Jasmonate signaling pathway confers salt tolerance through a NUCLEAR FACTOR-Y trimeric transcription factor complex in Arabidopsis

Summary Jasmonate (JA) is a well-known phytohormone essential for plant response to biotic stress. Recently, a crucial role of JA signaling in salt resistance has been highlighted; however, the specific regulatory mechanism remains largely unknown. In this study, we found that the NUCLEAR FACTOR-Y (NF-Y) subunits NF-YA1, NF-YB2, and NF-YC9 form a trimeric complex that positively regulates the expression of salinity-responsive genes. Whereas JASMONATE-ZIM DOMAIN protein8 (JAZ8) directly interacts with three subunits acting as the key repressor to suppress both the assembly of the NF-YA1-YB2-YC9 trimeric complex and the transcriptional activation activity of the complex. When plants encounter high salinity, JA levels are elevated and perceived by the CORONATINE INSENSITIVE (COI)1 receptor, leading to the degradation of JAZ8 via the 26S proteasome pathway, therefore release the activity of NF-YA1-YB2-YC9 complex, initiating the activation of salinity-responsive genes, such as MYB75, thereby enhancing salinity tolerance of plants.