Volatilome and proteome responses to Colletotrichum lindemuthianum infection in a moderately resistant and a susceptible bean genotype

We analyzed the changes in the volatilome, proteome, stomatal conductance, salicylicand jasmonic acid contents of a susceptible and a moderately resistant genotype ofcommon bean, Phaseoulus vulgaris L., challenged with Colletotrichum lindemuthianum,the causal agent of fungal anthracnose. Our results indicate differences at both proteomeand volatilome levels between the two genotypes, before and after the infection,and different defense strategies. The moderately resistant genotype hindered pathogeninfection, invasion, and replication mainly by maintaining epidermal and cell wallstructure. The susceptible genotype was not able to limit the early stages of pathogeninfection. Rather, stomatal conductance increased in the infected susceptible genotype,and enhanced synthesis of Green Leaf Volatiles and salicylic acid was observed,together with a strong hypersensitive response. Proteomic investigation provided ageneral framework for physiological changes, whereas observed variations in thevolatilome suggested that volatile organic compounds may principally representstress markers rather than defensive compounds per se.