配子体自交不亲和雄性决定因子的鉴别及其功能研究进展

摘要

S-RNase-mediated gametophytic self-incompatibility (GSI) is controlled by a multiallelic S-locus at which two separate genes, the female (pistil) and male (pollen) specificity determinants, are tightly linked. This review described both the identification of pollen specific F-box genes, SLF/SFBs, in Antirrhinum, Petunia and Prunus species and the demonstration of SLF/SFB as pollen determinant together with their functions in GSI response. Recent studies of how the pollen determinant functions in pollination reaction revealed that pollen determinant interacted with S-RNases in a non-allele-specific manner. It targeted all of the non-self S-RNases for ubiquitination through a functional SCF complex and subsequent degradation via 26S proteasome pathway in compatible reaction. It allows pollen tube to reach into the embryo sac and to finish double fertilization. In incompatible response, the intact self S-RNases were left to function as a cytotoxin that degrades self-pollen tube RNA, resulting in the cessation of pollen tube growth.%配子体自交不亲和由具有多基因的单一位点S位点控制,该位点包括紧密连锁的雌性(雌蕊)和雄性(花粉)S决定因子.本文综述了近年来金鱼草、矮牵牛、李亚科植物花粉特异性F-box基因的鉴别及雄性S决定因子的鉴定,论述了雄性决定因子在自交不亲和反应中的功能研究进展.当前对雄性决定因子的功能研究认为,在亲和反应中它非特异地与S-RNases作用,通过形成一个功能的SCF复合体仅使非自身S-RNase被泛素介导的26S蛋白酶体降解,花粉管得以继续生长至胚囊完成双受精;而自身S-RNase的活性被特异保留,作为细胞毒素降解花粉管RNA,从而抑制自身花粉管的生长.