内生真菌与植物的互利共生在促进生长、提高抗逆性方面发挥重要作用。印度梨形孢(Piriformospora. indica)，通过和植物根部形成共生关系，能促进植物生长并诱导宿主的系统抗性。前期研究中，我们发现大麦激素代谢途径关键酶-贝壳杉烯合成酶(HvKSL1和HvKSL4，KS)影响P. indica定殖。在此基础上，本项目拟研究其调控P. indica定殖的分子机制。本项目基于大麦根部遗传转化获得KS沉默和过表达植株，结合高效液相色谱-质谱技术阐释该基因功能；结合扫描电镜及生化检测，鉴定KS差异表达对P. indica定殖的早期影响；基于转录组学及代谢组学挖掘大麦在激素代谢途径的差异表达基因和P. indica的效应子；利用定量PCR，明确差异基因表达；综合以上阐明大麦KS基因调控P. indica定殖的分子机制。研究结果将为深入理解植物与微生物互作及提高农作物产量等方面提供理论依据。

The interaction of mutualism between mutualistic symbioses fungus with crop plant plays a key role in promoting plant growth, improving the resistance against adversity stress. Piriformospora indica, by forming a symbiotic relationship with plant root, can promote plant growth and induce systemic resistance. In the previous study, we found that the key enzymes - Kaurene Synthases (HvKSL1 and HvKSL4, KS) involved in barley hormone metabolism affected P. indica colonization. On this basis, this project intends to study the molecular mechanism of endophytic fungus P. indica colonization in barley regulated by KS genes. .By combination of barley stable root transformation system and high performance liquid chromatography (HPLC) - mass spectrometry, the KS gene function will be elucidated by gene silencing, overexpression and metabolites identification; Combined with scanning electron microscopy and biochemical detection, KS differential expression affecting P. indica colonization will be identified in the early stage. Differential expressed genes in hormone metabolic pathways of barley and effector in P. indica will be mined based on transcriptional proteomics and metabolomics techniques. Differential expressed genes will be illustrated relying on the real-time PCR. Taking what is above-mentioned into account, the molecular mechanism of endophytic fungus P. indica colonization in barley regulated by KS genes will be clarified. The research results will provide the theoretical basis for deeply understanding of interaction between plant and microorganism and improving crop yields.