Brassinosteroid signaling regulator BIM1 integrates brassinolide and jasmonic acid signaling during cold tolerance in apple

• DOI: 10.1093/plphys/kiad371
• Publication Date: 2023-07-01T20:48:45Z
• Authors: Jian-Ping An; Zhi-Ying Liu; Xiao-Wei Zhang; Da-Ru Wang; Fanchang Zeng; Chun-Xiang You; Yuepeng Han
• Keywords: Jasmonic acid; Brassinosteroid; Crosstalk; Brassinolide

Although brassinolide (BR) and jasmonic acid (JA) play essential roles in the regulation of cold stress responses, molecular basis their crosstalk remains elusive. Here, we show a key component BR signaling apple (Malus × domestica), INSENSITIVE1 (BRI1)-EMS-SUPPRESSOR1 (BES1)-INTERACTING MYC-LIKE PROTEIN1 (MdBIM1), increases tolerance by directly activating expression C-REPEAT BINDING FACTOR1 (MdCBF1) forming complex with FACTOR2 (MdCBF2) to enhance MdCBF2-activated transcription cold-responsive genes. Two repressors JA signaling, JAZMONATE ZIM-DOMAIN1 (MdJAZ1) ZIM-DOMAIN2 (MdJAZ2), interact MdBIM1 integrate under stress. MdJAZ1 MdJAZ2 reduce MdBIM1-promoted attenuating transcriptional activation MdCBF1 interfering formation MdBIM1-MdCBF2 complex. Furthermore, E3 ubiquitin ligase ARABIDOPSIS TÓXICOS en LEVADURA73 (MdATL73) decreases targeting for ubiquitination degradation. Our results not only reveal between mediated JAZ-BIM1-CBF module but also provide insights into posttranslational regulatory mechanism signaling.