The SlARF6A-SlFBA3/SlSGR Module Regulates the Resistance of Tomatoes to Pseudomonas syringae pv. tomato

Bacterial leaf spot disease is among the most common diseases affecting tomato production. It is caused by Pseudomonas syringae pv. tomato (Pst) and severely affects tomato plant growth, development, and yield. In this study, we identified a fructose-1,6-diphosphate aldolase gene, SlFBA3, whose expression was significantly increased in the tomato pathway for resistance to Pst. Overexpression of SlFBA3 enhanced tomato plant resistance, whereas knockout of SlFBA3 reduced the resistance of tomato plants. Further analysis revealed that SlSGR is an interacting protein of SlFBA3. Functional analysis showed that overexpression of SlSGR inhibited the resistance of tomato to Pst, whereas knockout of SlSGR increased resistance. Mechanistically, upon flg22 and csp22 elicitation, SlFBA3 can enhance the early immune signalling pathway, while SlSGR inhibits this response. Notably, we found that SlFBA3 can partially antagonize the function of SlSGR, thereby weakening the negative regulatory role of SlSGR in the disease response. In addition, we discovered that the positive regulatory factor SlARF6A of this disease-resistant response can target and regulate the transcriptional activation activity of SlFBA3. In conclusion, we revealed that the SlARF6A-SlFBA3/SlSGR module plays an important role in the resistance response of tomato to Pst, providing a new research direction for disease resistance breeding in tomato.