The function of CC-type glutaredoxins in salt-induced flower drop in tomato

Salt stress significantly induces the abscission of flowers and fruits, resulting in a reduction in crop yields and posing a threat to food security. Nonetheless, the molecular mechanisms underlying the abscission triggered by salt stress remain poorly understood. In our study, the effects of different NaCl concentrations on the growth of tomato plants and flower drop were investigated. The results showed that 200 mM NaCl inhibited the growth of tomato plants and accelerated the flower drop of tomato plants. Through an RNA-Seq assay, differentially expressed genes (DEGs) in the abscission zone (AZ) under control and salt stress treatment conditions were screened. Among DEGs, the reactive oxygen species (ROS)-related pathway was the most significantly enriched pathway in the gene ontology (GO) analysis, which was consistent with the increase in ROS content in the AZ under salt treatment. Salt stress significantly induced the expression of CC-type SlGRXs in the AZ. Overexpression of SlGRX16 significantly inhibited the content of ROS in AZ and salt stress-induced flower drop. These results provide new insights and basic data for understanding the mechanisms of salt-stress-induced flower drop.