PT  - JOURNAL ARTICLE
AU  - Thomas Leisen
AU  - Janina Werner
AU  - Patrick Pattar
AU  - Edita Ymeri
AU  - Frederik Sommer
AU  - Michael Schroda
AU  - David Scheuring
AU  - Matthias Hahn
TI  - Multiple knockout mutants reveal a high redundancy of phytotoxic compounds that determine necrotrophic pathogenesis of <em>Botrytis cinerea</em>
AID  - 10.1101/2021.08.21.457223
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.08.21.457223
4099  - http://biorxiv.org/content/early/2021/08/22/2021.08.21.457223.short
4100  - http://biorxiv.org/content/early/2021/08/22/2021.08.21.457223.full
AB  - Botrytis cinerea is a major pathogen of more than 1400 plant species. During infection, the kills host cells during infection and spreads through necrotic tissue, which is believed to be supported by induction of programmed plant cell death. To comprehensively evaluate the contributions of most of the currently known plant cell death inducing proteins (CDIPs) and metabolites for necrotrophic infection, an optimized CRISPR/Cas protocol was established which allowed serial marker-free mutagenesis to generate Botrytis mutants lacking up to 12 different CDIPs. Infection analysis revealed a decrease in virulence with increasing numbers of knockouts, and differences in the effects of knockouts on different host plants. The on planta secretomes obtained from these mutants revealed substantial remaining necrotic activity after infiltration into leaves. Our study has addressed for the first time the functional redundancy of virulence factors of a fungal pathogen, and demonstrates that B. cinerea releases a highly redundant cocktail of proteins and metabolites to achieve necrotrophic infection of a wide variety of host plants.Competing Interest StatementThe authors have declared no competing interest.