The ethylene response factor SlERF.B8 triggers jasmonate biosynthesis to promote cold tolerance in tomato

Cold stress inhibits growth, decreases yields and impairs fruit quality in tomato (Solanum lycopersicum). Previous studies have shown that cold stress leads to increased JA accumulation, however, how jasmonate biosynthesis is regulated upon cold stress remains largely unknown. Here, we report an ethylene response factor SlERF.B8 that acts as a crucial regulator of JA biosynthesis in tomato under cold stress. Transcription of SlERF.B8 was markedly enhanced by JA and cold stress, and silencing of SlERF.B8 led to decreased JA accumulation and attenuated cold tolerance in tomato. ChIP-qPCR and dual-luciferase assays showed that SlERF.B8 functions as a transcriptional activator of JA biosynthesis genes, including LOXD, AOC and OPR3. Furthermore, MYC2, a critical mediator of JA signaling, activates the transcription of SlERF.B8, thus forming a positive feedback loop, which amplifies the output of JA signaling. Taken together, our data favor that SlERF.B8 is a key regulator of JA biosynthesis and cold tolerance in tomato plants.