Mutation in xyloglucan 6-xylosytransferase results in abnormal root hair development in Oryza sativa.
Root hairs are important for nutrient uptake, anchorage, and plant-microbe interactions. From a population of rice (Oryza sativa) mutagenized by ethyl methanesulfonate (EMS), a short root hair2 (srh2) mutant was identified. In hydroponic culture, srh2 seedlings were significantly reduced in root hair length. Bubble-like extrusions and irregular epidermal cells were observed at the tips of srh2 root hairs when grown under acidic conditions, suggesting the possible reduction of the tensile strength of the cell wall in this mutant. Map-based cloning identified a mutation in the gene encoding xyloglucan (XyG) 6-xylosyltransferase (OsXXT1). OsXXT1 displays more than 70% amino acid sequence identity with the previously characterized Arabidopsis thaliana XYG XYLOSYL TRANSFERASE 1 (AtXXT1) and XYG XYLOSYL TRANSFERASE 2 (AtXXT2), which catalyse the transfer of xylose onto β-1,4-glucan chains. Furthermore, expression of the full-length coding sequence of OsXXT1 could complement the root hair defect, and slow growth and XyG synthesis in the Arabidopsis xxt1 xxt2 double mutant. Transgenic plants expressing the β-glucuronidase (GUS) reporter under the control of the OsXXT1 promoter displayed GUS expression in multiple tissues, most prominently in root epidermal cells. These results demonstrate the importance of OsXXT1 in maintaining cell wall structure and tensile strength in rice, a typical grass species that contains relatively low XyG content in cell walls.
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China University of Western Australia-Zhejiang University Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China.
Chuang
C
Wang
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China.
Shuai
S
Li
University of Western Australia-Zhejiang University Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009 Western Australia, Australia.
Sophia
S
Ng
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Baocai
B
Zhang
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Yihua
Y
Zhou
University of Western Australia-Zhejiang University Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China Department of Botany, School of Life Science, Australian Research Council Centre of Excellence in Plant Energy Biology, La Trobe University, Bundara, Victoria 3086, Australia.
James
J
Whelan
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China University of Western Australia-Zhejiang University Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China.
Ping
P
Wu
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China University of Western Australia-Zhejiang University Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, P. R. China huixia@zju.edu.cn.
Huixia
H
Shou
D017360:Arabidopsis; D002473:Cell Wall / Q000502:physiology*; D005816:Genetic Complementation Test; D009154:Mutation; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010430:Pentosyltransferases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism; D013718:Tensile Strength
D010940:Plant Proteins; D010430:Pentosyltransferases; C029368:xyloglucan xylosyltransferase
Rice; root hair; type I cell wall; type II cell wall; xyloglucan; xylosyltransferase.