COLD REGULATED 27 and 28 are targets of CONSTITUTIVELY PHOTOMORPHOGENIC 1 and negatively affect phytochrome B signalling
COLD REGULATED 27 and 28 are targets of CONSTITUTIVELY PHOTOMORPHOGENIC 1 and negatively affect phytochrome B signalling
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DOI：
10.1111/tpj.14979
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发表时间：
2020-09-27
期刊：
影响因子：
7.2
通讯作者：
Hiltbrunner, Andreas
中科院分区：
文献类型：
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作者：
Kahle, Nikolai;Sheerin, David J.;Hiltbrunner, Andreas
光敏色素是植物中的红光/远红光受体，参与植物生长发育的调节。光敏色素可以感知光环境，并有助于测量日长；因此，它们允许植物对周围环境的变化做出反应和适应。两条特征明确的信号通路作用于光敏色素下游，并将光感知与基因表达的调节联系起来。组成光形态发生蛋白1/PhyA-105抑制子(COP1/SPA)的E3泛素连接酶复合体和光敏色素相互作用因子(PIF)是这些途径的关键成分，它们在黑暗中抑制光反应。在光照生长的幼苗中，光敏色素抑制COP1/SPA和PIF活性，从而促进光信号传递。在酵母双杂交筛选与光激活光敏色素结合的蛋白质时，我们发现了冷调节基因27(COR27)。COR27及其同系物COR28与种子植物中两种主要的光敏色素PhyA和PhyB结合。关于COR27和COR28在调节耐寒性、开花和生物钟方面的功能，以前已经进行了描述。在这里，我们发现COR27和COR28在蓝光、远红光，特别是红光下抑制幼苗的早期发育。COR27和COR28含有一个保守的Val-Pro(VP)-肽基序，它介导与COP1/SPA复合体的结合。COR27和COR28是COP1/SPA降解的靶点，VP-肽基序中VP到AA氨基酸取代的突变版本是稳定的。总体而言，我们的数据表明，COR27和COR28在光中积累，但在幼苗发育早期作为光信号的负调节因子，从而防止对光的夸大反应。
Phytochromes are red/far-red light receptors in plants involved in the regulation of growth and development. Phytochromes can sense the light environment and contribute to measuring day length; thereby, they allow plants to respond and adapt to changes in the ambient environment. Two well-characterized signalling pathways act downstream of phytochromes and link light perception to the regulation of gene expression. The CONSTITUTIVELY PHOTOMORPHOGENIC 1/SUPPRESSOR OF PHYA-105 (COP1/SPA) E3 ubiquitin ligase complex and the PHYTOCHROME INTERACTING FACTORs (PIFs) are key components of these pathways and repress light responses in the dark. In light-grown seedlings, phytochromes inhibit COP1/SPA and PIF activity and thereby promote light signalling. In a yeast-two-hybrid screen for proteins binding to light-activated phytochromes, we identified COLD-REGULATED GENE 27 (COR27). COR27 and its homologue COR28 bind to phyA and phyB, the two primary phytochromes in seed plants. COR27 and COR28 have been described previously with regard to a function in the regulation of freezing tolerance, flowering and the circadian clock. Here, we show that COR27 and COR28 repress early seedling development in blue, far-red and in particular red light. COR27 and COR28 contain a conserved Val-Pro (VP)-peptide motif, which mediates binding to the COP1/SPA complex. COR27 and COR28 are targeted for degradation by COP1/SPA and mutant versions with a VP to AA amino acid substitution in the VP-peptide motif are stabilized. Overall, our data suggest that COR27 and COR28 accumulate in light but act as negative regulators of light signalling during early seedling development, thereby preventing an exaggerated response to light.