The SlWRKY57-SlVQ21/SlVQ16 module regulates salt stress in tomato

Salt stress is a major abiotic stress which severely hinders crop production.However,the regulatory network controlling tomato resistance to salt remains unclear.Here,we found that the tomato WRKY transcription factor WRKY57 acted as a negative regulator in salt stress response by directly attenuating the transcription of salt-responsive genes(Sl RD29B and Sl DREB2)and an ion homeostasis gene(Sl SOS1).We further identified two VQ-motif containing proteins Sl VQ16 and Sl VQ21as Sl WRKY57-interacting proteins.Sl VQ16 positively,while Sl VQ21 negatively modulated tomato resistance to salt stress.Sl VQ16 and Sl VQ21 competitively interacted with Sl WRKY57 and antagonistically regulated the transcriptional repression activity of Sl WRKY57.Additionally,the Sl WRKY57-Sl VQ21/Sl VQ16 module was involved in the pathway of phytohormone jasmonates(JAs)by interacting with JA repressors JA-ZIM domain(JAZ)proteins.These results provide new insights into how the Sl WRKY57-Sl VQ21/Sl VQ16 module finely tunes tomato salt tolerance.