Sodium pyrosulfite inhibits the pathogenicity of Botrytis cinerea by interfering with antioxidant system and sulfur metabolism pathway

Grapes are cultivated worldwide and are favored by consumers for their delicious taste and nutritional value. Grey mould, caused by Botrytis cinerea, leads to considerable loss of postharvest grape fruit each year. Sulfur dioxide fumigation is widely used to inhibit grey mould of grape around the world, but there is still a lack of research on its antimicrobial mechanism, especially at molecular level. In present study, we explored the molecular mechanisms of sulfur dioxide against B. cinerea in vitro and in vivo, respectively, using the sulfur dioxide donor sodium pyrosulfite. The results indicated that sodium pyrosulfite treatment could inhibit the expression of genes in antioxidant system and sulfur metabolism pathway of B. cinerea. The down-regulated genes in sulfur metabolism were mainly involved in the process of assimilatory sulfate reduction, limiting the synthesis of sulfur-containing organic compounds. Furthermore, the expressions of several critical antioxidant genes were suppressed under the sodium pyrosulfite stress. The decrease of antioxidant capacity led to ROS accumulation in B. cinerea cell, resulting in the decrease of the survival rate. These results not only richen our understanding of the antimicrobial mechanisms of sulfur dioxide against B. cinerea at the molecular level, but also are beneficial for us to improve sulfur dioxide product in the future.

Automated summary

In this study, the molecular mechanisms of sulfur dioxide against Botrytis cinerea were explored in vitro and in vivo using sodium pyrosulfite. The results showed that sodium pyrosulfite treatment inhibited the expression of genes related to the antioxidant system and sulfur metabolism pathway in B. cinerea, resulting in decreased survival rate. These findings enhance our understanding of the antimicrobial mechanisms of sulfur dioxide at the molecular level and have implications for future improvement of sulfur dioxide products.