||
第一作者:Pengxue Li
第一单位:福建农林大学
通讯作者:Shuang Wu
Abstract
大背景: The precise regulation of asymmetric cell division (ACD) is essential for plant organogenesis.
小背景: In Arabidopsis roots, SHORT‐ROOT (SHR) functions to promote periclinal division in cortex/endodermis initials which generates the ground tissue patterning.
提出问题: Despite multiple downstream transcription factors and interplaying hormone pathways have been reported, the cellular mechanism that affects SHR mediated periclinal division is still largely unclear.
主要发现:Here, we found that SHR could substantially elevate reactive oxygen species (ROS) level in Arabidopsis roots by activating respiratory burst oxidase homologues (RBOHs).
结果-H2O2:Among the ROS products, hydrogen peroxide (H2O2) rather than superoxide (O2‐) played a critical role in SHR mediated periclinal division. Scavenging H2O2 could markedly impair SHR ability to induce periclinal division.
结果-SA:We also revealed that salicylic acid (SA) could promote H2O2 level via repressing CAT expression, which greatly increased periclinal division in root endodermis. As a result, middle cortex was more frequently formed in the endodermis of snc1, a mutant with accumulated endogenous SA and H2O2.
结果-SHR-SA-ROS:In addition to RBOHs, SHR also activated SA pathway, which might contribute to the elevated H2O2 level induced by SHR.
结论:Thus, our data suggest a mechanism by which SHR creates the optimal micro‐environment for periclinal division by maintaining ROS homeostasis in Arabidopsis roots.
摘 要
不对称细胞分裂的精确调控对于植物的器官发生至关重要。在拟南芥的根中,SHR作用于促进皮层/内皮层起始细胞(cortex/endodermis iitials, CEI)进行平周分裂,从而产生基本组织(ground tissue)模式。目前已经鉴定了多个下游的转录因子以及植物激素通路之间的互作参与这一过程,但是影响SHR介导的平周分裂的细胞层面的机制还存在较大的研究空白。本文中,作者发现SHR能够通过激活呼吸爆发氧化酶同系物,从而极大的提升拟南芥中活性氧(reactive oxygen species, ROS)的水平。在所有的ROS中,过氧化氢H2O2要比超氧离子O2‐在SHR介导的平周分裂中发挥更加重要的作用。过氧化氢的清除可以明显的导致SHR诱导平周分裂的能力缺陷。另外,作者还发现水杨酸SA能够通过抑制抗氧化酶基因CAT的表达来促进H2O2的水平,从而极大的增强了根内皮层中的平周分裂。因此,在一个积累内源水杨酸SA和H2O2的snc1突变体中,内皮层中会不断形成中间皮层。除了呼吸爆发氧化酶外,SHR还能够激活SA通路,这可能也作用于由SHR诱导的H2O2水平的提升。因此,本文的研究揭示了SHR通过维持拟南芥根中的ROS内稳态,创造了一个适合平周分裂的最佳微环境。
通讯作者
**吴双**
个人简介:
2003-2009年,美国麻省大学,博士;
2009-2014年,美国宾夕法尼亚大学,博后。
研究方向:
植物干细胞分裂和分化的分子学基础;
细胞间信号通讯调控植物发育的系统生物学研究;
植物根系营养与逆境适应的细胞分子学机制;
番茄,青梗菜等蔬菜生长调控和品质优化的分子基础。
doi: 10.1111/nph.16824
Journal: New Phytologist
First Published: July 24, 2020
Archiver|手机版|科学网 ( 京ICP备07017567号-12 )
GMT+8, 2024-10-19 21:40
Powered by ScienceNet.cn
Copyright © 2007- 中国科学报社