TRICHOME BIREFRINGENCE-LIKE27 Affects Aluminum Sensitivity by Modulating the O-Acetylation of Xyloglucan and Aluminum-Binding Capacity in Arabidopsis

• Published in: Plant physiology (Bethesda) Vol. 166; no. 1; pp. 181 - 189
• Main Authors: Zhu, Xiao Fang, Sun, Ying, Zhang, Bao Cai, Mansoori, Nasim, Wan, Jiang Xue, Liu, Yu, Wang, Zhi Wei, Shi, Yuan Zhi, Zhou, Yi Hua, Zheng, Shao Jian
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Biologists 01.09.2014
• Subjects: Acetylation; Aluminum; Aluminum - metabolism; Arabidopsis - enzymology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cell Wall - metabolism; Cell walls; ECOPHYSIOLOGY AND SUSTAINABILITY; Glucans - metabolism; Holliday Junction Resolvases - genetics; Holliday Junction Resolvases - metabolism; Plant cells; Plant roots; Plant Roots - metabolism; Plants; Polysaccharides; Polysaccharides - metabolism; Rice; Root growth; Seedlings; Xylans - metabolism
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.114.243808

Xyloglucan (XyG) has been reported to contribute to the aluminum (Al)-binding capacity of the cell wall in Arabidopsis (Arabidopsis thaliana). However, the influence of O-acetylation of XyG, accomplished by the putative O-acetyltransferase TRICHOME BIREFRINGENCE-LIKE27 (TBL27 [AXY4]), on its Al-binding capacity is not known. In this study, we found that the two corresponding TBL27 mutants, axy4-1 and axy4-3, were more Al sensitive than wild-type Columbia-0 plants. TBL27 was expressed in roots as well as in leaves, stems, flowers, and siliques. Upon Al treatment, even within 30 min, TBL27 transcript accumulation was strongly down-regulated. The mutants axy4-1 and axy4-3 accumulated significantly more Al in the root and wall, which could not be correlated with pectin content or pectin methylesterase activity, as no difference in the mutants was observed compared with the wild type when exposed to Al stress. The increased Al accumulation in the wall of the mutants was found to be in the hemicellulose fraction. While the total sugar content of the hemicellulose fraction did not change, the O-acetylation level of XyG was reduced by Al treatment. Taken together, we conclude that modulation of the O-acetylation level of XyG influences the Al sensitivity in Arabidopsis by affecting the Al-binding capacity in the hemicellulose.