title: Xyloglucan Endotransglucosylase-Hydrolase17 Interacts with Xyloglucan Endotransglucosylase-Hydrolase31 to Confer Xyloglucan Endotransglucosylase Action and Affect Aluminum Sensitivity in Arabidopsis.
abstract: Previously, we reported that although the Arabidopsis (Arabidopsis thaliana) Xyloglucan Endotransglucosylase-Hydrolase31 (XTH31) has predominately xyloglucan endohydrolase activity in vitro, loss of XTH31 results in remarkably reduced in vivo xyloglucan endotransglucosylase (XET) action and enhanced Al resistance. Here, we report that XTH17, predicted to have XET activity, binds XTH31 in yeast (Saccharomyces cerevisiae) two-hybrid and coimmunoprecipitations assays and that this interaction may be required for XTH17 XET activity in planta. XTH17 and XTH31 may be colocalized in plant cells because tagged XTH17 fusion proteins, like XTH31 fusion proteins, appear to target to the plasma membrane. XTH17 expression, like that of XTH31, was substantially reduced in the presence of aluminum (Al), even at concentrations as low as 10 µm for 24 h or 25 µm for just 30 min. Agrobacterium tumefaciens-mediated transfer DNA insertion mutant of XTH17, xth17, showed low XET action and had moderately shorter roots than the wild type but was more Al resistant than the wild type. Similar to xth31, xth17 had low hemicellulose content and retained less Al in the cell wall. These data suggest a model whereby XTH17 and XTH31 may exist as a dimer at the plasma membrane to confer in vivo XET action, which modulates cell wall Al-binding capacity and thereby affects Al sensitivity in Arabidopsis.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.).
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.).
authors.forename: Jiang Xue
authors.initials: JX
authors.lastname: Wan
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.).
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.).
authors.forename: Yuan Zhi
authors.initials: YZ
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.).
authors.forename: Janet
authors.initials: J
authors.lastname: Braam
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.).
authors.forename: Gui Xin
authors.initials: GX
authors.lastname: Li
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences (X.F.Z., J.X.W., Y.S, S.J.Z.), and College of Agronomy and Biotechnology (G.X.L.), Zhejiang University, Hangzhou 310058, China;Department of Plant Physiology and Nutrition, Tea Research Institute, Chinese Academy of Agricultural Sciences, the Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China (Y.Z.S.); andBiochemistry and Cell Biology, Rice University, Houston, Texas 77005 (J.B.) sjzheng@zju.edu.cn.
authors.forename: Shao Jian
authors.initials: SJ
authors.lastname: Zheng