AUTHOR=Zhang Tingfu , Wen Guoqin , Song Bo , Chen Zhenyong , Jiang Shijiao 

TITLE=Transcriptome profiling reveals the underlying mechanism of grape post-harvest pathogen Penicillium olsonii against the metabolites of Bacillus velezensis

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1019800

DOI=10.3389/fmicb.2022.1019800

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Pathogen infection influences the post-harvest shelf life of grape berries. In a preliminary study, metabolites produced by <italic>Bacillus velezensis</italic> significantly inhibited the growth of the grape postharvest pathogen <italic>Penicillium olsonii</italic>.</p></sec><sec><title>Methods</title><p>To investigate the mechanism of interaction between <italic>B. velezensis</italic> and <italic>P. olsonii</italic>, a draft genome was generated for <italic>P. olsonii</italic> WHG5 using the Illumina NovaSeq platform, and the transcriptomic changes in WHG5 were analyzed in response to the exposure to <italic>B. velezensis</italic> metabolites (10% v/v).</p></sec><sec><title>Results</title><p>The expression levels of genes associated with sporulation, including <italic>GCY1</italic>, <italic>brlA</italic>, and <italic>abaA</italic>, were down-regulated compared with those of the control. In addition, spore deformation and abnormal swelling of the conidiophore were observed. The expression of crucial enzymes, including fructose 2,6-bisphosphate and mannitol-2-dehydrogenase, was down-regulated, indicating that the glycolytic pathway of WHG5 was adversely affected by <italic>B. velezensis</italic> metabolites. The KEGG pathway enrichment analysis revealed that glutathione metabolism and the antioxidant enzyme system were involved in the response to <italic>B. velezensis</italic> metabolites. The down-regulation of the pathogenesis-related genes, <italic>PG1</italic> and <italic>POT1</italic>, suggested that <italic>B. velezensis</italic> metabolites decreased the pathogenicity of <italic>P. olsonii</italic>. <italic>B. velezensis</italic> metabolites disrupted the homeostasis of reactive oxygen species in <italic>P. olsonii</italic> by affecting glucose metabolism, resulting in spore deformation and disruption of growth. In addition, the expression of key pathogenesis-related genes was down-regulated, thereby reducing the pathogenicity of <italic>P. olsonii</italic>.</p></sec><sec><title>Disscusion</title><p>This study provides insights into the responses of <italic>P. olsonii</italic> to <italic>B. velezensis</italic> metabolites and identifies potential target genes that may be useful in biocontrol strategies for the suppression of post-harvest spoilage in grapes.</p></sec>