Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, 12 Zhongguancun Nandajie, Beijing 100081, People's Republic of China.
Planta. 2010 May;231(6):1323-34. doi: 10.1007/s00425-010-1136-7. Epub 2010 Mar 13.
Pectin methylesterase (PME) is known to have important roles in pollen development and pollen tube growth. As pivotal regulatory factors in PME activity modulation, PME inhibitors (PMEIs) are thought to be key regulators of cell wall stability at the tip of the pollen tube. We report on the cloning and characterization of a novel B. oleracea PMEI gene, BoPMEI1. Heterologously expressed BoPMEI1 showed PMEI activity. RT-PCR studies of different tissues and promoter-GUS fusions confirmed that BoPMEI1 was specifically expressed in mature pollen grains and pollen tubes. Based on in vivo transient assays, we found that BoPMEI1 appears to be largely localized to the plasma membrane. Transgenic Arabidopsis plants expressing antisense BoPMEI1 under the control of the CaMV 35S promoter suppressed the expression of the orthologous gene At1g10770, which led to partial male sterility and decreased seed set by inhibition of pollen tube growth. Our study demonstrates the involvement of BoPMEI1 in pollen tube growth.
果胶甲酯酶（PME）在花粉发育和花粉管生长中具有重要作用。作为 PME 活性调节的关键调节因子，PME 抑制剂（PMEIs）被认为是花粉管尖端细胞壁稳定性的关键调节剂。我们报告了一种新型甘蓝 PMEI 基因 BoPMEI1 的克隆和特性。异源表达的 BoPMEI1 表现出 PMEI 活性。不同组织的 RT-PCR 研究和启动子-GUS 融合证实，BoPMEI1 特异性表达于成熟花粉粒和花粉管中。基于体内瞬时测定，我们发现 BoPMEI1 似乎主要定位于质膜上。在 CaMV 35S 启动子的控制下，表达反义 BoPMEI1 的转基因拟南芥植株抑制了同源基因 At1g10770 的表达，这导致部分雄性不育和种子产量下降，这是由于花粉管生长受到抑制。我们的研究表明 BoPMEI1 参与花粉管生长。
