Key message

We found that mutations in a Ca ²⁺ -permeable mechanosensitive channel MCA1, an ethylene-regulated microtubule-associated protein WDL5, and a versatile co-receptor BAK1 affect root growth response to mechanical stress.

Abstract

Plant root tips exposed to mechanical impedance show a temporal reduction in the elongation growth. The process involves a transient Ca²⁺ increase in the cytoplasm followed by ethylene signaling. To dissect the molecular mechanisms underlying this response, we examined the root growth of a series of Arabidopsis mutants with potentially altered response to mechanical stress after transfer from vertical to horizontal plates that were covered by dialysis membrane as an impedance. Among the plant hormone-response mutants tested, the ethylene-insensitive mutant ein3 was confirmed to show no growth reduction after the transfer. The root growth reduction was attenuated in a mutant of MCA1 encoding a Ca²⁺-permeable mechanosensitive channel and that of WDL5 encoding an ethylene-regulated microtubule-associated protein. We also found that the growth reduction was enhanced in a mutant of BAK1 encoding a co-receptor that pairs with numerous leucine-rich repeat receptor kinases to modulate growth and immunity. These results suggest the root growth reduction in response to mechanical stress involves ethylene-mediated microtubule reorganization and also transmembrane receptor-mediated signal transduction.

中文翻译：

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响应机械应力的根生长减少涉及拟南芥乙烯介导的微管重组和跨膜受体介导的信号转导

关键信息

我们发现 Ca ²⁺ 可渗透机械敏感通道 MCA1、乙烯调节的微管相关蛋白 WDL5 和多功能共受体 BAK1 中的突变影响根生长对机械应力的反应。

抽象的

暴露于机械阻抗的植物根尖显示伸长生长的时间减少。该过程涉及细胞质中Ca ²⁺的瞬时增加，然后是乙烯信号传导。为了剖析这种反应背后的分子机制，我们检查了一系列拟南芥突变体的根系生长，这些突变体在从被透析膜覆盖作为阻抗的垂直板转移到水平板后对机械应力的反应可能发生改变。在测试的植物激素反应突变体中，乙烯不敏感突变体ein3被证实在转移后没有显示出生长减少。在编码 Ca ^2+的MCA1突变体中根生长减少减弱-可渗透的机械敏感通道和编码乙烯调节的微管相关蛋白的WDL5通道。我们还发现，BAK1突变体的生长减少增强了，该突变体编码一种与许多富含亮氨酸的重复受体激酶配对以调节生长和免疫的共受体。这些结果表明响应机械应力的根生长减少涉及乙烯介导的微管重组以及跨膜受体介导的信号转导。