茶树炭疽菌MAPK信号转导通路调控炭疽菌致病力的作用机制研究

Brown blight disease caused by Colletotrichum species is one of the major foliar diseases on tea plant (Camellia sinensis) prevalent in China and is difficult to control. For better understanding the targets of Colletotrichum gloeosporioides on tea plant, it is crucial to find pathogenesis-related genes. But so far, there are no reports on the pathogenesis-related genes of Colletotrichum species on tea plant. Mitogen-activated Protein Kinase (MAPK)-mediated signaling transduction pathway is emphasized by its evolutionary conservation, which involves in fungal infection process such as mycelial growth, conidia germination and appressorium formation. In this study, according to the conserved MAPK sequences of three Colletotrichum species, of which the whole genome sequences have been published, a gene designated CsCMKl in MAPK pathway of C. gloeosporioides on tea plant was cloned. The eGFP (enhanced green fluorescent protein)-marked agrobacterium tumefaciens transformation system was established and RNA interference (RNAi) was used to study the function of gene CsCMK1 in MAPK pathway in regulating the pathogenicity of C.gloeosporioides on tea plant, which can uncover the infection process and pathogenic molecular mechanism of C.gloeosporioides. These results are significant for finding molecular targets, developing new effective fungicides and providing new control strategies.

由炭疽菌属（Colletotrichum）真菌引起的茶树叶部病害是茶树的主要病害之一，生产上很难控制该病的发生和流行。为了更好的获得防治茶树炭疽菌的作用靶标，寻找致病关键因子至关重要。但至今为止，一直未有茶树炭疽菌致病相关基因的报道。促分裂原活化蛋白激酶（Mitogen-activated Protein Kinase, MAPK）介导的信号转导途径在进化上非常保守，参与炭疽菌侵染丝生长、分生孢子萌发、附着胞形成等各个侵染过程。本研究基于已公布的3种炭疽菌全基因组序列信息和MAPK途径在调控真菌致病性方面的保守性，克隆茶树胶胞炭疽菌 (C. gloeosporioides) MAPK途径基因CsCMK1，并以增强型绿色荧光蛋白eGFP为标记基因，建立农杆菌介导的遗传转化体系，通过RNAi技术研究CsCMK1在调控茶树炭疽菌致病力上的功能，以揭示炭疽菌在茶树中的侵染过程及致病分子机制。

由炭疽菌属（Colletotrichum）真菌引起的茶树叶部病害是茶树的主要病害之一，生产上很难控制该病的发生和流行。为了更好的获得防治茶树炭疽菌的作用靶标，寻找致病关键因子至关重要。但至今为止，一直未有茶树炭疽菌致病相关基因的报道。促分裂原活化蛋白激酶（Mitogen-activated protein kinase, MAPK）介导的信号转导途径在进化上非常保守，参与炭疽菌侵染丝生长、分生孢子萌发、附着胞形成等各个侵染过程。本研究基于已公布的3种炭疽菌全基因组序列信息和MAPK途径在调控真菌致病性方面的保守性，克隆了茶树胶胞炭疽菌(C. gloeosporioides) MAPK途径基因CsCMK1，建立了PEG介导的遗传转化体系，并采用同源重组方法构建并获得了目的基因的突变菌株，明确了CsCMK1在调控茶树炭疽菌致病力上的功能。在项目实施过程中，项目主持人从重庆感病茶园中分离获得了部分茶树炭疽菌新种，研究发现不同炭疽菌种之间的特征特性差异较大，且通过初步试验证实不同菌种之间的基因序列也存在较大的差异性，因此，项目主持人拟在此项目基础上继续进行不同炭疽菌种的相同基因的功能研究，并借助本项目建立的功能基因研究方法，结合转录组学数据基础，开展更多候选基因的功能研究，以更全面的解析炭疽菌的致病机制，为炭疽菌的病害防治制定更有效的策略。