An Aminoacyl tRNA Synthetase, OKI1, Is Required for Proper Shoot Meristem Size in Arabidopsis. (8th August 2019)

• Record Type: Journal Article
• Authors: Kitagawa, Munenori; Balkunde, Rachappa; Bui, Huyen; Jackson, David
• Is Part Of: Plant & cell physiology. Volume 60:Number 11(2019)
• Page Start: 2597
• Page End: 2608
• Publication Date: 2019-08-08
• Subjects: Aminoacyl tRNA synthetase -- Arabidopsis thaliana -- Fasciation -- Mitochondria -- Redox -- Shoot meristem; Plant physiology -- Periodicals; Microbiology -- Periodicals; Cytology -- Periodicals; Cell Physiology -- Periodicals; Plant Physiological Phenomena -- Periodicals; Cytology; Microbiology; Plant physiology; Periodicals; 571.205
• DOI: 10.1093/pcp/pcz153
• Languages: English
• ISSNs: 0032-0781

Abstract

Abstract: 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.