The GSK3-like Kinase BIN2 Is a Molecular Switch between the Salt Stress Response and Growth Recovery in Arabidopsis thaliana

• Published in: Developmental cell Vol. 55; no. 3; pp. 367 - 380.e6
• Main Authors: Li, Jianfang, Zhou, Huapeng, Zhang, Yan, Li, Zhen, Yang, Yongqing, Guo, Yan
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.11.2020
• Subjects: Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; BIN2; BR signal; calcium signal; Gene Expression Regulation, Plant; Glycogen Synthase Kinase 3 - metabolism; growth recovery; Homeostasis; Models, Biological; Phosphorylation; Phosphothreonine - metabolism; Protein Binding; Protein Kinases - genetics; Protein Kinases - metabolism; Salt Stress; salt stress response; SOS pathway; Arabidopsis thaliana; salt stress response; BIN2; SOS pathway; BR signal; growth recovery; calcium signal
• ISSN: 1534-5807; 1878-1551; 1878-1551
• DOI: 10.1016/j.devcel.2020.08.005

Plant stress responses involve dynamic growth regulation. Growth is restricted in harsh environmental conditions and is rapidly restored when conditions improve. Here, we identified BIN2, a glycogen synthase kinase 3 (GSK3)-like kinase, as a molecular switch in the transition to robust growth after salt stress in Arabidopsis thaliana. In the rapid recovery phase after salt stress, the calcium sensors SOS3 and SCaBP8 perceive a calcium signal and promote BIN2 localization to the plasma membrane to repress the salt stress response, and BIN2 inhibits SOS2 activity and enhances growth by releasing BZR1/BES1 transcriptional activity. The expression of stress- and brassinosteroid-responsive genes is coordinately regulated during this process. bin2-3bil1 and bin2-3bil2 mutants defective in BIN2 and its homologs BIL1 and BIL2, respectively, are hyposensitive to salt stress. Our study suggests that salt signaling modulates the subcellular localization and interactions of BIN2. By phosphorylating different substrates, BIN2 regulates the salt stress response and growth recovery. [Display omitted] •BIN2 phosphorylates and inhibits SOS2 to negatively regulate salt stress tolerance•SOS3/SCaBP8 promotes BIN2 plasma membrane localization during recovery after salt stress•SOS3/SCaBP8-BIN2 module inhibits SOS2 activity and releases BZR1/BES1 activity•BIN2 maintains plant homeostasis by modulating salt stress response and growth Plants have to adjust their growth to withstand environmental stress. Plant growth and stress responses thus need to be balanced. Li et al. show that GSK3-like kinase BIN2 cooperates with calcium sensors SOS3 and SCaBP8 to fine-tune the SOS pathway-mediated salt stress response and BR-regulated plant growth.