Physiological, biochemical and transcriptome analysis reveals the potential role of ABA in Dufulin induced tomato resistance to tomato brown rugose fruit virus (ToBRFV)

The application of plant immunity inducers to activate antiviral resistance has emerged as an effective plant protection strategy. This study demonstrates that Dufulin effectively controls Tomato brown rugose fruit virus (ToBRFV) infection in tomatoes. To systematically elucidate the mechanism of Dufulin-induced resistance against ToBRFV, we conducted integrated physiological, biochemical, and transcriptomic analyses. Dufulin treatment significantly increased the chlorophyll content, elevated the activities of SOD, POD and CAT, reduced the ToBRFV viral load and enabled plants to grow better. Phytohormone assay showed that Dufulin significantly induced SA and ABA levels. Combined with the analysis of their synthesis and signal transduction pathway gene expression patterns, it was found that ABA might play an unrecognized role in the formation of this induced resistance. Through weighted gene co-expression network analysis (WGCNA) and cis- element analysis of the target gene promoters, we identified that SlABI5-like might be a key transcription factor for Dufulin induced tomato resistance to ToBRFV, and initially constructed its molecular regulatory network. These findings provide new insights into uncovering the mechanism of Dufulin-induced antiviral resistance, and also provide important molecular targets for ToBRFV prevention and control.