基于水稻代谢组分全基因组关联的萜烯合酶基因的功能研究

Rice is the most important crop in the world. In recent years, decreased rice yield caused by high temperature, drought, pests and other adversities has attracted worldwide public attention in the world. Terpenoids play an important role in the process of resisting to pests and diseases and the content of terpenoids varies in different rice varieties. In this study, terpenoids were extracted from the pre-use HPLC-MS and GC-MS determination of metabolites. In addition, rice metabolic components genome-wide association (mGWAS) analysis method was used to locate the genes of terpene synthase which are predicted to be involved in controlling the composition and content of terpenoids in rice. Over-expression and RNAi rice lines will also be constructed using gateway system and Agrobacterium-mediated transformation method. Then the function and mechanisms of these terpene synthase genes in pest resistance will be validated with positive transgenic rice lines. This study will provide a certain theoretical way for people to understand the function of terpene synthase genes and the functional mechanism of terpenoids in disease resistance, which will ultimately explore a new way to cultivate new rice varieties resistant to diseases and insects in the future.

水稻是全世界最重要的粮食作物之一。近年来由高温、干旱、病虫害等多种逆境带来的水稻减产已引起水稻种植区国家的关注。萜烯类化合物在水稻抵御病虫害过程中发挥了重要作用，不同水稻品种的萜烯类化合物含量不同。本研究从前期用HPLC-MS及GC-MS测定的代谢物中提取萜类化合物，利用水稻代谢组分全基因组关联（mGWAS）研究将代谢物和水稻品种的基因型关联，定位控制水稻萜类化合物成分及含量变化的萜烯合酶基因。在此基础上，从萜类化合物含量高的水稻品种中克隆相关基因，经测序鉴定正确后将基因在原核系统中表达并测定相关酶活。同时利用gateway系统构建超表达及RNAi载体并利用农杆菌介导法转化水稻，对遗传转化的超表达和RNAi品系进行抗病虫害的功能鉴定和机制研究。本研究为人们了解水稻萜烯合酶基因的功能以及萜烯类化合物参与水稻抗病虫害过程提供了一定的理论参考，为培育抗病虫害水稻新品种探索出一条新途径。

萜类化合物作为植物激素、色素、小分子植保素的合成前体或组成成分，除了在植物生长、发育中起着重要作用外，还在植物的抗逆境反应如抗虫和非生物胁迫中也发挥着重要作用。在植物体内，萜类合成酶（环化酶）是合成萜类化合物的关键酶。因此，萜类合成酶基因的克隆、分离、表达和调控成为研究热点。为进一步确证萜烯合酶基因在水稻中的功能，我们对水稻进行紫外及虫胁迫诱导处理后结合代谢研究方法GC-MS，检测到了6种单萜类物质α-蒎烯、β-月桂烯、柠檬烯、罗勒烯、芳樟醇、香叶醇，2种倍半萜类物质trans-橙花叔醇和trans-金合欢醇，同时结合转录水平的变化找到了控制这些逆境下产生萜类的关键萜烯合酶基因。在我们发现的基因中有四个基因LOC_Os01g23530、LOC_Os07g11790、LOC_Os08g07080和LOC_Os10g34790对水稻逆境胁迫诱导下挥发性萜类的产生贡献最大，同时发现了控制trans-金合欢醇和芳樟醇合成的关键位点。这一结果有助于萜类的进化研究。同时我们将LOC_Os01g23530、LOC_Os07g11790、LOC_Os08g07080和LOC_Os10g34790转化到了ZH11中，获得了稳定表达的T1代转基因植株。相关的结果已在生物工程上发表一篇，正投稿一篇英文，还有一篇英文在准备中。