茉莉酸信号通路对褐飞虱偏好取食二化螟为害稻株的调控机制

Chilo suppressalis and Nilaparvata lugens are two important economic pests on rice. The interspecific relationship between them is of great importance to the control of pests and the evaluation of rice germplasm resistance. The applicant's previous research found that the specific preference-performence of N.lugens on the rice plants damaged by C.suppressalis, analysis of the metabolome data shows that the level of jasmonic acid increased significantly in the damaged rice plant. Based on those, this project intends to carry out the impact of the growth, development, survival, reproduction and feeding behavior of N.lugens on C.suppressalis-damaged rice, and determine jasmonic acid levels, the changes of volatile and secondary metabolites after C.suppressalis damaged. qPCR is used to determine the differentially expressed genes in the jasmonic acid signal pathway after C.suppressalis damaged; RNA interference and overexpression to identify the functions of key genes on the jasmonic acid signal pathway. Ultimately, physiological and molecular mechanisms of N.lugens preference to C.suppressalis–damaged rice plant is elucidated. This study is expected to enrich the theory of rice-mediated insects interactions, providing a theoretical basis for the prevention and control of N.lugens and evaluation of N.lugens rice germplasm resistance.

褐飞虱和二化螟均为我国水稻上的重要害虫，二者在水稻上取食为害的种间互作关系对害虫防控及水稻种质抗性评价均具有重要意义。申请人前期研究发现：褐飞虱偏好取食二化螟为害稻株；相关代谢组学数据表明：螟害稻株的茉莉酸水平显著上升。基于此，本项目拟开展二化螟为害稻株对褐飞虱生长发育、存活、生殖及取食行为的影响，测定水稻植株被害后体内茉莉酸水平、挥发性物含量及次生物质变化；获取对褐飞虱高活性的挥发性物质的信息化合物、鉴定次生物质有效成分，并分别测定挥发性信息化合物及次生物质对褐飞虱取食行为的影响；采用qPCR测定稻株被二化螟为害后茉莉酸信号通路上关键基因的表达丰度；应用RNA干扰和过量表达等技术手段构建转基因稻株，明确茉莉酸信号通路上关键基因的功能，进而阐明褐飞虱偏好取食二化螟为害株的生化和分子机制。该研究可望丰富水稻介导的昆虫种间互作关系理论，为褐飞虱防控和抗褐飞虱种质评价提供理论依据。

褐飞虱和二化螟在水稻上取食为害的种间互作关系对害虫防控及水稻种质抗性评价均具有重要意义。本项目研究发现褐飞虱偏好取食二化螟为害稻株，且二化螟为害稻株会对褐飞虱生长发育、存活、生殖及取食行为均产生影响。本项目还测定了水稻植株被害后体内茉莉酸水平、挥发性物含量及次生物质变化，结果发现二化螟为害会显著影响稻株内茉莉酸水平的变化；共获得115种挥发物，二化螟为害抗性水稻有显著性差异物质34种、新增47种挥发物；共获得114种有显著性差异的代谢物。获取了对褐飞虱高活性的挥发性物质的信息化合物、鉴定了次生物质有效成分，并分别测定了挥发性信息化合物及次生物质对褐飞虱取食行为的影响。目前已对20种挥发性物质进行高低浓度的褐飞虱趋避反应，发现有6种挥发物对褐飞虱有显著的吸引作用；对1种代谢物β-谷甾醇进行了梯度浓度生测实验，发现对褐飞虱的生长发育有抑制作用。采用实时荧光定量PCR技术测定了稻株被二化螟为害后茉莉酸信号通路上关键基因的表达丰度。本项目研究结果明确了褐飞虱偏好取食二化螟为害株的生化和分子机制，阐明了茉莉酸信号通路上关键基因的功能。该研究结果丰富了水稻介导的昆虫种间互作关系内容，为褐飞虱防控和抗褐飞虱种质评价提供理论依据。