阿拉伯半乳糖蛋白在被子植物有性生殖中的作用

阿拉伯半乳糖蛋白(arabinogalactan-proteins,AGPs)是一类主要分布在细胞表面和胞外基质中的糖蛋白.它们在植物的雄性器官(花粉、花粉管、精细胞)、雌性器官(柱头、花柱、子房)和胚胎(合子胚和体细胞胚)等组织和细胞中均有大量的表达.大量研究表明AGPs在被子植物有性生殖过程中起着非常重要的作用,既可能参与花粉管粘附、营养、传导或提供信号的作用,也可能参与受精过程中配子识别和受精后胚胎的发育与分化等过程.该文就其分子结构、特性以及在植物有性生殖过程中各种器官和组织内的表达和功能研究进展做了较为全面的概述.

The Roles of Arabinogalactan-proteins in Sexual Reproduction of Angiosperms

Arabinogalactan-proteins (AGPs) are a class of proteoglycans distributed mainly in the cell surfaces and extracellular matrix of most plants. Their numerous expressions have been detected in many male reproductive organs (pollen, pollen tube and sperm), female repro- ductive organs (stigma, style and ovary) and em- bryos (zygotic and somatic embryos) in many plants. Numerous investigations have demon- strated that AGPs are involved in the process of sexual reproduction of angiosperms and play multiple roles, e.g., providing surface adhesion, nutrients and directional cues or signals for pol- len tubes. They may also participate in gametal recognition and embryo development and differentiation. But the mechanisms underlying these roles ofAGPs are still unclear. Knowledge of AGPs in the structural components, characteristics, expression in reproductive tissues during the process of reproduction are summa- rized and the mechanisms underlying their func- tioning are discussed.