High Ambient Temperature Represses Anthocyanin Biosynthesis through Degradation of HY5

Frontiers in Plant Science

Geonhee Hwang¹  Seulgi Lee¹  Sara Kim¹  Jungmook Kim¹  Thom Thi Nguyen¹  Eunkyoo Oh¹  Inyup Paik²  Jia-Ying Zhu³ 

[1] Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, South Korea;Department of Molecular Biosciences, The Institute for Cellular and Molecular Biology, University of Texas, Austin, TX, United States;Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States;

关键词: Arabidopsis;    high temperature stress;    anthocyanin;    HY5;    flavonoid;    gene expression;   

DOI  :  10.3389/fpls.2017.01787

来源: DOAJ

【 摘 要 】

Anthocyanins are flavonoid compounds that protect plant tissues from many environmental stresses including high light irradiance, freezing temperatures, and pathogen infection. Regulation of anthocyanin biosynthesis is intimately associated with environmental changes to enhance plant survival under stressful environmental conditions. Various factors, such as UV, visible light, cold, osmotic stress, and pathogen infection, can induce anthocyanin biosynthesis. In contrast, high temperatures are known to reduce anthocyanin accumulation in many plant species, even drastically in the skin of fruits such as grape berries and apples. However, the mechanisms by which high temperatures regulate anthocyanin biosynthesis in Arabidopsis thaliana remain largely unknown. Here, we show that high ambient temperatures repress anthocyanin biosynthesis through the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) and the positive regulator of anthocyanin biosynthesis ELONGATED HYPOCOTYL5 (HY5). We show that an increase in ambient temperature decreases expression of genes required in both the early and late steps of the anthocyanin biosynthesis pathway in Arabidopsis seedlings. As a result, seedlings grown at a high temperature (28°C) accumulate less anthocyanin pigment than those grown at a low temperature (17°C). We further show that high temperature induces the degradation of the HY5 protein in a COP1 activity-dependent manner. In agreement with this finding, anthocyanin biosynthesis and accumulation do not respond to ambient temperature changes in cop1 and hy5 mutant plants. The degradation of HY5 derepresses the expression of MYBL2, which partially mediates the high temperature repression of anthocyanin biosynthesis. Overall, our study demonstrates that high ambient temperatures repress anthocyanin biosynthesis through a COP1-HY5 signaling module.

【 授权许可】

Unknown