被子植物助细胞中钙含量的变化

助细胞是被子植物受精过程中花粉管进入胚囊并释放精子及其内容物的场所,而助细胞中不同时期的钙含量与受精作用的顺利完成密切相关。在大多数植物中,助细胞是成熟胚囊中钙含量最高的细胞。传粉后在花粉管中所产生的信号诱导下,助细胞中钙含量还可能继续增加。花粉管进入退化助细胞后,在超高钙环境中破裂并释放精子,精子沿退化助细胞转移到受精靶区实现双受精。随后助细胞中的钙含量迅速降低。因此钙在吸引花粉管、雄配子释放甚至雄配子转移等过程中都发挥了重要作用。

Changes of Calcium Concentration in Synergids of Angiosperms

Synergid cell is the place where pollen tube enters the embryo sac,releases sperms and its contents during the fertilization in angiosperms.And in the different development stages of synergid cell,calcium concentration and fertilization is closely related.In most plants,synergid cell is the most abundant cell of calcium in mature embryo sac.By the inducement of signals in pollen tubes after pollination,the calcium concentration continues to increase possibly.After entering the degenerated synergid,the pollen tube breaks and releases the sperms in the ultra-high calcium environment,and then,the sperms transfer to the target region of fertilization in order to complete the double fertilization.Calcium concentration in synergid cell rapidly reduces soon after.So calcium plays an important role during the process of attracting the pollen tube,releasing and transferring the male gamete.