Project description:The molecular regulation mechanisms involved in stress tolerance remain largely unknown. Drunken horsegrass (Achnatherum inebrians), an important perennial bunchgrass in China, forms a naturally occurring symbiosis with an asexual symbiotic fungus Neotyphodium gansuense.To gain insight into the molecular mechanisms involved in the low temperature resistance of E+ drunken horsegrass, Solexa deep-sequencing was used to identify candidate genes showing differential expression.
Project description:<p>Plant-associated microorganisms can be found in various plant niches and plays an important role in the response to environmental stress. For example, foliar fungal endophytes are known for their ability to increase host resistance to insect pests, fungal pathogens and drought. However, understanding of the effects of Epichloë endophytes on the assembly and ecological function of phyllosphere and rhizosphere-associated microorganisms under long-term cultivation remains fragmentary. The research presented in our manuscript systematically studied response of Achnatherum inebrians infected by endophyte (Epichloë gansuensis) to long-term cultivation. Five-year field trials demonstrated that E. gansuensis endophyte significantly increased host plant coverage. It revealed that Epichloë endophyte-infected plants recruits beneficial Microvirga species involved in soil carbon and nitrogen cycles by exudating key metabolites (i.e., 5-Hydroxyindoleacetic acid) to help the host obtain nutrients, thereby promoting plant growth. Moreover, in vitro test experiments further demonstrated that key metabolite could enhance plant growth by promoting Microvirga enrichment.</p>
Project description:The cuticular wax serves as the outermost hydrophobic barrier of plants against nonstomatal water loss and various environmental stresses. An objective of this study was to investigate the contribution of the mutualistic fungal endophyte Epichloë gansuensis to leaf cuticular wax of Achnatherum inebrians under different soil moisture availability. Through a pot experiment and gas chromatography−mass spectrometry (GC−MS) analysis, our results indicated that the hydrocarbons were the dominant components of leaf cuticular wax, and the proportion of alcohols, aldehydes, amines, and ethers varied with the presence or absence of E. gansuensis and different soil moisture availability. Amines and ethers are unique in endophyte-free (EF) A. inebrians plants and endophyte-infected (EI) A. inebrians plants, respectively. By transcriptome analysis, we found a total of 13 differentially expressed genes (DEGs) related to cuticular biosynthesis, including FabG, desB, SSI2, fadD, BiP, KCS, KAR, FAR, and ABCB1. A model is proposed which provides insights for understanding cuticular wax biosynthesis in the association of A. inebrians plants with E. gansuensis. These results may help guide the functional analyses of candidate genes important for improving the protective layer of cuticular wax of endophyte-symbiotic plants.
