PLOS Genetics:中科院植物所王台研究组揭示花粉管细胞完整性调控

摘要 : 2016年7月27日,国际知名生命科学期刊《PLOS genetics》杂志上在线发表了中国科学院植物研究所植物分子生理学重点实验室王台研究组在花粉管细胞完整性调控机制的研究论文

2016年7月27日,国际知名生命科学期刊《PLOS genetics》杂志上在线发表了中国科学院植物研究所植物分子生理学重点实验室王台研究组在花粉管细胞完整性调控机制的研究论文,研究题为“Receptor-Like Kinase RUPO Interacts with Potassium Transporters to Regulate Pollen Tube Growth and Integrity in Rice”。博士研究生刘玲童为论文的第一作者,王台研究员为论文通讯作者。

在植物有性生殖过程中,授粉到雌蕊柱头上的花粉细胞萌发产生极性生长的花粉管,花粉管能够快速地在雌蕊内生长,最终将精细胞运输送到雌蕊的胚囊启动受精和胚胎发育。这种特性要求花粉管持续地与雌性细胞的交流互作以及对自身细胞壁和质膜张力变化的监控,从而使快速生长的花粉管在释放精细胞之前能维持细胞的完整性,但其分子细胞学机制尚不清楚。王台研究组发现水稻花粉管质膜定位的类受体激酶RUPO是维持花粉管细胞完整性信号通路的重要信号分子。RUPO基因在花粉中特异性表达,其功能缺失导致花粉的钾离子浓度显著升高和花粉管破裂。 研究发现RUPO与高亲和性的钾转运蛋白互作,RUPO磷酸化修饰促进这种互作,而去磷酸化解除了他们的互作。这些结果显示类受体激酶RUPO以磷酸化依赖的方式调控钾转运蛋白,RUPO-钾转运蛋白模块通过影响细胞内的钾稳态调控花粉管的生长和完整性。该研究揭示了一个新的调控植物细胞完整性的信号通路,为深入理解细胞发育及其完整性调控机制提供了新知识,也为植物雄性育性的遗传操作提供了新的基因原件。


图1. 纯合突变体(bi-allelic)花粉管在雌蕊中破裂。箭头显示雌蕊珠孔位置。


图2. RUPO-钾转运蛋白模块调控花粉管生长和细胞完整性的工作模型。

原文链接:

Receptor-Like Kinase RUPO Interacts with Potassium Transporters to Regulate Pollen Tube growth and Integrity in Rice

原文摘要:

During sexual reproduction of flowering plants, the pollen tube grows fast and over a long distance within the pistil to deliver two sperms for double fertilization. Growing Plant Cells need to communicate constantly with external stimuli as well as monitor changes in surface tension of the cell wall and plasma membrane to coordinate these signals and internal growth machinery; however, the underlying mechanisms remain largely unknown. Here we show that the rice member of plant-specific receptor-like kinase CrRLK1Ls subfamily, Ruptured Pollen tube (RUPO), is specifically expressed in rice pollen. RUPO localizes to the apical plasma membrane and vesicle of pollen tubes and is required for male gamete transmission. K+ levels were greater in pollen of homozygous CRISPR-knockout lines than wild-type plants, and pollen tubes burst shortly after germination. We reveal the interaction of RUPO with high-affinity potassium transporters. Phosphorylation of RUPO established and dephosphorylation abolished the interaction. These results have revealed the receptor-like kinase as a regulator of high-affinity potassium transporters via phosphorylation-dependent interaction, and demonstrated a novel receptor-like kinase signaling pathway that mediates K+ homeostasis required for pollen tube growth and integrity.

doi:10.1371/journal.pgen.1006085

作者:王台

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