Arabidopsis Galacturonosyltransferase （GAUT） 13 and GAUT14 Have Redundant Functions in Pollen Tube Growth

• Published in: 分子植物：英文版 2013 (4), p.1131-1148
• Main Author: Li Wang Wei Wang You-Qun Wang Yang-Yang Liu Jing-Xin Wang Xue-Qin Zhang De Ye Li-Qun Chen
• Format: Article
• Language: English
• Subjects: T-DNA插入; 冗余功能; 拟南芥; 氨基酸序列; 生物合成; 突变体; 细胞壁; 花粉管生长
• ISSN: 1674-2052; 1752-9867

Cell wall biosynthesis is indispensable for pollen tube growth. Despite its importance to sexual reproduction, the molecular mechanisms of pollen tube wall biosynthesis remain poorly understood. Here, we report functional characterization of two putative Arabidopsis galacturonosyltransferase genes, GAUT13 and GAUT14, which are essential for pollen tube growth. GAUT13 and GAUT14 encode the proteins that share a high amino acid sequence identity and are located in the Golgi apparatus. The T-DNA insertion mutants, gaut13 and gaut14, did not exhibit any observable defects, but the gaut13 gaut14 double mutants were defective in pollen tube growth; 35.2-37.3% pollen tubes in the heterozygous double mutants were swollen and defective in elongation. The outer layer of the cell wall did not appear distinctly fibrillar in the double mutant pollen tubes. Furthermore, distribution of homogalacturonan labeled with JIM5 and JIM7 in the double mutant pollen tube wall was significantly altered compared to wild-type. Our results suggest that GAUT13 and GAUT14 function redundantly in pollen tube growth, possibly through participation in pectin biosynthesis of the pollen tube wall.