OsCAND1 Is Required for Crown Root Emergence in Rice  

作　　者：Xiao-Fei Wang Fen-Fang He Xiao-Xia Ma Chuan-Zao Mao Charlie Hodgman Chun-Gui Lu Ping Wu 

机构地区：[1]State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou, 310058, P.R. China [2]Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK

出　　处：《Molecular Plant》2011年第2期289-299,共11页分子植物（英文版）

摘　　要：Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant defective in crown root emergence designated as Oscand1 （named after the Arabidopsis homologous gene AtCAND1）. The defect of visible crown root in the Oscandl mutant is the result of cessation of the G2/M cell cycle transition in the crown root meristem. Map-based cloning revealed that OsCAND1 is a homolog ofArabidopsis CAND1. During crown root primordium development, the expression of OsCAND1 is confined to the root cap after the establishment of fundamental organization. The transgenic plants harboring DRS：：GUS showed that auxin signaling in crown root tip is abnormal in the mutant. Exogenous auxin application can partially rescue the defect of crown root development in Oscandl. Taken together, these data show that O5CAND1 is involved in auxin signaling to maintain the G2/M cell cycle transition in crown root meristem and, consequently, the emergence of crown root. Our findings provide new information about the molecular regulation of the emergence of crown root in rice.Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant defective in crown root emergence designated as Oscand1 （named after the Arabidopsis homologous gene AtCAND1）. The defect of visible crown root in the Oscandl mutant is the result of cessation of the G2/M cell cycle transition in the crown root meristem. Map-based cloning revealed that OsCAND1 is a homolog ofArabidopsis CAND1. During crown root primordium development, the expression of OsCAND1 is confined to the root cap after the establishment of fundamental organization. The transgenic plants harboring DRS：：GUS showed that auxin signaling in crown root tip is abnormal in the mutant. Exogenous auxin application can partially rescue the defect of crown root development in Oscandl. Taken together, these data show that O5CAND1 is involved in auxin signaling to maintain the G2/M cell cycle transition in crown root meristem and, consequently, the emergence of crown root. Our findings provide new information about the molecular regulation of the emergence of crown root in rice.

关 键 词：Oryza sativa L. emergence of crown root OsCAND1 cell cycle. 

分 类 号：Q78[生物学—分子生物学] S511.01[农业科学—作物学]