Self-incompatibility triggers programmed cell death in Papaver pollen
Self-incompatibility triggers programmed cell death in Papaver pollen
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DOI：
10.1038/nature02540
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发表时间：
2004-05-20
期刊：
影响因子：
64.8
通讯作者：
Franklin-Tong, VE
中科院分区：
文献类型：
--
作者：
Thomas, SG;Franklin-Tong, VE
许多被子植物的有性生殖都存在自交不亲和性，这是防止近亲繁殖的重要机制之一。SI由S基因座遗传控制，并且涉及授粉期间花粉与其着陆的雌蕊之间的高度特异性相互作用。这导致排斥不相容的（“自体”）花粉，而相容的（“非自体”）花粉被允许使植物受精（1）。在虞美人中，由S基因座的柱头组分编码的S蛋白与不亲和的花粉相互作用，触发Ca 2+依赖的信号网络（2-7），导致花粉管生长的抑制。程序性细胞死亡（PCD）是许多生物体使用的一种机制，以精确调节的方式破坏不需要的细胞（8-10）。在这里，我们表明，PCD是由SI在一个S-特定的方式在不兼容的花粉。这提供了使用PCD的SI系统的演示，揭示了防止自花受精的新机制。此外，我们的数据显示，响应是双相的，快速抑制花粉管生长其次是PCD，这是在后来的“决策”阶段，使抑制不可逆的参与。
Sexual reproduction in many angiosperm plants involves self-incompatibility ( SI), which is one of the most important mechanisms to prevent inbreeding. SI is genetically controlled by the S-locus, and involves highly specific interactions during pollination between pollen and the pistil on which it lands. This results in the rejection of incompatible ('self') pollen, whereas compatible ('non-self') pollen is allowed to fertilize the plant(1). In Papaver rhoeas, S-proteins encoded by the stigma component of the S-locus interact with incompatible pollen, triggering a Ca2+-dependent signalling network(2-7), resulting in the inhibition of pollen-tube growth. Programmed cell death (PCD) is a mechanism used by many organisms to destroy unwanted cells in a precisely regulated manner(8-10). Here we show that PCD is triggered by SI in an S-specific manner in incompatible pollen. This provides a demonstration of a SI system using PCD, revealing a novel mechanism to prevent self-fertilization. Furthermore, our data reveal that the response is biphasic; rapid inhibition of pollen-tube growth is followed by PCD, which is involved in a later 'decision-making' phase, making inhibition irreversible.