Plant Cell Wall Architecture and Fungal Pathogen Susceptibility

University Of California-Davis, Davis CA

Investigators

Abstract

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.