Coordinated Regulation of Hypocotyl Cell Elongation by Light and Ethylene through a Microtubule Destabilizing Protein
Coordinated Regulation of Hypocotyl Cell Elongation by Light and Ethylene through a Microtubule Destabilizing Protein
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光和乙烯通过微管不稳定蛋白协调调节下胚轴细胞伸长
DOI：
10.1104/pp.17.01109
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发表时间：
2018-01-01
期刊：
影响因子：
7.4
通讯作者：
Mao, Tonglin
中科院分区：
文献类型：
--
作者：
Ma, Qianqian;Wang, Xiaohong;Mao, Tonglin
下胚轴细胞伸长的精确调节对于植物生长和存活至关重要。光通过降解转录因子光敏色素相互作用因子 3 (PIF3) 来抑制下胚轴伸长，而植物激素乙烯则通过激活 PIF3 来促进下胚轴伸长。然而，这两条途径如何协调下游效应器以介导下胚轴伸长的潜在机制尚不清楚。在这项研究中，我们发现了新型微管不稳定蛋白 60 (MDP60)，它在拟南芥 (Arabidopsis thaliana) 的下胚轴细胞伸长中发挥着积极作用；这种作用是通过 PIF3 介导的。乙烯信号通过 PIF3 与 MDP60 启动子结合上调 MDP60 表达。 MDP60 功能丧失突变体表现出更短的下胚轴，而与对照相比，MDP60 过表达在光照下生长时显着促进下胚轴细胞伸长。 MDP60 蛋白在体外和体内与微管结合。 mdp60 突变细胞和 MDP60 过表达幼苗中的皮质微管组织显着破坏。这些发现表明 MDP60 是下胚轴细胞伸长的重要介质。这项研究揭示了光和乙烯信号传导协调 MDP60 表达，通过改变拟南芥皮质微管来调节下胚轴细胞伸长的机制。
Precise regulation of hypocotyl cell elongation is essential for plant growth and survival. Light suppresses hypocotyl elongation by degrading transcription factor phytochrome-interacting factor 3 (PIF3), whereas the phytohormone ethylene promotes hypocotyl elongation by activating PIF3. However, the underlying mechanisms regarding how these two pathways coordinate downstream effectors to mediate hypocotyl elongation are largely unclear. In this study, we identified the novel Microtubule-Destabilizing Protein 60 (MDP60), which plays a positive role in hypocotyl cell elongation in Arabidopsis (Arabidopsis thaliana); this effect is mediated through PIF3. Ethylene signaling up-regulates MDP60 expression via PIF3 binding to the MDP60 promoter. MDP60 loss-of-function mutants exhibit much shorter hypocotyls, whereas MDP60 overexpression significantly promotes hypocotyl cell elongation when grown in light compared to the control. MDP60 protein binds to microtubules in vitro and in vivo. The organization of cortical microtubules was significantly disrupted in mdp60 mutant cells and MDP60-overexpressing seedlings. These findings indicate that MDP60 is an important mediator of hypocotyl cell elongation. This study reveals a mechanism in which light and ethylene signaling coordinate MDP60 expression to modulate hypocotyl cell elongation by altering cortical microtubules in Arabidopsis.