COP1 SUPPRESSOR 6 represses the PIF4 and PIF5 action to promote light‐inhibited hypocotyl growth. Issue 11 (26th September 2022)

• Record Type: Journal Article
• Authors: Lan, Hongxia; Heng, Yueqin; Li, Jian; Zhang, Mengdi; Bian, Yeting; Chu, Li; Jiang, Yan; Wang, Xuncheng; Xu, Dongqing; Deng, Xing Wang
• Is Part Of: Journal of integrative plant biology. Volume 64:Issue 11(2022)
• Page Start: 2097
• Page End: 2110
• Publication Date: 2022-09-26
• Subjects: COP1 -- CSU6 -- light signaling -- photomorphogenesis -- PIF4 -- PIF5; Plants -- Periodicals; Plants -- China -- Periodicals; Electronic journals; 580.5
• DOI: 10.1111/jipb.13350
• Languages: English
• ISSNs: 1672-9072

Abstract

ABSTRACT: Light signaling precisely controls photomorphogenic development in plants. PHYTOCHROME INTERACTING FACTOR 4 and 5 (PIF4 and PIF5) play critical roles in the regulation of this developmental process. In this study, we report CONSTITUTIVELY PHOTOMORPHOGENIC 1 SUPPRESSOR 6 (CSU6) functions as a key regulator of light signaling. Loss of CSU6 function largely rescues the cop1‐6 constitutively photomorphogenic phenotype. CSU6 promotes hypocotyl growth in the dark, but inhibits hypocotyl elongation in the light. CSU6 not only associates with the promoter regions of PIF4 and PIF5 to inhibit their expression in the morning, but also directly interacts with both PIF4 and PIF5 to repress their transcriptional activation activity. CSU6 negatively controls a group of PIF4‐ and PIF5‐regulated gene expressions. Mutations in PIF4 and/or PIF5 are epistatic to the loss of CSU6, suggesting that CSU6 acts upstream of PIF4 and PIF5 . Taken together, CSU6 promotes light‐inhibited hypocotyl elongation by negatively regulating PIF4 and PIF5 transcription and biochemical activity. Abstract : Light is one of the most important environmental factors controlling seedling development and COP1 SUPPRESSOR 6 functions as a transcriptional repressor in repressing PHYTOCHROME INTERACTING FACTOR 4 and 5 transcription and biochemical activity to promote light‐inhibited hypocotyl growth.