An Aminoacyl tRNA Synthetase, OKI1, Is Required for Proper Shoot Meristem Size in Arabidopsis
An Aminoacyl tRNA Synthetase, OKI1, Is Required for Proper Shoot Meristem Size in Arabidopsis
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DOI：
10.1093/pcp/pcz153
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发表时间：
2019-11-01
影响因子：
4.9
通讯作者：
Jackson, David
中科院分区：
文献类型：
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作者：
Kitagawa, Munenori;Balkunde, Rachappa;Jackson, David
在植物中，形成茎系统的干细胞位于茎顶端分生组织(SAM)内，SAM受WUSCHEL(WUS)同源框蛋白与CLAVATA(CLV)多肽和受体之间的反馈信号调节。WUS-CLV反馈信号受染色质状态、激素信号、活性氧(ROS)信号和营养等多种内源或外源因素的调节，导致SAM大小与分生组织活性相对应的动态调控。然而，尽管有这些见解，控制SAM大小的基因的知识仍然有限，尤其是ROS信号的调控才刚刚开始被理解。在本研究中，我们报道了一个新的维持SAM大小的功能，它是由OkinasKUKI1(OKI1)基因编码的。OKI1在SAM中表达，编码线粒体天冬氨酸氨基转移酶合成酶(ASPRS)。Oki1突变体表现为SAM增大，WUS和CLV3表达异常，ROS在分生组织中过度积累。我们的发现支持了正常的ASPR功能在维持WUS-CLV3反馈环和SAM大小方面的重要性。
In plants, the stem cells that form the shoot system reside within the shoot apical meristem (SAM), which is regulated by feedback signaling between the WUSCHEL (WUS) homeobox protein and CLAVATA (CLV) peptides and receptors. WUS-CLV feedback signaling can be modulated by various endogenous or exogenous factors, such as chromatin state, hormone signaling, reactive oxygen species (ROS) signaling and nutrition, leading to a dynamic control of SAM size corresponding to meristem activity. Despite these insights, however, the knowledge of genes that control SAM size is still limited, and in particular, the regulation by ROS signaling is only beginning to be comprehended. In this study, we report a new function in maintenance of SAM size, encoded by the OKINA KUKI1 (OKI1) gene. OKI1 is expressed in the SAM and encodes a mitochondrial aspartyl tRNA synthetase (AspRS). oki1 mutants display enlarged SAMs with abnormal expression of WUS and CLV3 and overaccumulation of ROS in the meristem. Our findings support the importance of normal AspRS function in the maintenance of the WUS-CLV3 feedback loop and SAM size.