Brassinosteroid-Activated BRI1-EMS-SUPPRESSOR 1 Inhibits Flavonoid Biosynthesis and Coordinates Growth and UV-B Stress Responses in Plants

编号 040025805

推送时间 20200928

研究领域 森林培育 

年份 2020 

类型 期刊 

语种 英语

标题 Brassinosteroid-Activated BRI1-EMS-SUPPRESSOR 1 Inhibits Flavonoid Biosynthesis and Coordinates Growth and UV-B Stress Responses in Plants

来源期刊 The Plant Cell

期 第258期

发表时间 20200813

关键词 UV-B light;  BES1;  brassinosteroids;  flavonoids; 

摘要 Ultraviolet B (UV-B) light is a potential stress factor in plants, but how plants coordinate growth and UV-B stress responses is not well understood. Here we report that brassinosteroid (BR) signaling inhibits UV-B stress responses in Arabidopsis thaliana and various crops by controlling flavonol biosynthesis. We further demonstrate that BRI1-EMS-SUPPRESSOR 1 (BES1) mediates the tradeoff between plant growth and UV-B defense responses. BES1, a master transcription factor involved in BR signaling, represses the expression of transcription factor genes MYB11, MYB12, and MYB111, which activate flavonol biosynthesis. BES1 directly binds to the promoters of these MYBs in a BR-enhanced manner to repress their expression, thereby reducing flavonol accumulation. However, exposure to broad-band UV-B, primarily low-wavelength high-energy UV-B light, down-regulates BES1 expression, thus promoting flavonol accumulation. These findings demonstrate that BR-activated BES1 not only promotes growth but also inhibits flavonoid biosynthesis. UV-B stress suppresses the expression of BES1 to allocate energy to flavonoid biosynthesis and UV-B stress responses, allowing plants to switch from growth to UV-B stress responses in a timely manner.

服务人员 孙小满

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