Independent Control by Each Female Gamete Prevents the Attraction of Multiple Pollen Tubes
Independent Control by Each Female Gamete Prevents the Attraction of Multiple Pollen Tubes
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DOI：
10.1016/j.devcel.2013.03.013
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发表时间：
2013-05-13
影响因子：
11.8
通讯作者：
Higashiyama, Tetsuya
中科院分区：
文献类型：
--
作者：
Maruyama, Daisuke;Hamamura, Yuki;Higashiyama, Tetsuya
在开花植物中，双受精通常由第一个花粉管完成，受精的胚珠随后抑制第二个花粉管的吸引。然而，第二个花粉管回避的机制仍不清楚。我们发现，无论是卵细胞或中央细胞受精失败损害了第二个花粉管回避拟南芥。一个类似的干扰所造成的破坏受精独立的种子（FIS）类polycomb抑制复合物2（FIS-PRC2），中央细胞和胚乳特异性染色质修饰基因沉默的复合物。因此，两个雌配子进化出了自己的信号通路。有趣的是，半成功受精诱导的第二个花粉管吸引使胚珠完成双受精，产生遗传上不同的胚和胚乳。因此，我们建议，每个雌配子独立地决定第二个花粉管回避，以最大限度地提高生殖适合开花植物。
In flowering plants, double fertilization is normally accomplished by the first pollen tube, with the fertilized ovule subsequently inhibiting the attraction of a second pollen tube. However, the mechanism of second-pollen-tube avoidance remains unknown. We discovered that failure to fertilize either the egg cell or the central cell compromised second-pollen-tube avoidance in Arabidopsis thaliana. A similar disturbance was caused by disrupting the fertilization-independent seed (FIS) class polycomb-repressive complex 2 (FIS-PRC2), a central cell- and endosperm-specific chromatin-modifying complex for gene silencing. Therefore, the two female gametes have evolved their own signaling pathways. Intriguingly, second-pollen-tube attraction induced by half-successful fertilization allowed the ovules to complete double fertilization, producing a genetically distinct embryo and endosperm. We thus propose that each female gamete independently determines second-pollen-tube avoidance to maximize reproductive fitness in flowering plants.