Arabidopsis galacturonosyltransferase (GAUT) 13 and GAUT14 have redundant functions in pollen tube growth.
Arabidopsis galacturonosyltransferase (GAUT) 13 and GAUT14 have redundant functions in pollen tube growth.
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DOI：
10.1093/mp/sst084
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发表时间：
2013-07
期刊：
影响因子：
27.5
通讯作者：
Li Wang;Wei Wang;Youliang Wang;Yang-Yang Liu-Yang;Jing-Xin Wang;Xueqin Zhang;D. Ye;Li-Qun Chen
中科院分区：
文献类型：
--
作者：
Li Wang;Wei Wang;Youliang Wang;Yang-Yang Liu-Yang;Jing-Xin Wang;Xueqin Zhang;D. Ye;Li-Qun Chen
细胞壁的生物合成是花粉管生长所必需的。尽管它对有性繁殖很重要，但花粉管壁生物合成的分子机制仍然知之甚少。在这里，我们报告了两个可能的拟南芥半乳糖醛酸基转移酶基因GAUT13和GAUT14的功能特征，它们对花粉管的生长是必不可少的。GAUT13和GAUT14编码的蛋白质具有很高的氨基酸序列一致性，位于高尔基体中。T-DNA插入突变体gaut13和gaut14没有表现出任何明显的缺陷，但gaut13双突变体的花粉管生长存在缺陷，杂合型双突变体中35.2-37.3%的花粉管膨大和伸长缺陷。双突变体花粉管的细胞壁外层未见明显的纤维状结构。此外，与野生型相比，JIM5和JIM7标记的高半乳糖醛酸在双突变体花粉管壁中的分布发生了显著变化。我们的结果表明，GAUT13和GAUT14在花粉管生长过程中起冗余作用，可能是通过参与花粉管壁果胶的生物合成。
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.