title: OsKinesin-13A is an active microtubule depolymerase involved in glume length regulation via affecting cell elongation.
abstract: Grain size is an important trait influencing both the yield and quality of rice and its major determinant is glume size. However, how glume size is regulated remains largely unknown. Here, we report the characterization of OsKinesin-13A, which regulates cell elongation and glume length in rice. The mutant of OsKinesin-13A, sar1, displayed length reduction in grains and other organs including internodes, leaves and roots. The grain phenotype in sar1 was directly caused by reduction in glume length, which in turn restricted caryopsis size. Histological results revealed that length decrease in sar1 organs resulted from abnormalities in cell elongation. The orientation of cellulose microfibrils was defective in sar1. Consistently, sar1 showed reduced transverse orientation of cortical microtubules. Further observations demonstrated that microtubule turnover was decreased in sar1. OsKinesin-13A was shown to be an active microtubule depolymerase and mainly distributed on vesicles derived from the Golgi apparatus and destined for the cell surface. Thus, our results suggest that OsKinesin-13A utilizes its microtubule depolymerization activity to promote microtubule turnover, which may not only influence transverse orientation of cortical microtubules but also facilitate vesicle transport from the Golgi apparatus to the cell surface, and thus affects cellulose microfibril orientation and cell elongation.
authors: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Zhu Yun
authors: ZY
authors: Deng
authors: 1] Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Ling Tong
authors: LT
authors: Liu
authors: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Tang
authors: T
authors: Li
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of Ministry of Education of China, Agricultural College of Yangzhou University, Jiangsu 225009, China.
authors: Song
authors: S
authors: Yan
authors: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Bai Jian
authors: BJ
authors: Kuang
authors: School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors: Shan Jin
authors: SJ
authors: Huang
authors: Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of Ministry of Education of China, Agricultural College of Yangzhou University, Jiangsu 225009, China.
authors: Chang Jie
authors: CJ
authors: Yan
authors: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Tai
authors: T
authors: Wang
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000201:enzymology; D002482:Cellulose / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus / Q000235:genetics; D016547:Kinesins / Q000235:genetics* / Q000378:metabolism; D008870:Microtubules / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D018515:Plant Leaves / Q000201:enzymology; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000201:enzymology
chemical_list: D010940:Plant Proteins; D002482:Cellulose; D016547:Kinesins