The Pollen Receptor Kinase LePRK2 Mediates Growth-Promoting Signals and Positively Regulates Pollen Germination and Tube Growth
The Pollen Receptor Kinase LePRK2 Mediates Growth-Promoting Signals and Positively Regulates Pollen Germination and Tube Growth
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花粉受体激酶 LePRK2 介导生长促进信号并积极调节花粉萌发和花管生长
DOI：
10.1104/pp.108.124420
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发表时间：
2008-11-01
期刊：
影响因子：
7.4
通讯作者：
Tang, Wei-Hua
中科院分区：
文献类型：
--
作者：
Zhang, Dong;Wengier, Diego;Tang, Wei-Hua
在开花植物中，成功受精需要花粉萌发和管生长过程。来自番茄 (Solanum lycopersicum) 的花粉受体激酶 LePRK2 与花粉萌发和管生长期间的信号传导以及介导花粉（管）-雌蕊通讯有关。在这里，我们发现 LePRK2 表达的减少会影响花粉萌发和花管生长的四个方面。首先，花粉发芽的百分比减少，发芽的时间窗口也更短。其次，花粉管在体外和雌蕊中的生长速度均降低。第三，外源钙离子不能增加花粉管尖端局部超氧化物的产生。第四，花粉管对花柱提取物成分（STIL）的反应存在缺陷，STIL是来自雌蕊的细胞外生长促进信号。瞬时过表达 LePRK2-荧光蛋白融合体的花粉管具有稍宽的尖端，而共表达 LePRK2 及其细胞质伴侣蛋白 KPP（Rop-GEF）的花粉管具有更宽的尖端。这些结果共同表明，LePRK2 正向调节花粉萌发和花管生长，并参与转导对细胞外生长促进信号的反应。
In flowering plants, the process of pollen germination and tube growth is required for successful fertilization. A pollen receptor kinase from tomato (Solanum lycopersicum), LePRK2, has been implicated in signaling during pollen germination and tube growth as well as in mediating pollen (tube)-pistil communication. Here we show that reduced expression of LePRK2 affects four aspects of pollen germination and tube growth. First, the percentage of pollen that germinates is reduced, and the time window for competence to germinate is also shorter. Second, the pollen tube growth rate is reduced both in vitro and in the pistil. Third, tip-localized superoxide production by pollen tubes cannot be increased by exogenous calcium ions. Fourth, pollen tubes have defects in responses to style extract component (STIL), an extracellular growth-promoting signal from the pistil. Pollen tubes transiently overexpressing LePRK2-fluorescent protein fusions had slightly wider tips, whereas pollen tubes coexpressing LePRK2 and its cytoplasmic partner protein KPP (a Rop-GEF) had much wider tips. Together these results show that LePRK2 positively regulates pollen germination and tube growth and is involved in transducing responses to extracellular growth-promoting signals.