increased photosynthetic capacities of host plants as well as improved water relations. Improvements in water use efficiency were observed in higher concentrations and a further increase was seen in water deficit conditions. In addition, other various physiological pathways were activated upon endophytes interactions with host plants, enabling tighter water control and further water management, which are to be the main reasons behind improved water relations. Specifically, evidence points to endophytes producing ABA to affect stomatal conductance as well as microbial respiration and plants recycling . However, the specific biochemical mechanisms behind these behavioral changes are still largely unknown and lower-level signal cascades have yet to be discovered. Furthermore, while the benefits of endophyte relations are well-studied, the costs of these relations are less well understood, such as the specific carbon costs, the system of endophyte governance, and the environmental conditions that facilitate a proper plant-endophyte relationship. In an experiment investigating the interaction between Miscanthus sinensis and the plant endophyte Herbaspirillum frisingense, a roughly 20% increase in fresh biomass was observed in M. sinensis following inoculation with H. frisingense. However, unique to this experiment was the mode by which this was thought to happen. Inoculation saw an upregulation in the genes relevant to jasmonate and ethylene production in the plant roots, although the mechanism to this is still unknown. Specifically, H. frisingense was shown to upregulate ethylene receptors and repress ethylene response factors, overall leading to an increase in root growth. Additionally, H. frisingense is known to produce indoleacetic acid (IAA), and was also shown to manage IAA genes, indicating that there is an intricate balance maintained between ethylene and IAA by H. frisingense. Diversity Endophytic species are very diverse; only a small minority of existing endophytes have been characterized. Many endophytes are in the phyla Basidiomycota and Ascomycota. Endophytic fungi may be from Hypocreales and Xylariales of the Sordariomycetes (Pyrenomycetes) class or from the class of Loculoascomycetes. One group of fungal endophytes are the arbuscular mycorrhizal fungi involving biotrophic Glomeromycota associated with various plant species. As often with other organisms associated with plants such as mycorrhizal fungus, endophytes gain carbon from their association with the plant host. Bacterial endophytes are polyphyletic, belonging to broad range of taxa, including α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Firmicutes, Actinobacteria. One or more endophytic organisms are found in nearly every land plant. It is suggested that areas of high plant diversity such as tropical rainforests may also