ROS homeostasis mediated by MPK4 and SUMM2 determines synergid cell death

第一作者：Ronny Völz

第一单位：首尔国立大学

通讯作者：Yong-Hwan Lee

 Abstarct 

背景回顾：Sexual plant reproduction depends on the attraction of sperm-cell delivering pollen tubes (PT) by two synergids, followed by their programmed cell death (PCD) in Arabidopsis. Disruption of the mitogen-activated protein kinase 4 (MPK4) by pathogenic effectors activates the resistance protein (R) SUMM2-mediated immunity and cell death. 

在拟南芥中，有性生殖依赖于两个助细胞对传递花粉管的精子细胞的吸引，以及随后的程序性细胞死亡。通过病原菌效应物扰乱MPK4，能够激活抗性蛋白SUMM2介导的植物免疫和细胞死亡。

主要研究：Here we show that synergid preservation and reactive oxygen species (ROS) homeostasis are intimately linked and maintained by MPK4. 

本文中，作者发现助细胞的保存与活性氧物质（ROS）的动态平衡密切相关，并且是由MPK4所维持。

结果1-单突及拯救：In mpk4, ROS levels are increased and synergids prematurely undergo PCD before PT-reception. However, ROS scavengers and the disruption of SUMM2, in mpk4, restore ROS homeostasis, synergid maintenance and PT perception, demonstrating that the guardian of MPK4, SUMM2, triggers synergid-PCD. 

在mpk4突变体中，ROS水平升高，助细胞在接受花粉管之前就已经经历了程序性细胞死亡。但是，通过清除mpk4突变体中的ROS以及扰乱SUMM2，能够恢复ROS的内稳态、助细胞的维持及其对花粉管的感知，表明SUMM2诱导了助细胞的程序性细胞死亡。

结果2-双突：In mpk4/summ2, PTs show a feronia-like overgrowth phenotype. 

在mpk4/summ2突变体中，花粉管表现出类似feronia突变体的过度生长表型。

结论：Our results show that immunity-associated PCD and synergid cell death during plant reproduction are regulated by MPK4 underscoring an underlying molecular mechanism for the suppression of plant reproduction during systemic R-mediated immunity.

本文的研究结果表明，在植物繁殖过程中与免疫相关的程序性细胞死亡和助细胞死亡受到MPK4的调节；揭示了一个在系统性R基因介导的免疫过程中，抑制植物繁殖的潜在分子机制。

** Yong-Hwan Lee **

doi: https://doi.org/10.1038/s41467-022-29373-7

Journal: Nature Communications

Published date: April 01, 2022