天然产物柠檬醛抗稻瘟病菌的分子机制研究

Rice blast disease, caused by Magnaporthe oryzae, is one of the most severe diseases of rice throughout the world and is recognized as one of the major pathological threats to China food supplies. Screening for new active compounds in natural products is an important way to solve the ecological control of blast disease. As a natural acyclic monoterpenes, citral is the major component of Litsea cubeba oil which was extracted from its fruits, present at levels. Our previous study results showed that citral may act by disrupting cell wall integrity and membrane permeability, thus resulting in physiology changes and causing cytotoxicity. In recent years, several studies reported that citral was capable of preventing plant pathogen, such as M. oryzae, but the active components of citral and their pharmacological effects are still unclear. The objectives of this work are (i) to screen and annotate the differential expressed genes of M. oryzae after treatment with citral using transcriptome sequencing, (ii) to ascertain the expression profiles of differential expressed genes at the different developmental stages of M. oryzae，and (iii) to study its effect on the growth and development of rice blast fungus using RNAi technology. The aim of the present study is not only to develop a new plant-based fungicide of citral, but also to provide the important scientific basis and clue for the rational design of biological fungicides.

水稻稻瘟病是由稻瘟病菌引起的真菌病害，是影响我国水稻安全生产的严重病害，天然产物中新活性化合物的筛选是解决稻瘟病生态防控的重要途径。项目申请人前期工作明确天然产物柠檬醛对稻瘟病菌细胞壁膜及生理代谢具有显著破坏作用，为了进一步明确其作用机制，本研究以水稻稻瘟病菌为研究对象，运用分子生物学和生物信息学理论，首先，采用高通量转录组测序（RNA-Seq）技术，筛选柠檬醛处理后稻瘟病菌中表达差异显著的基因并进行功能注释；其次，利用荧光定量PCR技术研究明确上述差异表达基因在稻瘟病菌不同发育阶段的表达谱；最后，利用RNAi技术沉默上述差异表达的基因，研究其对稻瘟病菌生长发育的影响，从而明确这些基因的功能。研究结果将发现柠檬醛抗稻瘟病菌的新型靶标，不仅有望开发出防治水稻稻瘟病的天然植物源农药，而且可为杀菌剂的生物合理设计提供重要的科学依据和线索。

水稻稻瘟病是由稻瘟病菌引起的真菌病害，是影响我国水稻安全生产的严重病害，天然产物中新活性化合物的筛选是解决稻瘟病生态防控的重要途径。项目申请人前期工作明确天然产物柠檬醛对稻瘟病菌细胞壁膜及生理代谢具有显著破坏作用，为了进一步明确其作用机制，本研究以水稻稻瘟病菌为研究对象，运用分子生物学和生物信息学理论，研究柠檬醛抗稻瘟病菌的分子机制。柠檬醛胁迫下稻瘟病菌氨基糖和核苷酸糖代谢通路分析表明，14个基因产生显著变化，其中显著上调的基因包括有MGG_03920、MGG_14956等6个，显著下调的基因有MGG_08985、MGG_12291等8个。其中稻瘟病菌几丁质酶18家族的15个基因响应柠檬醛的基因表达情况进行分析，发现MGG_00086、MGG_ 08458表达量上调，并构建沉默突变菌株。初步研究表明，柠檬醛可能作用于水稻稻瘟病菌几丁质酶基因MGG-00086和MGG-08458，为进一步探究柠檬醛对稻瘟病菌几丁质酶基因研究MGG-00086和MGG-08458的调控机制提供依据。