The HB40-JUB1 transcriptional regulatory network controls gibberellin homeostasis in Arabidopsis

编号 040032404

推送时间 20220103

研究领域 森林培育 

年份 2022 

类型 期刊 

语种 英语

标题 The HB40-JUB1 transcriptional regulatory network controls gibberellin homeostasis in Arabidopsis

来源期刊 Molecular Plant

期 第324期

发表时间 20211029

关键词 Arabidopsis；growth；gibberellin；homeostasis；transcription factor；HB40;  JUB1；GA
2-oxidase；DELLA proteins; 

摘要 The phytohormones gibberellins (GAs) play fundamental roles in almost every aspect of plant growth and development. Although there is good knowledge about GA biosynthetic and signaling pathways, factors contributing to the mechanisms homeostatically controlling GA levels remain largely unclear. Here, we demonstrate that homeobox transcription factor HB40 of the HD-Zip family in Arabidopsis thaliana regulates GA content at two additive control levels. We show that HB40 expression is induced by GA and in turn reduces the levels of endogenous bioactive GAs by a simultaneous reduction of GA biosynthesis and increased GA deactivation. Hence, HB40 overexpression leads to typical GA-deficiency traits, such as small rosettes, reduced plant height, delayed flowering, and male sterility. In contrast, a loss-of-function hb40 mutation enhances GA-controlled growth. Genome-wide RNA-sequencing combined with molecular-genetic analyses revealed that HB40 directly activates transcription of JUNGBRUNNEN1 (JUB1), a key TF repressing growth by suppressing GA biosynthesis and signaling. HB40 also activates genes encoding GA 2-oxidases (GA2oxs) which are major GA catabolic enzymes. The effect of HB40 is ultimately mediated through induction of nuclear growth-repressing DELLA proteins. Our results thus uncover an important role of the HB40/JUB1/GA2ox/DELLA regulatory network in controlling GA homeostasis during plant growth.

服务人员 孙小满

服务院士 尹伟伦

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