Phytochrome-interacting transcription factors PIF4 and PIF5 induce leaf senescence in Arabidopsis
Phytochrome-interacting transcription factors PIF4 and PIF5 induce leaf senescence in Arabidopsis
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DOI：
10.1038/ncomms5636
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发表时间：
2014-08-01
影响因子：
16.6
通讯作者：
Choi, Giltsu
中科院分区：
文献类型：
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作者：
Sakuraba, Yasuhito;Jeong, Jinkil;Choi, Giltsu
植物开始衰老以脱落光合效率低下的叶子。光剥夺诱导叶片衰老，这涉及大量的转录重编程，以拆除细胞成分和重新动员营养。在黑暗中，间歇性的红光脉冲可以抑制衰老，可能是通过光敏色素。然而，从光感知到衰老抑制的信号转导的精确分子机制仍然是难以捉摸的。在这里，我们表明，在拟南芥中，黑暗诱导衰老需要光敏色素相互作用的转录因子PIF 4和PIF 5（PIF 4/PIF 5）。ELF 3和光敏色素B分别通过在转录和翻译后水平抑制PIF 4/PIF 5来抑制衰老。PIF 4/PIF 5通过直接激活EIN 3、ABI 5和EEL的表达，在两种衰老促进激素乙烯和脱落酸的信号传导途径中起作用。反过来，PIF 4、PIF 5、EIN 3、ABI 5和EEL直接激活主要的衰老促进NAC转录因子ORESARA 1的表达，从而形成多个连贯的前馈环。我们的研究结果揭示了经典的光信号如何连接到拟南芥衰老。
Plants initiate senescence to shed photosynthetically inefficient leaves. Light deprivation induces leaf senescence, which involves massive transcriptional reprogramming to dismantle cellular components and remobilize nutrients. In darkness, intermittent pulses of red light can inhibit senescence, likely via phytochromes. However, the precise molecular mechanisms transducing the signals from light perception to the inhibition of senescence remain elusive. Here, we show that in Arabidopsis, dark-induced senescence requires phytochrome-interacting transcription factors PIF4 and PIF5 (PIF4/PIF5). ELF3 and phytochrome B inhibit senescence by repressing PIF4/PIF5 at the transcriptional and post-translational levels, respectively. PIF4/PIF5 act in the signalling pathways of two senescence-promoting hormones, ethylene and abscisic acid, by directly activating expression of EIN3, ABI5 and EEL. In turn, PIF4, PIF5, EIN3, ABI5 and EEL directly activate the expression of the major senescence-promoting NAC transcription factor ORESARA1, thus forming multiple, coherent feed-forward loops. Our results reveal how classical light signalling connects to senescence in Arabidopsis.