Journal Article

COP1 conveys warm temperature information to hypocotyl thermomorphogenesis

Jun-Ho Ha, Young-Joon Park, Hyo-Jun Lee, Jae Young Kim, Chung-Mo Park

2017

Overview

Plants adjust their architecture to optimize growth and reproductive success under changing climates. Hypocotyl elongation is a pivotal morphogenic trait that is profoundly influenced by light and temperature conditions. While hypocotyl photomorphogenesis has been well characterized at the molecular level, molecular mechanisms underlying hypocotyl thermomorphogenesis remains elusive. Here, we demonstrate that the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) conveys warm temperature signals to hypocotyl thermomorphogenesis. To investigate the roles of COP1 and its target ELONGATED HYPOCOTYL 5 (HY5) during hypocotyl thermomorphogenesis, we employed Arabidopsis mutants that are defective in their genes. Transgenic plants overexpressing the genes were also produced. We examined hypocotyl growth and thermoresponsive turnover rate of HY5 protein at warm temperatures under both light and dark conditions. Elevated temperatures trigger the nuclear import of COP1, thereby alleviating the suppression of hypocotyl growth by HY5. While the thermal induction of hypocotyl growth is circadian-gated, the degradation of HY5 by COP1 is uncoupled from light responses and timing information. We propose that thermal activation of COP1 enables coincidence between warm temperature signaling and circadian rhythms, which allows plants to gate hypocotyl thermomorphogenesis at the most profitable time at warm temperatures.

• Publisher: New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: Activation / Arabidopsis / Arabidopsis - genetics / Arabidopsis - metabolism / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis Proteins - physiology / Architecture / Breeding success / circadian clock / Circadian rhythm / Circadian rhythms / Climate / Climate change / CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) / Conveying / Degradation / ELONGATED HYPOCOTYL 5 (HY5) / Elongation / Gene Expression Regulation, Plant / gene overexpression / Genes / Growth / High temperature / Hypocotyl - growth & development / Hypocotyl - metabolism / Hypocotyl - physiology / hypocotyl elongation / hypocotyls / Light / Light effects / Molecular modelling / mutants / Nuclear transport / Photomorphogenesis / physiological transport / Protein turnover / Proteins / Reproduction / reproductive success / Seedlings - growth & development / Signal Transduction / Temperature / Temperature effects / thermomorphogenesis / Time measurement / Transgenic plants / Turnover rate / Ubiquitin-protein ligase