高等植物自花花粉的识别与拒绝

高等植物在长期的进化过程中，通过雌蕊识别并拒绝遗传上相近的花粉，防止近亲繁殖、保持遗传多样性，该机制被称为植物自交不亲和性。植物自交不亲和性已成为当今国内外研究的热点。近年来，芸薹属孢子体自交不亲和性、S-RNase调节的配子体自交不亲和性以及罂粟花科配子体自交不亲和性研究比较深入。最近的研究表明，泛素介导的蛋白酶体蛋白质降解途径参与芸薹属孢子体自交不亲和性和S-RNase调节的配子体自交不亲和性反应。另一种蛋白质降解途径，即半胱-天冬胺酸特异的蛋白酶介导的细胞程序化死亡似乎参与罂粟花科配子体自交不亲和性。本文回顾了3种自交不亲和性研究的最新进展，并就其自交不亲和性机制作进一步讨论。

Self-pollen Recognition and Rejection in Flowering Plants

Self-incompatibility (SI) prevents inbreeding and promotes outcrossing by enabling pistils to recognize and reject pollen from genetically related individuals.Recent data have provided clear insights into some aspects of self-recognition and rejection in the SI response of three types,the single-locus sporophytic and two distinct forms of single-locus gametophytic SI.Emerging evidences implicate the involvement of ubiquitination and proteasomal degradation in both Brassica sporophytic (S) SI and S-ribonuclease (S-RNase)-based gametophytic (G) SI,and cysteinyl aspartate-specific protease (caspase)-like-mediated programmed cell death (PCD),another protein degradation pathway,seems to control the fate of self-pollen of Papaver.In this study,recent progresses were reviewed towards the elucidation of the three types of SI system and respective working models discussed.