Plant Cell Wall Architecture and Fungal Pathogen Susceptibility

所有植物细胞周围富含多糖的细胞壁的重塑可能伴随着对灰霉病菌的敏感性增加，灰霉病菌是一种腐烂大多数水果的致病真菌。番茄果实成熟是植物细胞壁解体的一个例子，这与病原菌敏感性的增加相吻合。虽然成熟的番茄果实和灰霉病菌表达相似的植物细胞壁降解酶，但先前的研究表明，成熟果实产生的酶对与成熟相关的敏感性增加至关重要。观察到并不是所有未成熟的番茄突变体都对灰霉病具有抗性，这表明一些但不是所有的成熟事件是导致果实容易腐烂的原因。使成熟水果变得敏感的机制(S)包括细胞壁分解，在抗病原反应有限的情况下为灰霉病菌提供可获得的营养。这个项目确定了1)果实细胞壁重塑蛋白的多糖靶标，2)灰霉病菌与果实基因表达的变化，以及3)由这两个相互作用蛋白产生的蛋白质，将壁结构的特定成分与病原菌的感知和随后的敏感性联系起来。研究人员在多糖特性以及同步的植物和病原体转录组和蛋白质组分析方面的专业知识使人们能够评估壁结构、感染和成熟，从而扩大了对真菌分解策略的多样性和植物反应的可塑性的了解。该项目使用了一种在经济上具有重要意义的病原体和水果；该结果可能适用于其他作物和其外壁结构被改变的植物部分。研究人员与美国和国际农业部门有着密切的联系，加强了高中和本科生的教育，包括来自哥斯达黎加和墨西哥农业社区的个人，以及来自服务不足的小型本科和技术机构的个人。

Remodeling of the polysaccharide-rich cell wall surrounding all plant cells may accompany increased susceptibility to Botrytis cinerea, a pathogenic fungus that rots most fruit. Tomato fruit ripening is an example of plant cell wall disassembly that coincides with increased pathogen susceptibility. While ripening tomato fruit and Botrytis express similar plant cell wall degrading enzymes, previous work demonstrated that the enzymes produced by ripening fruit are crucial for the ripening-associated increase in susceptibility. Observations that not all non-ripening tomato mutants are resistant to Botrytis, suggested that some, but not all, ripening events are responsible for fruit susceptibility to decomposition. The mechanism(s) that make ripe fruit susceptible include cell wall disassembly which provides B. cinerea with accessible nutrients in circumstances where anti-pathogen responses are limited. This project identifies 1) polysaccharide targets of fruit cell wall remodeling proteins, 2) B. cinerea and fruit gene expression changes and 3) proteins produced by both interactors, to link specific components of the wall architecture to pathogen perception and the consequent susceptibility. The researchers' expertise in polysaccharide characterization and simultaneous plant and pathogen transcriptome and proteome analyses allows evaluation of wall architecture, infection, and ripening, thereby expanding knowledge about the diversity of fungal decomposing strategies and the plasticity of plant responses. This project uses an economically significant pathogen and fruit; the results may be applied to other crop plants and plant parts whose wall architecture is altered. The researchers have strong ties to US and international agricultural sectors enhancing the education of high school and undergraduate students, including individuals from agricultural communities in Costa Rica and Mexico and from small underserved undergraduate and technical institutions.