Jasmonate inhibits COP1 activity to suppress hypocotyl elongation and promote cotyledon opening in etiolated Arabidopsis seedlings. (29th April 2017)

• Record Type: Journal Article
• Authors: Zheng, Yuyu; Cui, Xuefei; Su, Liang; Fang, Shuang; Chu, Jinfang; Gong, Qingqiu; Yang, Jianping; Zhu, Ziqiang
• Is Part Of: Plant journal. Volume 90:Number 6(2017)
• Page Start: 1144
• Page End: 1155
• Publication Date: 2017-04-29
• Subjects: CONSTITUTIVE PHOTOMORPHOGENIC 1 -- ELONGATED HYPOCOTYL 5 -- protein degradation -- jasmonate -- skotomorphogenesis -- photomorphogenesis -- Arabidopsis; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.13539
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: A germinating seedling undergoes skotomorphogenesis to emerge from the soil and reach for light. During this phase, the cotyledons are closed, and the hypocotyl elongates. Upon exposure to light, the seedling rapidly switches to photomorphogenesis by opening its cotyledons and suppressing hypocotyl elongation. The E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) is critical for maintaining skotomorphogenesis. Here, we report that jasmonate (JA) suppresses hypocotyl elongation and stimulates cotyledon opening in etiolated seedlings, partially phenocopying cop1 mutants in the dark. We also find that JA stabilizes several COP1‐targeted transcription factors in a COP1‐dependent manner. RNA‐seq analysis further defines a JA‐light co‐modulated and cop1 ‐dependent transcriptome, which is enriched for auxin‐responsive genes and genes participating in cell wall modification. JA suppresses COP1 activity through at least two distinct mechanisms: decreasing COP1 protein accumulation in the nucleus; and reducing the physical interaction between COP1 and its activator, SUPPRESSOR OF PHYTOCHROME A‐105 1 (SPA1). Our work reveals that JA suppresses COP1 activity to stabilize COP1 targets, thereby inhibiting hypocotyl elongation and stimulating cotyledon unfolding in etiolated Arabidopsis seedlings. Significance Statement: Jasmonate stabilizes COP1‐targeted transcription factors and elicits a proportion of the light‐responsive transcriptome in etiolated Arabidopsis seedlings to suppress hypocotyl elongation and promote cotyledon unfolding.