蕨类植物孢子与种子植物花粉萌发的比较

Comparison of Germination Between Fern Spores and Spermatophyte Pollen

蕨类植物孢子与种子植物花粉在有性生殖过程中都具有重要的作用。花粉作为种子植物的雄配子体,通过萌发后极性生长的花粉管将精细胞送到胚囊完成受精作用。蕨类植物孢子作为配子体的原始细胞,通过不对称的有丝分裂产生一大一小两个细胞,小细胞萌发出极性生长的假根,大细胞继续分裂发育为原叶体(配子体)。成熟的花粉和蕨类植物孢子都是代谢高度静止的细胞,两者的萌发过程不仅都受到各种不同环境因子的影响,而且在信号转导、极性建立和能量代谢等方面可能有着相似的调控机制。本文综述了蕨类植物孢子和种子植物花粉萌发过程的差异和保守性特征。

Fern spores and spermatophyte pollen have major roles in plant sex reproduction. As the male gametophyte, pollen delivers sperm to the embryo sac for fertilization by pollen-tube polarized growth. The fern spore, the original cell of the gametophyte, carries out asymmetrical mitosis to produce a large cell and a small cell. The small cell geminates to a rhizoid by tip growth, and the large cell further divides and develops to become a prothallus（the fern gametophyte）. Fern spores and pollen are metabolically quiescent cells, and their germination is affected by various environmental factors. Moreover, the germination of fern spores and pollen probably has similar molecular regulated mechanisms in cell division, polarity establishment and energy metabolism. This paper gives an overview of the different and conserved features of fern spores and spermatophyte pollen germination.