文献类型：期刊文献

英文题名：Three UDP-xylose transporters participate in xylan biosynthesis by conveying cytosolic UDP-xylose into the Golgi lumen in Arabidopsis

作者：Zhao, Xianhai[1,2] Liu, Nian[1,2] Shang, Na[1,2] Zeng, Wei[3] Ebert, Berit[4] Rautengarten, Carsten[4] Zeng, Qing-Yin[5] Li, Huiling[1,2] Chen, Xiaoyang[1,2] Beahan, Cherie[3] Bacic, Antony[3] Heazlewood, Joshua L.[4] Wu, Ai-Min[1,2]

第一作者：Zhao, Xianhai

通信作者：Wu, AM[1];Wu, AM[2];Heazlewood, JL[3]

机构：[1]South China Agr Univ, State Key Lab Conservat & Utilizat Subtrop Agrobi, Guangzhou 510642, Guangdong, Peoples R China;[2]South China Agr Univ, Coll Forestry & Landscape Architecture, Guangdong Key Lab Innovat Dev & Utilizat Forest P, Guangzhou 510642, Guangdong, Peoples R China;[3]Univ Melbourne, Sch BioSci, ARC Ctr Excellence Plant Cell Walls, Parkville, Vic 3010, Australia;[4]Univ Melbourne, Sch BioSci, Parkville, Vic 3010, Australia;[5]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China

年份：2018

卷号：69

期号：5

起止页码：1125-1134

外文期刊名：JOURNAL OF EXPERIMENTAL BOTANY

收录：;Scopus(收录号：2-s2.0-85042626192);WOS:【SCI-EXPANDED(收录号:WOS:000426147200016)】；

基金：Arabidopsis mutants were obtained from the ABRC at Ohio State University (www. arabidopsis. org). This work was supported by the National Key Research and Development Program of China (grant no. 2016YFD0600105), the National Natural Science Foundation of China (grant no. 31670670 and 31170165), the Guangdong Province Science and Technology Projects (grant no. 2015A050502045 and 2016A010104012) and Open Fund of State Key Laboratory of Tree Genetics and Breeding (Beijing). JLH and BE are supported by Australian Research Council Future Fellowships (grant no. FT130101165 and FT160100276). AB acknowledges support from the Australia Research Council to the ARC Centre of Excellence in Plant Cell Walls (grant no. CE1101007).

语种：英文

外文关键词：Arabidopsis; cell wall; nucleotide sugar; UDP-xylose; UDP-xylose synthase; UDP-xylose transporter; xylan

摘要：The cytosolic pool of UDP-xylose and its transport into the Golgi lumen play an essential role in xylan and xyloglucan biosynthesis. The equilibrium of these nucleotide sugar pools is controlled by UDP-xylose transporters.UDP-xylose (UDP-Xyl) is synthesized by UDP-glucuronic acid decarboxylases, also termed UDP-Xyl synthases (UXSs). The Arabidopsis genome encodes six UXSs, which fall into two groups based upon their subcellular location: the Golgi lumen and the cytosol. The latter group appears to play an important role in xylan biosynthesis. Cytosolic UDP-Xyl is transported into the Golgi lumen by three UDP-Xyl transporters (UXT1, 2, and 3). However, while single mutants affected in the UDP-Xyl transporter 1 (UXT1) showed a substantial reduction in cell wall xylose content, a double mutant affected in UXT2 and UXT3 had no obvious effect on cell wall xylose deposition. This prompted us to further investigate redundancy among the members of the UXT family. Multiple uxt mutants were generated, including a triple mutant, which exhibited collapsed vessels and reduced cell wall thickness in interfascicular fiber cells. Monosaccharide composition, molecular weight, nuclear magnetic resonance, and immunolabeling studies demonstrated that both xylan biosynthesis (content) and fine structure were significantly affected in the uxt triple mutant, leading to phenotypes resembling those of the irx mutants. Pollination was also impaired in the uxt triple mutant, likely due to reduced filament growth and anther dehiscence caused by alterations in the composition of the cell walls. Moreover, analysis of the nucleotide sugar composition of the uxt mutants indicated that nucleotide sugar interconversion is influenced by the cytosolic UDP-Xyl pool within the cell. Taken together, our results underpin the physiological roles of the UXT family in xylan biosynthesis and provide novel insights into the nucleotide sugar metabolism and trafficking in plants.