Arabidopsis NAC transcription factor JUB1 regulates GA/BR metabolism and signalling
Arabidopsis NAC transcription factor JUB1 regulates GA/BR metabolism and signalling
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DOI：
10.1038/nplants.2016.13
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发表时间：
2016-03-01
期刊：
影响因子：
18
通讯作者：
Balazadeh, Salma
中科院分区：
文献类型：
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作者：
Shahnejat-Bushehri, Sara;Tarkowska, Danuse;Balazadeh, Salma
赤霉素（giberellins, GAs）和油菜素内酯（brassinosteroids, BRs）是控制植物发育和对环境信号响应的重要植物激素，其关键转录因子分别是DELLA蛋白和brassinazol - resistant1 （BZR1）。在这里，我们揭示了JUNGBRUNNEN1 （JUB1）作为拟南芥GA/BR信号传导的转录调节因子的新作用。JUB1直接抑制激素生物合成基因GA3ox1和DWARF4 (DWF4)，导致GAs和BR水平降低，导致典型的GA/BR缺乏表型，表现为下胚轴短、侏儒症、晚开花和雄性不育。JUB1还直接抑制光敏色素相互作用因子4 (PIF4)，这是一种连接激素和环境刺激的转录因子。另一方面，JUB1激活DELLA基因GA不敏感基因（GAI）和RGA-LIKE 1 （RGL1）。此外，BZR1和PIF4作为JUB1上游的直接转录抑制因子，建立了一个负反馈回路。因此，JUB1构成了一个强大的调控模块的核心，该模块触发DELLA积累，从而限制细胞伸长，同时增强抗逆性。
Gibberellins (GAs) and brassinosteroids (BRs) are important phytohormones that control plant development and responses to environmental cues by involving DELLA proteins and BRASSINAZOLE-RESISTANT1 (BZR1) respectively as key transcription factors. Here, we reveal a new role for JUNGBRUNNEN1 (JUB1) as a transcriptional regulator of GA/BR signalling in Arabidopsis thaliana. JUB1 directly represses the hormone biosynthesis genes GA3ox1 and DWARF4 (DWF4), leading to reduced levels of GAs and BRs and typical GA/BR deficiency phenotypes exhibiting short hypocotyls, dwarfism, late flowering and male sterility. JUB1 also directly represses PHYTOCHROME INTERACTING FACTOR4 (PIF4), a transcription factor connecting hormonal and environmental stimuli. On the other hand, JUB1 activates the DELLA genes GA INSENSITIVE (GAI) and RGA-LIKE 1 (RGL1). In addition, BZR1 and PIF4 act as direct transcriptional repressors upstream of JUB1, establishing a negative feedback loop. Thus, JUB1 forms the core of a robust regulatory module that triggers DELLA accumulation, thereby restricting cell elongation while concomitantly enhancing stress tolerance.