胶孢炭疽病菌CFEM型效应蛋白对巴西橡胶树的致病分子机理研究

Rubber tree anthracnose, mainly caused by the fungus Colletotrichum gloeosporioides, is one of the major constraints in rubber production. Fungal effectors play important role in pathogenicity. CFEM (Common in Fungal Extracellular Membrane) type effectors were named after its amino acid sequences with conserved CFEM domain and involved in the development and pathogenicity of fungal pathogens. However, the pathogenic mechanisms of CFEM type effectors are not clear. Based on the genomic sequence of C. gloeosporioides, three CFEM effector encoding genes, named as CgCFEM1，CgCFEM2 and CgCFEM3 (CgCFEM1-3), were identified and CgCFEM1-3 knockout mutants showed impaired pathogenicity on rubber tree leaves. In this project, we propose to investigate the effect of CgCFEM1-3 on innate immunity responses in rubber tree and to isolate the targets of CgCFEM1-3 in rubber tree to illuminate how CFEM type effectors contribute to the virulence in host plant. The outcomes of this project will provide fundamental basis for new strategy to control rubber tree anthracnose.

胶孢炭疽病菌引起的橡胶树炭疽病是天然橡胶减产的重要因素之一。真菌效应蛋白是重要的致病因子，在植物病害发生中起关键作用。CFEM型效应蛋白是一类含有CFEM保守结构域的胞外分泌蛋白，也是真菌重要的致病因子，目前还没有胶胞炭疽菌CFEM的相关研究。我们完成了胶孢炭疽菌基因组的测序，预测出3个含CFEM结构域的效应蛋白基因并命名为CgCFEM1，CgCFEM2和CgCFEM3，它们的基因敲除突变体对橡胶树的致病性均明显减弱。本项目拟在此基础上，通过分析CgCFEM1-3对橡胶树免疫反应的影响，分离它们在橡胶树中的靶标因子，阐明CgCFEM1-3对橡胶树的致病机理。本项目利用橡胶树叶片原生质体瞬时表达系统研究效应蛋白对橡胶树先天免疫反应的影响，不仅可以深入理解CgCFEM1-3对橡胶树的作用机理，也为建立新的橡胶树炭疽病防控策略提供理论依据。

胶孢炭疽病菌引起的橡胶树炭疽病是天然橡胶减产的重要因素之一。真菌效应蛋白是重要的致病因子，在植物病害发生中起关键作用。CFEM型效应蛋白是一类含有CFEM保守结构域的胞外分泌蛋白，也是真菌重要的致病因子。本项目鉴定了胶胞炭疽菌中的3个CFEM类效应蛋白CgCFEM1、CgCFEM2和CgCFEM3，研究结果表明，CgCFEM1、2、3在对橡胶的致病性中发挥重要作用，其中CgCFEM1和CgCFEM2在病菌致病力中具有相互促进作用。CgCFEM1和CgCFEM2 不仅影响胶胞炭疽菌的孢子形态、产孢量和侵染结构的发育，还能够抑制由chitin引起的橡胶树的PTI反应。此外，CgCFEM1与Fe2+的吸收相关， CgCFEM2可能与Fe3+的转化相关且参与胶胞炭疽菌的自噬调控。本研究结果阐明了CFEM类效应蛋白介导的胶胞炭疽菌对橡胶树的致病机理，为建立新的橡胶树炭疽病防控策略提供理论依据。