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Development Cell：UVR8调控拟南芥的光形态建成

已有 5328 次阅读 2018-2-7 08:47 |个人分类:每日摘要|系统分类:论文交流

UVR8 Interacts with BES1 and BIM1 to Regulate Transcription and Photomorphogenesis in Arabidopsis

First author: Tong Liang; Affiliations: Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (中国科学院植物生理生态研究所): Shanghai, China

Corresponding author: Hongtao Liu (刘宏涛)

UV-B light (UV-B radiation) is known to inhibit plant growth, but the mechanism is not well understood. UVR8 (UV RESISTANCE LOCUS 8) is a UV-B light photoreceptor (光感受器) that mediates UV-B light responses in plants. We report here that UV-B inhibits plant growth by repressing plant steroid hormone (类固醇激素) brassinosteroid (BR; 油菜素甾醇)-promoted plant growth. UVR8 physically interacts with the functional dephosphorylated (去磷酸化) BES1 (BRI1-EMS-SUPPRESSOR1) and BIM1 (BES1-INTERACTING MYC-LIKE 1) transcription factors that mediate BR-regulated gene expression and plant growth to inhibit their activities. Genome-wide gene expression analysis defined a BES1-dependent UV-B-regulated transcriptome, which is enriched with genes involved in cell elongation and plant growth. We further showed that UV-B-activated and nucleus-localized UVR8 inhibited the DNA-binding activities of BES1/BIM1 to directly regulate transcription of growth-related genes. Our results therefore establish that UVR8-BES1/BIM1 interaction represents an early photoreceptor signaling mechanism in plants and serves as an important module integrating light and BR signaling.

紫外线UV-B会抑制植物的生长，但其发挥作用的机制还一直不清楚。紫外线抗性位点UVR8是UV-B的光感受器，其介导植物中的紫外线辐射响应。植物类固醇激素油菜素甾醇BR会植物生长，本文报道了UV-B会通过抑制这个过程来发挥其抑制植物的生长的作用。UVR8会与具有功能的去磷酸化的BES1和BIM1转录因子互作，这两个转录因子会介导BR调控的基因表达和植物生长，UVR8通过抑制这两者的活性来发挥作用。基因组范围的基因表达分析鉴定了一个BES1依赖性的UV-B调控的转录组，显著富集在一些参与细胞延长和植物生长方面的基因上。作者进一步的分析显示UV-B激活的、定位于核的UVR8会抑制BES1/BIM1的DNA结合活性，从而直接调控生长相关基因的转录。本文的结果显示UVR8-BES1/BIM1之间的互作是植物早期光感受的信号分子途径，该研究为整合植物中的光照和BR信号转导模块提供了重要的提示。

通讯：刘宏涛 (http://www.sippe.ac.cn/cp1-8_PI.asp?id=24)