that better reflects their brand and content.
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Struggling to grow your company's sales ? Here are four tips on how to turn your sales team around.
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text:
I said flashes. I know Atlus isn't at Squeenix levels yet. :P It is kind of extreme. Point is I'd rather not see them get there.. anytime soon :P
I too liked P3's AI, although Mitsuru DID cast Tentarafoo too much. Plus I hear nightmarish stories of her being charmed and casting Diarahan on the final boss. Yikes.


text:
'Maintaining good-to-excellent photo quality'
'Sharp lens, Good quality at high ISOs'
'Solid image quality in a pocketable body'
'Compact, Easy to use, First rate optics, Excellent image quality'
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'Wide maximum aperture, Built-in Wi-Fi'
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'Fast, bright, versatile lens'
'Produce images better than any small sensor camera'
'20x zoom, RAW capture, Compact size, Attractive shape and size'
'Versatile pocket camera'
'Good colour reproduction, Wi-Fi connectivity'
'EXR mode works well in a variety of conditions'
'Wireless smartphone/tablet sync and pet detection'
'Sprightly performance, high quality photos'
'Good overall resolution and sufficient zoom without paying for an SLR'
'A small camera that's easy to use but functionally limited'
'Simple yet stylish'
'Subtle design, Speedy autofocusing, Easy to use'
'Intelligent Auto mode'
'Rugged build quality, handy tracking focus mode'
'Good camera with awesome WiFi'
'Pictures are sharp, colourful and well exposed'
'Good image quality and colour'
'Lovely, high-class body'
'Free iOS and Android companion apps'
'Sharp 20x zoom lens, Compact body'
'Enhanced GPS functionality, intelligent digital zoom'
'Plenty of useful shooting features'
'Capture wonderfully-detailed and richly-coloured images'
'Full High Definition Movies, GPS Tracking'
'Image clarity, Video output'
'Able to take full-resolution stills during video capture'
'1080p HD video mode with optical zoom'
'GPS and simultaneous photo and video capture'
'Zoom range, High-speed shooting, Touch screen AF'
'Small, lightweight pocket camera'
'Compact design makes it truly pocketable'
'Response times are pretty good when not using a flash'
'Produces sharp enough images'
'Slim, Good macro mode'
'Good amount of zoom'
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'Battery life is very good versus comparably priced models'
'Full HD Movies, Stereo sound'
'Capture beautiful pictures even in dark or dimly lit surroundings'
'Delivers fast shooting performance and very good photo quality'
'Long 10x zoom lens'
'Compact body has good handling'
'Good amount of zoom in compact body'
'Poor LCD viewing angle and limited battery life are issues that can't be ignored'
'Small camera, but it has a big lens that makes it a versatile camera.'
'Good overall image and video quality, particularly for web use or small prints'
'Its picture quality is good, its ease of use is high and it's a great little compact camera to carry with you in your pocket'
'Extra Zoom, Full High Definition Movies'
'Can produce some very nice photos and movie clips'
'Fast focus and continuous shooting'
'Good-looking, slim, metal-bodied compact'
'Great overall image quality'
'Bright, ultra-wide-angle lens'
'Capable of recording videos in Full HD at 1080p'
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text:
72 search results for Krysten Ritter
Alexandra Daddario, Krysten Ritter among candidates testing for Marvel's 'Jessica Jones'
Type: Post | Date: Wednesday, Nov 19, 2014Plus it looks like some serious candidates have emerged for Luke Cage as well
New 'Veronica Mars' photos show Kristen Bell, Tina Majorino, Krysten Ritter and more
Type: Article | Date: Monday, Mar 3, 2014A long time ago, they used to be friends, and their reunion approaches
Archie Panjabi is leaving 'The Good Wife' to star in her own TV show
Type: Post | Date: Wednesday, Oct 15, 2014NBC scraps 'Mission Control' starring Krysten Ritter
On the set of the 'Veronica Mars' movie
Type: Post | Date: Friday, Feb 21, 2014Hanging out with the improbable revival of the early '00s detective show
Big Eyes
Type: Event | Date: Thursday, Dec 25, 2014Tim Burton directs this true story staring Christoph Waltz and Amy Adams.
10 Stories You Might Have Missed: 'Game of Thrones' plans unprecedented flashbacks
Type: Gallery | Date: Saturday, Oct 18, 2014"Game of Thrones" fans have come to expect plenty of twists and tur...
Veronica Mars - DVD
Type: Event | Date: Tuesday, May 6, 2014Veronica Mars finds herself being pulled back into a life she thought she had left behind
Veronica Mars (Blu-ray + UltraViolet)
Type: Event | Date: Tuesday, May 6, 2014Kristen Bell finds herself being pulled back into a life she thought she had left behind
Big Eyes - Trailer #1
Type: Video | Date: Tuesday, Sep 23, 2014A drama centered on the awakening of the painter Margaret Keane, her phenomenal success in the 1950s, and the subsequent legal difficulties she had with her husband, who claimed credit for her works in the 1960s.
Listen Up Philip - Trailer #1
Type: Video | Date: Tuesday, Sep 16, 2014Anger rages in Philip as he awaits the publication of his second novel.


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Written by Dentistry Today Monday, 16 July 2012 13:48
Eschenburg, June xx, 2012 – Kettenbach GmbH & Co. KG (www.kettenbach.com) has developed an entirely new material for one step impression techniques: Vinylsiloxanether (VSXE). Introduced on the market under its product line "Identium", it combines the advantages of the most tried and tested materials, A-silicone and polyether. Test results reporting excellent flow and hydrophilic properties were published in the CLINICIANS REPORT® volume 5, Issue 3.
Read more: Kettenbach's Identium impression material receives excellent report


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Advocating for Equality and Justice in New York
May 10, 2012 by Guest contributor
The following post comes from Pete Webb with the HRC Board of Governors:
HRC members from NYC, Long Island and Upstate New York joined hundreds of advocates at the May 8 lobby day in Albany. HRC members joined other advocates in meetings with Sen Krueger, Sen Savino, Sen Skelos, and other officials.
Our primary focus was to thank our friends that supported marriage equality and encourage all elected officials to continue the work for LGBT equality - including support of homeless youth programs and transgender rights.
The Gender Expression Non-Discrimination Act (GENDA) will prohibit discrimination against transgender people in employment, housing, credit, education and public accommodations, and also extend hate crimes protections.
Seventy-eight percent of New York State voters support passage of such a law, including 74 percent upstate, 79 percent in New York City, 82 percent in downstate suburbs, 86 percent of Democrats, 67 percent of Republicans and 78 percent of Independents.
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Contact us : BBM: 330E61A0..Tel:1876-395-8008 or
firstname.lastname@example.com for information on how to get your information posted on our site.
Lyrics ~ Videos ~ News ~ Whats New ~ Articles ~ Booking ~ Frontpage
by DRW
Uncle Demon and Daddy Devil by Tommy Lee and Vybz Kartel getting Criticism from all corners of the the dancehall and reggae music industries.
Over the last few days, Bounty Killer took to social media outlet, Twitter to voice his frustrations against Tommy Lee and other Dancehall artistes who use demonic lyrics in their songs. The Alliance leader first tweeted a link which tied in the 'Sparta' concept to homosexuality, sparking more controversy and speculation regarding Tommy Lee's 'Gaza Sparta' persona. Then the legendary Dancehall superstar issued a damning statement reprimanding Tommy Lee and other artistes who reference demonic spirits in their music.
In part the statement read, "Tired a dem now yow every man know a me say youths fi run the place, but nuh come chat nuh f****y bout freak and devil or demon, ago kill off some a dem, so when a man ago sing certain things him nuh think say nobody was gonna have a problem wid him argument dem, a when since u can just come inna dancehall and a bring een demon ppl freely so? how long we have we dancehall nice and pure mad mi mad to bloodc****, some a dem too brite and no big man inna dancehall naah stand up and tell dem say dat nuh accepted, ppl mi fight fi dancehall wid mi life and say f**k career dem naah mash it up enuh!"
Bounty's continuous rants coupled with speculation that clash could occur at STING 2012 between himself and Tommy Lee prompted the latter artiste to respond.
According to Tommy Lee, he respects Bounty Killer too much to engage in any sort of feud with him.
Comments for Tommy Lee and Vybz Kartel's Demon songs getting Criticism from Bounty Killer and Skatta Burrell
Click here to add your own comments
Join in and write your own page! It's easy to do. How? Simply click here to return to Comments.
Dancehall artiste Flippa Moggela Could Get 25 To Life in Prison
The ten richest Jamaican Dancehall & Reggae Music Entertainers
Chronixx Received a Personal Congratulation from Mick Jagger
Mr. Vegas Replies to I-Octane, says "badmind" not in his DNA !
Lyrics ~ Videos ~ News ~ Whats New ~ Articles ~ Booking ~ Frontpage
Contact us : BBM: 330E61A0..Tel:1876-837-7665..1876-395-8008 or
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Recording artiste Linguiss Released the Truth About Ebola [LISTEN HERE]
Roots Festival: Interview with Jamaican reggae singer, Scratchylus
Nov 24, 14 11:17 PM
1. Bugle - Who Am I To Love 2. Anthony Malvo and DJ Chris Pick Up The Pieces 3. Chester Miller - Gift Of Life 4. Delly Ranx - Highest Grade 5. Tony Tuff
Nov 22, 14 09:23 PM
Dancehall artiste Laden who made his debut in 2009 say 2015 will be his next blow up year. The artiste who has remained relatively quiet since his rising
Nov 21, 14 11:28 PM
slim thing mix with a fattie
Nov 21, 14 07:24 PM
The Birmingham Reggae Unity Bash will be held on December 27th, 2014 at2nd Ave North Birmingham Alabama. The concert will feature reggae singer Khalilah
Nov 21, 14 01:12 PM
Evolution Project is a collaborative musical journey that delves deeply into Senegal's rich contemporary music scene and creates a creative artistic space
Aidonia To Unveil '1V' Collection at Take Style Out
Artiste of the Month
MIA Production warns Public against an impostor pretending to be Gyptian
Irie FM Elise Kelly Interview With Jah Cure On Easy Skanking
Reggae Star Vision Debuts the Nostalgic "We Jammin" Video
Natural Black Releases New Video "I'm On My Way".
J Capri - Boom And Bend Over (Official Music Video)
LL Cool J Ft. Mavado – The Hustler (Official Video)
Nesbeth - Taste Victory [Official Video 2014]
ZAGGA - My Destination (Official Video)
Etana Trigger Official Music Video
One Zeal - Welcome to Jozi Official Music Video
Assassin aka Agent Sasco - Sekkle An Cease Official music video
Romain Virgo - Stay With Me (Official Music Video)
Demarco Bad Gyal Anthem Official Music Video
Ce'Cile ~ No Gal (Official Music Video)
Tommy Lee Sparta - Pat It Up Official Music Video
Shuga - Give My Soul To Jah (Official HD Video)
Vershon "Key Fi Mi Life" Official Music video.
Vybz Kartel Miami Vice Episode Official Music Video
RDX Summer Time Official Music Video
Sah Jam you make me feel official video
Bugle ft Julian Marley "Move Dem" Official music video
Little presence of Jamaican musicians on Billboard Reggae charts
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2-Day Kangaroo Island Tour from Adelaide
Read what other Viator.com travelers think about the 2-Day Kangaroo Island Tour from Adelaide. What they loved, what they liked and what they think could be improved, it's all here to help you make the most of your next trip.
Click here for tour details, schedule and pricing
Great Trip, Our guide Les was excellent, an animal lover's dream holiday.
Excellent trip, Les was fantastic as a guide , lots packed in and an animal lover's dream
At the beginning there was a mix up with the pick-up point in Adelaide causing some fraught moments and a rather disgruntled, though very polite, driver.
Thereafter the tour was the highlight of our trip to Australia, with many sights, animals and good food and accommodation. Overall, excellent.
Great way to see Australia untouched by commercial. =)
We really enjoyed this excursion. It was a rather early start but that meant we had a full day on the island even after a long drive and ferry crossing. The bus driver and guide was excellent. The tour made the most of the features of the island and it was particularly exciting to see the wild life. We were glad we flew home and arrived in Adelaide a bit early than the bus as a result.
Sea link,the local operator,is very
organized,very good in over all.
I loved everthing in this tour include
the tour guide,Kalen.I plan to visit
this island again someday,many things to do and see.
Very well organized, beautiful hotel.
Kangaroo Island is a fantastic island, and the best destination from South Australia
Richard L
Pleasant trip, packed itinerary, nice food and accommodation. The initial pick up and return drop off trips might be a bit long but you get to view a Doco about the Island on board the ferry too!
We enjoyed our 2 day tour on Kangaroo Island. Warning for anyone that gets motion sickness the ferry moves against the swell so a bit of a rough ride. There was a little confusion about which bus was ours it could have been prevented if they were colour coded so we could find it easily. Enjoyed the close encounter of the sea lions, the bird of prey demonstration, the opportunity to feed kangaroos but the two highlights were the pelican feeding and seeing the koalas at the Hanson Bay Wildlife Sanctuary.
It was truly amazing. Spent two weeks in the Adelaide area and, beyond a doubt, this tour was the best experience of our trip. From spectacular scenery to feeding kangaroo and petting a koala. Took hundreds of photos and couldn't wait to show them off. They are long days with five stops the first and six the second but we'll remember it forever. The hotel in Kingscote was very nice. Food stops were wonderful. Driver was personable and knowledgeable. We NEVER would have found all the wonderful places we visited.
The tour was excellent from start to finish and was a wonderful overview of a superb Island. The very best thing was our driver, Les, he was quite simply OUTSTANDING and you should cherish him!! On all our travels we have never had a more informed, friendly, humerous and talented guide. The hotel we stayed at also added to the great value for money of a well conceived tour. Congratulations Viator!
What a FANTASTIC time! This had to definitely be the highlight of our tour in Australia. We had Liz as a tour guide and we couldn't have asked for a better person! He was funny, nice, thoughtful, and knew the land like the back of his hand! The only thing that I really wish wasn't part of this tour was the Parndana Wildlife Park. The birds had no room to fly, the place was in terrible condition, the koalas only had a stump of a tree and had people poking and prodding them all day long. What a prison for these animals. It was a really sad place to visit and almost all of the other guests on the tour thought the same thing. If you love animals, DO NOT go to this place! Why not have the tour see the penguins instead?? I was really disappointed that this was not part of the tour. Other than that, it was great! I LOVED the sanctuary itself!
Would suggest they cut down on the Nature/Animal Reserves and concentrate more on the positives of the Island.
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