The transcriptomic landscape of Botrytis cinerea infection on postharvest grapes sheds light on the biological function of the Bcnrps1 gene

Botrytis cinerea, a prevalent necrotrophic fungal pathogen, causes significant postharvest infections including fruits. This pathogen exploits senescent tissues, resulting in significant economic losses. During the Botrytis-plant interaction, a molecular cross-talk is established between the host and the pathogen, mediated by the interplay of the plant's defense pathways and the phytopathogenic fungus's virulence pathways, which are modulated by abiotic and biotic factors.

The Bcnrps1 genes is secondary metabolims gene that encodes a non-ribosomal peptide synthetase. This family enzyme is responsible for the synthesis of natural peptides with a wide range of biological activities. Although the function of the majority of these peptides remains elusive, they could evolve in plant-pathogen interaction during infection process. Deletion of the Bcnrps1 gene increases the virulence of the pathogen otherwise, a reduction in sensitivity to toxic compounds such as spermidine and the fungicide pyrimethanil is observed. A transcriptome analysis was performed in this study to comprehensively elucidate the behavior of this mutant and to assess the molecular dynamics both in Bcnrps1 mutant and wild-type strains during the infection process of harvested white grapes. The number of differentially expressed genes (DEGs) during infection differs significantly between the B. cinerea B05.10 strain and the ΔBcnrps1 strain. The results demonstrate that, during white grape infection, the mutant induces genes related to five main functional groups: detoxification, transcription factors, CAZymes, virulence factors, and secondary metabolism. These findings underscore the crucial role of the Bcnrps1 gene in mediating the fungal response to environmental stressors and plant-derived substances during plant-pathogen interactions, as supported by observed gene expression patterns.