Liu Ya-Bao, Lu Si-Min, Zhang Jian-Feng, Liu Sheng, Lu Ying-Tang
Key Lab of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Planta. 2007 Nov;226(6):1547-60. doi: 10.1007/s00425-007-0591-2. Epub 2007 Aug 3.
Xyloglucan endotransglucosylase/hydrolases (XTHs) are a class of enzymes that mediate the construction and restructure of the cellulose/xyloglucan framework by splitting and reconnecting xyloglucan molecule cross-linking among cellulose microfibrils. Remodification of cellulose microfibrils within cell-wall matrices is realized to be one of the most critical steps in the regulation of cells expansion in plants. Thirty-three XTH genes have been found in Arabidopsis thaliana but their roles remain unclear. AtXTH21 (At2g18800), an Arabidopsis XTH gene that mainly expresses in root and flower, exhibits different expression profiles from other XTH members under hormone treatment. We examined loss-of-function mutants using T-DNA insertion lines and overexpression lines and found that the AtXTH21 gene played a principal role in the growth of the primary roots by altering the deposition of cellulose and the elongation of cell wall.
木葡聚糖内转糖基酶/水解酶（XTHs）是一类通过切断并重新连接纤维素微纤丝间的木葡聚糖分子交联来介导纤维素/木葡聚糖框架构建和重构的酶。细胞壁基质内纤维素微纤丝的重塑被认为是植物细胞扩张调控中最关键的步骤之一。拟南芥中已发现33个XTH基因，但其功能仍不清楚。AtXTH21（At2g18800）是拟南芥中的一个XTH基因，主要在根和花中表达，在激素处理下其表达谱与其他XTH成员不同。我们使用T-DNA插入系和过表达系检测了功能缺失突变体，发现AtXTH21基因通过改变纤维素沉积和细胞壁伸长在初生根生长中起主要作用。
