RNase-Based Self-Incompatibility: Puzzled by Pollen S
RNase-Based Self-Incompatibility: Puzzled by Pollen S
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DOI：
10.1105/tpc.108.060327
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发表时间：
2008-09-01
期刊：
影响因子：
11.6
通讯作者：
Kohn, Joshua R.
中科院分区：
文献类型：
--
作者：
Newbigin, Ed;Paape, Timothy;Kohn, Joshua R.
许多植物具有遗传决定的自交不亲和系统，其中自交花粉粒的排斥由S基因座的等位基因控制。这些S基因座的一个共同特征是，单独的花粉和花柱表达的基因（花粉S和花柱S，分别）决定S等位基因的身份。长期以来的观点是，花粉S和花柱S必须是一个共同进化的基因对，以便在新的S等位基因出现时保持等位基因识别。在至少三个植物科中，茄科、蔷薇科和车前草科，花柱S基因长期以来被认为编码一种称为S-RNase的细胞外核糖核酸酶。这些家族中的花粉S最近已被鉴定并编码称为SLF或SFB的F盒蛋白。从这个角度来看，我们描述了令人困惑的进化关系，SLF/SFB和S-RNase基因之间存在的，并表明，在大多数情况下，同源对基因没有共同进化的预期方式。由于一些花粉S基因出现得更近比他们的风格S同源，我们得出结论，一些花粉S基因已被错误地确定或有一个重大的问题，我们的理解是如何的S基因座的演变。
Many plants have a genetically determined self-incompatibility system in which the rejection of self pollen grains is controlled by alleles of an S locus. A common feature of these S loci is that separate pollen- and style-expressed genes (pollen S and style S, respectively) determine S allele identity. The long-held view has been that pollen S and style S must be a coevolving gene pair in order for allelic recognition to be maintained as new S alleles arise. In at least three plant families, the Solanaceae, Rosaceae, and Plantaginaceae, the style S gene has long been known to encode an extracellular ribonuclease called the S-RNase. Pollen S in these families has more recently been identified and encodes an F-box protein known as either SLF or SFB. In this perspective, we describe the puzzling evolutionary relationship that exists between the SLF/SFB and S-RNase genes and show that in most cases cognate pairs of genes are not coevolving in the expected manner. Because some pollen S genes appear to have arisen much more recently than their style S cognates, we conclude that either some pollen S genes have been falsely identified or that there is a major problem with our understanding of how the S locus evolves.