The transcriptional regulator BBX24 impairs DELLA activity to promote shade avoidance in Arabidopsis thaliana
The transcriptional regulator BBX24 impairs DELLA activity to promote shade avoidance in Arabidopsis thaliana
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DOI：
10.1038/ncomms7202
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发表时间：
2015-02-01
影响因子：
16.6
通讯作者：
Botto, Javier F.
中科院分区：
文献类型：
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作者：
Crocco, Carlos D.;Locascio, Antonella;Botto, Javier F.
为了响应树冠遮荫，植物营养结构伸长以获得光照。然而，机制，使塑料转录响应冠层遮荫光尚未完全阐明。在这里，我们建议，PIF4，在遮荫信号网络中的关键转录因子的活性，是由BBX24转录调节因子和DELLA蛋白，这是赤霉素（GA）信号通路的负调节因子之间的相互作用调制。我们表明，GA相关的目标是丰富的基因响应BBX24在阴影下，bbx24突变体的阴影响应缺陷被拯救的GA治疗，促进DELLA降解。BBX24与DELLA蛋白物理相互作用，并消除DELLA介导的PIF4活性抑制。拟议的分子机制提供了一个关键的转录因子，可能证明特别相关的波动光照条件下的活性的可逆调节。
In response to canopy shade, plant vegetative structures elongate to gain access to light. However, the mechanism that allows a plastic transcriptional response to canopy shade light is not fully elucidated. Here we propose that the activity of PIF4, a key transcription factor in the shade signalling network, is modulated by the interplay between the BBX24 transcriptional regulator and DELLA proteins, which are negative regulators of the gibberellin (GA) signalling pathway. We show that GA-related targets are enriched among genes responsive to BBX24 under shade and that the shade-response defect in bbx24 mutants is rescued by a GA treatment that promotes DELLA degradation. BBX24 physically interacts with DELLA proteins and alleviates DELLA-mediated repression of PIF4 activity. The proposed molecular mechanism provides reversible regulation of the activity of a key transcription factor that may prove especially relevant under fluctuating light conditions.