The Glycerophosphoryl Diester Phosphodiesterase-Like Proteins SHV3 and its Homologs Play Important Roles in Cell Wall Organization
The Glycerophosphoryl Diester Phosphodiesterase-Like Proteins SHV3 and its Homologs Play Important Roles in Cell Wall Organization
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DOI：
10.1093/pcp/pcn120
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发表时间：
2008-10-01
影响因子：
4.9
通讯作者：
Hirayama, Takashi
中科院分区：
文献类型：
--
作者：
Hayashi, Shimpei;Ishii, Tadashi;Hirayama, Takashi
尽管细胞外事件在细胞壁组织和生物发生中的重要性，但其机制和相关因素在很大程度上是未知的。我们分离出一个等位基因的shaven3（shv3）突变体的拟南芥，表现出破裂的根毛细胞在尖端生长。SHV 3编码一种新的蛋白质，具有两个串联重复的甘油磷酸二酯磷酸二酯酶样结构域和一个糖基磷脂酰肌醇锚，并且在拟南芥中发现了它的几个旁系同源物。在这里，我们报告了SHV3及其旁系同源物SVL1的突变体的详细特征。shv3和svl1双突变体表现出额外的缺陷，包括肿胀的保卫细胞，下胚轴表皮的异常扩张和异位木质素沉积，这表明细胞壁的硬度下降。傅立叶变换红外光谱和测量的细胞壁成分表明，改变纤维素含量和果胶的双突变体中的交联改性。此外，我们发现shv3的根毛破裂表型受到抑制，通过增加硼酸盐的量，这应该是参与果胶多糖交联，在培养基中。这些发现表明SHV3及其旁系同源物是参与初生细胞壁组织的新的重要因子。
Despite the importance of extracellular events in cell wall organization and biogenesis, the mechanisms and related factors are largely unknown. We isolated an allele of the shaven3 (shv3) mutant of Arabidopsis thaliana, which exhibits ruptured root hair cells during tip growth. SHV3 encodes a novel protein with two tandemly repeated glycerophosphoryl diester phosphodiesterase-like domains and a glycosylphosphatidylinositol anchor, and several of its paralogs are found in Arabidopsis. Here, we report the detailed characterization of mutants of SHV3 and one of its paralogs, SVL1. The shv3 and svl1 double mutant exhibited additional defects, including swollen guard cells, aberrant expansion of the hypocotyl epidermis and ectopic lignin deposits, suggesting decreased rigidity of the cell wall. Fourier-transform infrared spectroscopy and measurement of the cell wall components indicated an altered cellulose content and pectin modification with cross-linking in the double mutant. Furthermore, we found that the ruptured root hair phenotype of shv3 was suppressed by increasing the amount of borate, which is supposed to be involved in pectic polysaccharide cross-linking, in the medium. These findings indicate that SHV3 and its paralogs are novel important factors involved in primary cell wall organization.