there is still limited molecular genetics information on different species of nepenthes pitcher plants.the lack of transcriptomes from this genus hinders further studies on the molecular mechanism and evolution of their carnivory habit.this dataset provides the first full - length transcriptome sequences from pitcher tissues of three well - studied nepenthes species , which is important for guiding functional genomics and proteomics studies.this will further improve our understanding on the nepenthaceae evolutionary history and contribute to gene mining for useful digestive enzymes for industrial applications . the lack of transcriptomes from this genus hinders further studies on the molecular mechanism and evolution of their carnivory habit . this dataset provides the first full - length transcriptome sequences from pitcher tissues of three well - studied nepenthes species , which is important for guiding functional genomics and proteomics studies . this will further improve our understanding on the nepenthaceae evolutionary history and contribute to gene mining for useful digestive enzymes for industrial applications . full - length cdna transcriptome profiles of three nepenthes species ( n. ampullaria , n. rafflesiana and n.    hookeriana ) were generated from the polya - enriched cdna libraries prepared from total rna extracted from whole pitchers . the sequences generated using pacbio rs ii platform from smrtbell libraries were processed using the smrt analysis server . raw data for this project were deposited in the sra database with the accession numbers srx2692198 ( http://www.ncbi.nlm.nih.gov/sra/srx2692198 ) for n. ampullaria , srx2692197 ( http://www.ncbi.nlm.nih.gov/sra/srx2692197 ) for n. rafflesiana , and srx2692196 ( http://www.ncbi.nlm.nih.gov/sra/srx2692196 ) for n.    hookeriana . all three species of pitcher plants were growing together on a terrace ( 25511.5n 1014701.4e ) next to experimental plots at universiti kebangsaan malaysia , bangi . whole mature pitchers were collected in the morning within 24  h of pitcher opening in june 2015 , emptied and frozen in liquid nitrogen before stored in   80  c for further use . quantity and integrity of extracted total rna were determined using nanodrop ( thermo fisher scientific inc . , one sample for each species was sequenced using on the pacific biosciences rs ii platform with one smrt cell v3 each based on p6-c4 chemistry after standard full - length cdna ( 13  kb ) library preparation protocol ( smrtbell template preparation kit 1.0 ) at icahn medical institute ( mount sinai , new york city , usa ) . sequence movie files from all three data sets were processed and analysed through iso - seq pipeline ( rs_isoseq protocol ) using pacbio smrt analysis server v2.3.0 ( http://www.pacb.com/products-and-services/analytical-software/smrt-analysis/ ) to filter out polymerase read reads <  50  bp and quality <  0.75 with 0 minimum full passes ( table 1 ) . filtered reads were further classified (   300  bp , full - length reads do not require poly - a tails , and 0 maximum number of paths per isoform / read ) , and clustered using ice algorithm ( estimated cdna size 12  kb ) with quiver polishing ( quality    0.99 ) to generate consensus isoform sequences . further information on the different reads generated can be found in pacbio wiki ( https://github.com/pacificbiosciences/cdna_primer/wiki/understanding-pacbio-transcriptome-data ) . the consensus isoform sequences can be used as full - length transcriptome references for the three species of carnivorous pitcher plants for further studies.table 1statistics of overall read filtering.table 1.metricspre-filterpost-filtertotal polymerase read bases5,208,565,5864,796,143,944number of polymerase reads450,876273,200polymerase read n50 ( bp)27,49528,186mean polymerase read length ( bp)11,55217,555mean polymerase read quality0.560.83total subread bases4,680,734,229number of subreads2,704,918subread n50 ( bp)1747mean subread length ( bp)1730table 2statistics of iso - seq of three nepenthes species.table 2.metricsn . hookeriananumber of reads of insert86,40790,07686,246read bases of insert154,845,182166,851,165164,740,830mean read length of insert ( bp)179218521910mean read quality of insert93.6%93.7%93.8%mean number of passes9.239.059.29number of five prime reads58,43358,64760,760number of three prime reads59,44863,22863,815number of poly - a reads49,16261,34761,339number of filtered short reads583456313613number of non - full - length reads32,10335,44331,027number of full - length reads48,47049,00251,606number of full - length non - chimeric reads48,14748,55251,265mean full - length non - chimeric read length ( bp)159016231668number of consensus isoforms26,13030,55833,279number of polished high - quality (   0.99 ) isoforms17,22120,25421,739number of polished low - quality ( <  0.99 ) isoforms881310,30411,540mean length of consensus isoforms ( bp)162516801722 statistics of overall read filtering . all three species of pitcher plants were growing together on a terrace ( 25511.5n 1014701.4e ) next to experimental plots at universiti kebangsaan malaysia , bangi . whole mature pitchers were collected in the morning within 24  h of pitcher opening in june 2015 , emptied and frozen in liquid nitrogen before stored in   80  c for further use . quantity and integrity of extracted total rna were determined using nanodrop ( thermo fisher scientific inc . , one sample for each species was sequenced using on the pacific biosciences rs ii platform with one smrt cell v3 each based on p6-c4 chemistry after standard full - length cdna ( 13  kb ) library preparation protocol ( smrtbell template preparation kit 1.0 ) at icahn medical institute ( mount sinai , new york city , usa ) . sequence movie files from all three data sets were processed and analysed through iso - seq pipeline ( rs_isoseq protocol ) using pacbio smrt analysis server v2.3.0 ( http://www.pacb.com/products-and-services/analytical-software/smrt-analysis/ ) to filter out polymerase read reads <  50  bp and quality <  0.75 with 0 minimum full passes ( table 1 ) . filtered reads were further classified (   300  bp , full - length reads do not require poly - a tails , and 0 maximum number of paths per isoform / read ) , and clustered using ice algorithm ( estimated cdna size 12  kb ) with quiver polishing ( quality    0.99 ) to generate consensus isoform sequences . further information on the different reads generated can be found in pacbio wiki ( https://github.com/pacificbiosciences/cdna_primer/wiki/understanding-pacbio-transcriptome-data ) . the consensus isoform sequences can be used as full - length transcriptome references for the three species of carnivorous pitcher plants for further studies.table 1statistics of overall read filtering.table 1.metricspre-filterpost-filtertotal polymerase read bases5,208,565,5864,796,143,944number of polymerase reads450,876273,200polymerase read n50 ( bp)27,49528,186mean polymerase read length ( bp)11,55217,555mean polymerase read quality0.560.83total subread bases4,680,734,229number of subreads2,704,918subread n50 ( bp)1747mean subread length ( bp)1730table 2statistics of iso - seq of three nepenthes species.table 2.metricsn . hookeriananumber of reads of insert86,40790,07686,246read bases of insert154,845,182166,851,165164,740,830mean read length of insert ( bp)179218521910mean read quality of insert93.6%93.7%93.8%mean number of passes9.239.059.29number of five prime reads58,43358,64760,760number of three prime reads59,44863,22863,815number of poly - a reads49,16261,34761,339number of filtered short reads583456313613number of non - full - length reads32,10335,44331,027number of full - length reads48,47049,00251,606number of full - length non - chimeric reads48,14748,55251,265mean full - length non - chimeric read length ( bp)159016231668number of consensus isoforms26,13030,55833,279number of polished high - quality (   0.99 ) isoforms17,22120,25421,739number of polished low - quality ( <  0.99 ) isoforms881310,30411,540mean length of consensus isoforms ( bp)162516801722 statistics of overall read filtering .
tropical pitcher plants in the species - rich nepenthaceae family of carnivorous plants possess unique pitcher organs . 
 hybridisation , natural or artificial , in this family is extensive resulting in pitchers with diverse features . 
 the pitcher functions as a passive insect trap with digestive fluid for nutrient acquisition in nitrogen - poor habitats . 
 this organ shows specialisation according to the dietary habit of different nepenthes species . in this study 
 , we performed the first single - molecule real - time isoform sequencing ( iso - seq ) analysis of full - length cdna from nepenthes ampullaria which can feed on leaf litter , compared to carnivorous nepenthes rafflesiana , and their carnivorous hybrid nepenthes    hookeriana . 
 this allows the comparison of pitcher transcriptomes from the parents and the hybrid to understand how hybridisation could shape the evolution of dietary habit in nepenthes . 
 raw reads have been deposited to sra database with the accession numbers srx2692198 ( n. ampullaria ) , srx2692197 ( n. rafflesiana ) , and srx2692196 ( n.    hookeriana ) .