Evolution of the S-Locus Region in Arabidopsis Relatives
Evolution of the S-Locus Region in Arabidopsis Relatives
复制标题
DOI：
10.1104/pp.111.174912
复制
发表时间：
2011-10-01
期刊：
影响因子：
7.4
通讯作者：
Weigel, Detlef
中科院分区：
文献类型：
--
作者：
Guo, Ya-Long;Zhao, Xuan;Weigel, Detlef
S 基因座是一个单一的多态性基因座，导致十字花科和许多相关植物科的自交不亲和性 (SI)。尽管它很重要，但我们对 S 位点进化的了解在很大程度上仅限于编码 SI 系统的 S 位点受体激酶 (SRK) 受体和 S 位点富含半胱氨酸蛋白 (SCR) 配体的因果基因。在这里，我们展示了六种 S 基因座单倍型的基因组区域的高质量序列：拟南芥（拟南芥；一种单倍型）、琴叶拟南芥（四种单倍型）和荠菜（一种单倍型）。我们将这些与自交亲和拟南芥及其 SI 同系物琴叶拟南芥的参考 S 基因座单倍型进行了比较。随后，我们重建了拟南芥和荠菜最近共同祖先中 S 基因座可能的基因组组织。正如之前报道的，两个 SI 决定基因 SCR 和 SRK 显示出共同进化的模式。此外，与之前的研究一致，我们发现复制、基因转换和正选择是这两个基因进化的重要因素，并且似乎有助于新识别特异性的产生。有趣的是，自交亲和物种 C. rubella 中不活跃的假 S 基因座单倍型很可能是一个古老的 S 基因座单倍型，直到最近当 C. rubella 从它的 SI 祖先 Capsella grandiflora 中分离出来时才被固定。
The S locus, a single polymorphic locus, is responsible for self-incompatibility (SI) in the Brassicaceae family and many related plant families. Despite its importance, our knowledge of S-locus evolution is largely restricted to the causal genes encoding the S-locus receptor kinase (SRK) receptor and S-locus cysteine-rich protein (SCR) ligand of the SI system. Here, we present high-quality sequences of the genomic region of six S-locus haplotypes: Arabidopsis (Arabidopsis thaliana; one haplotype), Arabidopsis lyrata (four haplotypes), and Capsella rubella (one haplotype). We compared these with reference S-locus haplotypes of the self-compatible Arabidopsis and its SI congener A. lyrata. We subsequently reconstructed the likely genomic organization of the S locus in the most recent common ancestor of Arabidopsis and Capsella. As previously reported, the two SI-determining genes, SCR and SRK, showed a pattern of coevolution. In addition, consistent with previous studies, we found that duplication, gene conversion, and positive selection have been important factors in the evolution of these two genes and appear to contribute to the generation of new recognition specificities. Intriguingly, the inactive pseudo-S-locus haplotype in the self-compatible species C. rubella is likely to be an old S-locus haplotype that only very recently became fixed when C. rubella split off from its SI ancestor, Capsella grandiflora.