基于S- 核酸酶的自交不亲和性的分子机制

自交不亲和性是一种广泛存在于显花植物中的种内生殖障碍, 可以抑制近亲繁殖而促进异交。其中, 以茄科、玄参科和蔷薇科为代表的配子体自交不亲和性是最常见的类型。这类自交不亲和性是由单一的多态性S-位点所控制。目前的研究发现这一位点至少包含两个自交不亲和反应特异性决定因子: 花柱中的S-核酸酶和花粉中的SLF(S-Locus F-box)蛋白。该文将主要介绍并讨论基于S-核酸酶的自交不亲和性分子机制的研究进展。

Molecular Control of S-RNase-based Self-incompatibility

To avoid inbreeding and promote out-crossing, many flowering plants have adopted self-incompatibility (SI) systems, through which incompatible (self or genetically related) pollen is recognized and rejected, whereas compatible (non-self) pollen is allowed to grow in the style to deliver the germ cells to the ovary for double fertilization. Among various SI systems, gametophytic SI in Solanaceae, Scrophulariaceae and Rosaceae appears to be the most common whereby the specificity of SI response is controlled by a single polymorphic S-locus. Recent studies have shown that the S-locus is organized in a haplotype fashion and carries at least two genes determining the recognition specificity: S-ribonucleases expressed in the pistil (pistil-S) and S-locus Fbox(SLF) genes in the pollen (pollen-S). Here we discuss recent data on the possible molecular mechanisms eliciting the S-RNasebased self-incompatibility response.