Botrytis cinerea Transcriptome during the Infection Process of the Bryophyte Physcomitrium patens and Angiosperms

Botrytis cinerea is a necrotrophic pathogen that causes grey mold in many plant species, including crops and model plants of angiosperms. B. cinerea also infects and colonizes the bryophyte Physcomitrium patens (previously Physcomitrella patens), which perceives the pathogen and activates defense mechanisms. However, these defenses are not sufficient to stop fungal invasion, leading finally to plant decay. To gain more insights into B. cinerea infection and virulence strategies displayed during moss colonization, we performed genome wide transcriptional profiling of B. cinerea during different infection stages. We show that, in total, 1015 B. cinerea genes were differentially expressed in moss tissues. Expression patterns of upregulated genes and gene ontology enrichment analysis revealed that infection of P. patens tissues by B. cinerea depends on reactive oxygen species generation and detoxification, transporter activities, plant cell wall degradation and modification, toxin production and probable plant defense evasion by effector proteins. Moreover, a comparison with available RNAseq data during angiosperm infection, including Arabidopsis thaliana, Solanum lycopersicum and Lactuca sativa, suggests that B. cinerea has virulence and infection functions used in all hosts, while others are more specific to P. patens or angiosperms.