细胞壁对于植物细胞的生长和发育非常重要，而花粉管这个顶端极性生长的细胞其壁的结构和合成又有其特殊性。虽然一些基因被报道参与花粉管细胞壁的合成，但我们对花粉管细胞壁合成的调控机制了解得仍有限。GPI锚定蛋白SHV3和同源蛋白SVL1调控拟南芥根毛和下胚轴的生长，两个基因突变后细胞壁纤维素的含量下降，可能通过影响蔗糖的运输调控细胞壁的纤维素合成。纤维素是花粉管内壁的重要成分，我们鉴定到SHV3的同源基因SVL4和SVL5在雄配子体中特异表达，通过CRISPR-cas9技术获得了svl4svl5双突变体：角果短小，育性下降，花粉管萌发和生长受到抑制。本项目主要研究SVL4和SVL5基因的功能，观察突变体的发育表型；分析它们在花粉管细胞壁合成中的作用；分离与SVL相互作用的蛋白。以期揭示SVL基因调控花粉管壁生物合成的分子机制，为研究花粉管的极性生长和植物细胞壁合成的调控机制提供理论资料。

Cell walls are essential for plants to grow and develop. The stucture and biosynthesis of cell wall in pollen tube, a tip-growth cell, have their own special characteristics. Although a few genes have been reported to involve in the biosynthesis of the pollen tube wall, the molecular mechanisms that control pollen tube wall biosynthesis remain largely unknown. SHV3 and its homolog SVL1 encode GPI-anchored proteins that are involved in the growth of root hairs and hypocotyl in Arabidopsis. The double mutant shv3 svl1 exhibit a marked cellulose deficiency. SHV3 and SVL1 may regulate the cellulose synthesis of cell wall by control the transports of sucrose. The cellulose is an important componant of the inner wall of pollen tubes. In previous work, we identitied that the SVL4 and SVL5, homologs of SHV3, are expressed specifically in the development of male gametophytes in Arabidopsis. The double mutant, svl4 svl5 has been achieved by the CRISPR-Cas9 assay, which shows short siliques and dramatically reduced fertility. Furthormore, the germination and growth of pollen tubes in svl4 svl5 are repressive. In this project, we mainly study the functional characterization of SVL4 and SVL5 genes. At first,their mutations phenotypes on the development of male gametophyte will be detailed observed. Then, the role of these SVL gens on the biosynthesis of pollent tube wall will be analyzed. Furthmore, the interacted protein of SVL will be identified or isolated. This project aims to understand new molecular mechanisms that regulate the biosynthesis of the pollen tube wall in order to provide the academic data for studies on the tip-growth of pollen tubes and the biosynthesis of plant cell walls.