Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan.
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, 630-0192, Japan.
Nat Commun. 2020 Mar 16;11(1):1404. doi: 10.1038/s41467-020-15212-0.
Selfing is a frequent evolutionary trend in angiosperms, and is a suitable model for studying the recurrent patterns underlying adaptive evolution. Many plants avoid self-fertilization by physiological processes referred to as self-incompatibility (SI). In the Brassicaceae, direct and specific interactions between the male ligand SP11/SCR and the female receptor kinase SRK are required for the SI response. Although Arabidopsis thaliana acquired autogamy through loss of these genes, molecular evolution contributed to the spread of self-compatibility alleles requires further investigation. We show here that in this species, dominant SRK silencing genes have evolved at least twice. Different inverted repeat sequences were found in the relic SRK region of the Col-0 and C24 strains. Both types of inverted repeats suppress the functional SRK sequence in a dominant fashion with different target specificities. It is possible that these dominant suppressors of SI contributed to the rapid fixation of self-compatibility in A. thaliana.
自交是被子植物中常见的进化趋势，也是研究适应性进化背后反复出现模式的合适模型。许多植物通过被称为自交不亲和性（SI）的生理过程避免自花授粉。在十字花科中，雄性配体 SP11/SCR 和雌性受体激酶 SRK 之间的直接和特定相互作用是 SI 反应所必需的。尽管拟南芥通过失去这些基因获得了自交，但分子进化导致了自交亲和等位基因的传播，这需要进一步研究。我们在这里表明，在这个物种中，显性 SRK 沉默基因至少进化了两次。在 Col-0 和 C24 菌株的 SRK 区域中发现了不同的反向重复序列。这两种类型的反向重复以显性方式抑制具有不同靶特异性的功能性 SRK 序列。这些 SI 的显性抑制剂可能有助于拟南芥中自交亲和性的快速固定。
