Arabinogalactan proteins as molecular markers in Arabidopsis thaliana sexual reproduction
Arabinogalactan proteins as molecular markers in Arabidopsis thaliana sexual reproduction
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DOI：
10.1093/jxb/erm259
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发表时间：
2007-01-01
影响因子：
6.9
通讯作者：
Pereira, Luis Gustavo
中科院分区：
文献类型：
--
作者：
Coimbra, Silvia;Almeida, Joao;Pereira, Luis Gustavo
植物在有性生殖过程中发生的一些最重要的变化涉及从孢子体发育类型向配子体类型发育的转变。在本文中，对拟南芥的这些变化进行了评估。获得的结果清楚地显示出差异；花药和胚珠发育过程中特定阿拉伯半乳聚糖蛋白 (AGP) 糖表位的分布模式。 AGP 是富含羟脯氨酸的糖蛋白，被大量糖基化并且在植物中普遍存在。 AGP 的分子作用机制仍不清楚，主要是由于复杂的糖链造成的困难。然而，AGP 糖部分的复杂结构使其成为信号分子的潜在来源。在拟南芥花粉和雌蕊发育过程中，使用 AGP 单克隆抗体 JIM8、JIM13、MAC207 和 LM2 获得的选择性标记表明，某些 AGP 可以作为配子体细胞分化的标记。雌蕊中第一个配子体细胞的特异性标记、胚囊分泌细胞、助细胞的强标记以及珠被珠孔细胞的标记，显然勾勒出花粉管进入其最终目标胚囊的途径，所有这些都已被证明。在花药中，配子体细胞和沿着花粉管传播的雄配子的特定标记可能表明AGP表位充当花粉管到达其最终命运的信号。还讨论了注定要进入程序性细胞死亡的细胞的特定标记。
Some of the most important changes that occur in plants during sexual reproduction involve the transition from a sporophytic to a gametophytic type of development. In this paper, these changes were evaluated for Arabidapsis thaliana. The results obtained clearly show differences; in the pattern of distribution of specific arabinogalactan protein (AGP) sugar epitopes, during anther and ovule development. AGPs are hydroxyproline-rich glycoproteins that are massively glycosylated and ubiquitous in plants. The molecular mechanism of action of AGPs is still unknown, mainly due to the difficulties posed by the complex saccharide chains. However, the complex structure of the sugar fraction of AGPs makes them a potential source of signalling molecules.. The selective labelling obtained with AGP mAbs JIM8, JIM13, MAC207, and LM2, during Arabidopsis pollen and pistil development, suggests that some AGPs can work as markers for gametophytic cell differentiation. Specific labelling of the first gametophytic cells in the pistil, the strong labelling of the secretory cells of the embryo sac, the synergid cells, and the labelling of the integument micropylar cells, apparently outlining the pollen tube pathway into its final target, the embryo sac, have all been shown. In the anthers, the specific labelling of gametophytic cells, and of the male gametes that travel along the pollen tube, may indicate AGP epitopes acting as signals for the pollen tube to reach its final destiny. The specific labelling of cells destined to go into programmed cell death is also discussed.