Identification of HsfA9 and a network of regulators involved in resistance to bacterial wilt under high temperature in tomato.

Bacterial wilt (BW), caused by Ralstonia solanacearum, is a highly destructive disease in tomato, and resistance to BW is attenuated under high temperature (HT). However, limited information is available with respect to the molecular basis of tomato-R. solanacearum interactions under HT. Here, we conducted transcriptomic analysis on the root-stem junction tissues of tomatoes exhibiting varying levels of BW resistance at 0, 12, 24, and 48 h post-inoculation (hpi) with R. solanacearum under 33 °C. Weighted gene co-expression network analysis (WGCNA) revealed two modules containing key genes that participated in disease resistance under HT. A total of 91 core genes were identified as potentially coordinating immune signaling and metabolic homeostasis during the interactions between tomato and R. solanacearum. Ultimately, we identified HsfA9 as a key transcription factor potentially involved in bacterial wilt resistance under HT. Our findings provide a valuable resource for elucidating the molecular mechanism underlying of R. solanacearum-tomato interactions under HT, thereby facilitating the development of effective strategies in disease control and prevention.