BIL1-mediated MP phosphorylation integrates PXY and cytokinin signalling in secondary growth
BIL1-mediated MP phosphorylation integrates PXY and cytokinin signalling in secondary growth
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DOI：
10.1038/s41477-018-0180-3
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发表时间：
2018-08-01
期刊：
影响因子：
18
通讯作者：
Hwang, Ildoo
中科院分区：
文献类型：
--
作者：
Han, Soeun;Cho, Hyunwoo;Hwang, Ildoo
植物维管形成层的增殖对维管组织的产生和机械强度至关重要。植物激素和移动肽是次生生长过程中维管形成层活性的关键调节因子；然而，它们协调行动背后的信号串扰在很大程度上是未知的。本研究揭示糖原合成酶激酶3 - BIN2-LIKE 1 （BIL1）在次生生长过程中将韧皮部插接木质部/管状细胞分化抑制因子（TDIF）受体（PXY/TDR）模块整合到单细胞/生长素反应因子5 （MP/ARF5）转录因子的作用中。bil1介导的MP/ARF5磷酸化增强了其对维管形成层活性的负面影响，从而上调细胞分裂素信号传导的负调控因子ARABIDOPSIS RESPONSE REGULATOR 7 （ARR7）和ARRI5。PXY/TDR抑制BIL1活性，从而减弱MP/ARF5对ARR7和ARR15表达的影响，从而增加维管形成层活性。总之，这些结果表明，BIL1是连接肽信号和生长素-细胞分裂素信号以维持形成层活性的关键介质。
Vascular cambium proliferation in plants is crucial for the generation of vascular tissues and for mechanical strength. Phytohormones and mobile peptides are key regulators of vascular cambial activity during secondary growth; however, the signalling cross-talk underlying their coordinated action is largely unknown. Here, we reveal that BIN2-LIKE 1 (BIL1), a glycogen synthase kinase 3, integrates the PHLOEM INTERCALATED WITH XYLEM/tracheary element differentiation inhibitory factor (TDIF) RECEPTOR (PXY/TDR) module into MONOPTEROS/AUXIN RESPONSE FACTOR 5 (MP/ARF5) transcription factor action during secondary growth. BIL1-mediated phosphorylation of MP/ARF5 enhances its negative effect on vascular cambial activity, which upregulates the negative regulators of cytokinin signalling ARABIDOPSIS RESPONSE REGULATOR 7 (ARR7) and ARRI5. PXY/TDR inhibits BIL1 activity, which attenuates the effect of MP/ARF5 on ARR7 and ARR15 expression, thus increasing vascular cambial activity. Together, these results suggest that BIL1 is a key mediator that links peptide signalling with auxin-cytokinin signalling for the maintenance of cambial activity.