RAF-like MAPKKKs RAF22 and RAF28 are required for the regulation of embryogenesis in Arabidopsis
RAF-like MAPKKKs RAF22 and RAF28 are required for the regulation of embryogenesis in Arabidopsis
复制标题
RAF 样 MAPKKKs RAF22 和 RAF28 是拟南芥胚胎发生调控所必需的
DOI：
10.1111/tpj.14063
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Ren Dongtao
中科院分区：
文献类型：
--
作者：
Wang Bo;Liu Guting;Zhang Jing;Li Yuan;Yang Hailian;Ren Dongtao
在拟南芥中，胚胎发育遵循一种典型的细胞分裂模式。虽然有许多因素参与了胚胎模式的建立，但模式形成的分子机制尚不清楚。本研究表明，拟南芥中两种类似于RAF的有丝分裂原激活蛋白激酶激酶激酶（MAPKKKs） RAF22和RAF28参与了胚胎发生的调控。双敲除突变体raf22和raf28具有胚胎致死性。大量的theraf22−/−raf28+/−突变胚表现出各种缺陷，包括原胚细胞分裂紊乱、两侧对称结构破坏、垂体形成分裂异常和胚柄生长过度。而激酶活性形式的RAF22可以补充这些胚胎异常表型，激酶无活性形式不能。异常胚柄细胞中基底细胞命运标记物WOX8的限制性表达和异常胚前体细胞中根尖细胞谱系标记物WOX2的限制性表达表明，异常胚的根尖和基底细胞命运未发生改变。生长素maxima的极性分布以及生长素转运体PIN1和PIN7的极性分布在异常胚胎中发生了明显改变。我们的研究结果表明，RAF22和RAF28是胚胎发生的重要组成部分，生长素的极性运输可能参与了这一调控。
In Arabidopsis, embryonic development follows a stereotypical pattern of cell division. Although many factors have been reported to participate in establishment of the proper embryonic pattern, the molecular mechanisms underlying pattern formation are unclear. In this study we showed that RAF22 and RAF28, two RAF‐like mitogen‐activated protein kinase kinase kinases (MAPKKKs) in Arabidopsis, are involved in the regulation of embryogenesis. The double knockout mutant ofRAF22andRAF28was embryo lethal. A large proportion of theraf22−/−raf28+/−mutant embryos exhibited various defects, including disordered proembryo cell divisions, disruption of the bilaterally symmetrical structure, abnormally formative divisions of hypophysis and exaggerated suspensor growth. Whereas the kinase active form of RAF22 could complement these embryonic aberrant phenotypes, the kinase inactive form could not. The restrictive expression of the basal cell fate marker WOX8 in the abnormally dividing suspensor cells and the apical cell linage marker WOX2 in the abnormal proembryos indicated that apical and basal cell fates were unchanged in the abnormal embryos. The polar distribution of the auxin maxima and the PIN1 and PIN7 auxin transporters was markedly altered in the abnormal embryos. Our results suggest that RAF22 and RAF28 are important components of embryogenesis and that auxin polar transport may be involved in this regulation.