TPLATE复合体亚基TML调控拟南芥花粉发育的研究

TML, One Subunit of TPLATE Complex, Regulates Pollen Development in Arabidopsis

网格蛋白介导的内吞作用参与调控花粉管的生长,但研究人员对其在花粉发育过程中的作用了解较少。TML是拟南芥TPLATE复合体的亚基,参与网格蛋白介导的内吞。该文利用CRISPR/Cas9技术创制了拟南芥TML的突变体tml-3,发现tml-3突变体的花粉形态异常且不能萌发。拟南芥花发育的11时期,花粉中能够检测到TML的表达, TML-YFP信号从花发育的12时期开始定位在花粉的质膜上。随着花粉的发育, TML表达水平逐渐升高,同时, tml-3突变体中败育花粉的比例也随花粉发育的进程逐渐升高。与野生型相比, tml-3花粉中的胼胝质、果胶质、纤维素的含量和分布均存在异常。推测在拟南芥花粉发育过程中, TML参与的内吞作用调控花粉胼胝质、果胶质及纤维素等多聚糖的积累。

Clathrin-mediated endocytosis plays roles in the regulation of pollen tube growth; however, its function in pollen development remains to be investigated. TML is one subunit of Arabidopsis TPLATE complex, which is implicated in clathrin-mediated endocytosis. In this study, we created an Arabidopsis mutant of TML, tml- 3, by using CRISPR/Cas9 strategy, in which the pollen showed abnormal morphology and germination. TML was expressed in the pollen from stage 11 and its protein was localized in plasma membrane in pollen from stage 12. The expression of TML was enhanced accompanied with the development of pollen, which was correlated with the ratio of the abortion pollen in the tml-3/＋ mutant, Furthermore, we found that the distribution and content of the polysaccha- ride were changed in the mutant pollen, such as callose, pectin, and cellulose, which suggests that the TML-regulated endocytosis is implicated in Arabidopsis pollen development by regulating polysaccharide accumulation.