Independent S-locus mutations caused self-fertility in Arabidopsis thaliana.
Independent S-locus mutations caused self-fertility in Arabidopsis thaliana.
复制标题
独立的S-locus突变导致拟南芥的自我育属性。
DOI：
10.1371/journal.pgen.1000426
复制
发表时间：
2009-03
期刊：
影响因子：
4.5
通讯作者：
Nasrallah ME
中科院分区：
文献类型：
--
作者：
Boggs NA;Nasrallah JB;Nasrallah ME
在开花植物中，一种常见但却鲜为人知的进化转变是从近亲繁殖到近亲繁殖的交配模式的转变。模式植物拟南芥（Arabidopsis thaliana）通过丧失自交不亲和而进化到近交状态，这是一个花粉排斥系统，柱头对花粉的识别是由s -座受体激酶（SRK）及其s -座富半胱氨酸配体（SCR）紧密相连和共同进化的等位基因决定的。对拟南芥（a . thaliana）的异交亲缘植物AlSRKb-SCRb基因对的转化表明，拟南芥（a . thaliana）不仅在s位点基因上，而且在其他自交不亲和所需的位点上，都有不同的隐性自育促进突变。然而，尚不清楚在拟南芥谱系中发生了多少次以及以何种方式向自我生育的转变。在这里，我们报告了我们鉴定的4个通过转化AlSRKb-SCRb恢复到完全自交不亲和的材料，使自交不亲和的材料数量达到5个，这些材料是由于s位点失活造成的，也可能是由s位点失活造成的。对S-单倍型组织的分析表明，单倍型间重组事件、重排和缺失对这些材料中的S位点及其基因进行了重组。我们还进行了定量性状位点（QTL）分析，以确定col0参考种质中与自育相关的修饰位点，这些修饰位点不能恢复到完全自交不亲和。我们的研究结果表明，向近交的过渡至少发生了两个，可能更多，独立的s位点突变，并确定了一个新的不稳定修饰位点，有助于col0的自育。一个物种所采用的交配制度对其多态性程度、种群结构和进化潜力有着深远的影响。在开花植物中，从远亲繁殖到近亲繁殖的转变反复发生，但对潜在的遗传事件知之甚少。即使是十字花科中高度自我繁殖的模式物种拟南芥也是如此。在这个家族中，远交是由S位点控制的自交不亲和系统强制执行的，该系统涉及柱头识别花粉以防止自交受精和家族近交。我们最近证明，拟南芥（a.thaliana）可以通过转化其自交不亲和的亲缘拟南芥（a.lyrata）分离的s位点基因，恢复到完全或部分自交不亲和状态。然而，尽管最近有很多争论，我们仍然不知道拟南芥是如何实现自我繁殖的。在这里，我们使用我们最近建立的拟南芥转基因自交不亲和实验模型来解决这些问题。对可恢复到完全自交不亲和状态的材料中的S位点的分析表明，拟南芥的自育性至少由两个独立的S位点突变引起。此外，对一个只表达部分自交不亲和的基因的分析表明，自育性与一个与S位点无关的位点上的不稳定等位基因有关。
A common yet poorly understood evolutionary transition among flowering plants is a switch from outbreeding to an inbreeding mode of mating. The model plant Arabidopsis thaliana evolved to an inbreeding state through the loss of self-incompatibility, a pollen-rejection system in which pollen recognition by the stigma is determined by tightly linked and co-evolving alleles of the S-locus receptor kinase (SRK) and its S-locus cysteine-rich ligand (SCR). Transformation of A. thaliana, with a functional AlSRKb-SCRb gene pair from its outcrossing relative A. lyrata, demonstrated that A. thaliana accessions harbor different sets of cryptic self-fertility–promoting mutations, not only in S-locus genes, but also in other loci required for self-incompatibility. However, it is still not known how many times and in what manner the switch to self-fertility occurred in the A. thaliana lineage. Here, we report on our identification of four accessions that are reverted to full self-incompatibility by transformation with AlSRKb-SCRb, bringing to five the number of accessions in which self-fertility is due to, and was likely caused by, S-locus inactivation. Analysis of S-haplotype organization reveals that inter-haplotypic recombination events, rearrangements, and deletions have restructured the S locus and its genes in these accessions. We also perform a Quantitative Trait Loci (QTL) analysis to identify modifier loci associated with self-fertility in the Col-0 reference accession, which cannot be reverted to full self-incompatibility. Our results indicate that the transition to inbreeding occurred by at least two, and possibly more, independent S-locus mutations, and identify a novel unstable modifier locus that contributes to self-fertility in Col-0. The mating system adopted by a species has a profound influence on extent of polymorphism, population structure, and evolutionary potential. In flowering plants, the switch from outbreeding to inbreeding has occurred repeatedly, yet little is known about the underlying genetic events. This is true even for the model species A. thaliana, a highly self-fertile member of the crucifer family. In this family, outbreeding is enforced by a self-incompatibility system controlled by the S locus, which involves the recognition of pollen by the stigma to prevent self-fertilization and familial inbreeding. We recently demonstrated that A. thaliana accessions may be reverted to full or partial self-incompatibility by transformation with S-locus genes isolated from its close self-incompatible relative A. lyrata. Despite much recent debate, however, we still do not know how A. thaliana became self-fertile. Here, we use our recently established A. thaliana transgenic self-incompatible experimental model to address these issues. Analysis of the S locus in accessions that can be reverted to full self-incompatibility demonstrates that self-fertility in A. thaliana arose by at least two independent S-locus mutations. Furthermore, analysis of an accession that expresses only partial self-incompatibility shows that self-fertility is associated with an unstable allele at a locus unlinked to the S locus.
登录
查看更多内容
影响因子：
4.9
作者：
Cano, J. M.;Matsuba, C.;Merila, J.
通讯作者：
Merila, J.
影响因子：
11.6
作者：
Kusaba, M;Dwyer, K;Nasrallah, ME
通讯作者：
Nasrallah, ME
DOI：
10.1073/pnas.0406970101
发表时间：
2004-11-09
影响因子：
11.1
作者：
Nasrallah, ME;Liu, P;Nasrallah, JB
通讯作者：
Nasrallah, JB
影响因子：
7.2
作者：
Madlung, A;Tyagi, AP;Comai, L
通讯作者：
Comai, L
影响因子：
14.9
作者：
MURRAY, MG;THOMPSON, WF
通讯作者：
THOMPSON, WF