Sassa Hidenori, Kakui Hiroyuki, Minamikawa Mai
Graduate School of Horticulture, Chiba University, Matsudo, Chiba, 271-8510, Japan.
Sex Plant Reprod. 2010 Mar;23(1):39-43. doi: 10.1007/s00497-009-0111-6. Epub 2009 Aug 30.
Many species of Rosaceae, Solanaceae, and Plantaginaceae exhibit S-RNase-based self-incompatibility (SI) in which pistil-part specificity is controlled by S locus-encoded ribonuclease (S-RNase). Although recent findings revealed that S locus-encoded F-box protein, SLF/SFB, determines pollen-part specificity, how these pistil- and pollen-part S locus products interact in vivo and elicit the SI reaction is largely unclear. Furthermore, genetic studies suggested that pollen S function can differ among species. In Solanaceae and the rosaceous subfamily Maloideae (e.g., apple and pear), the coexistence of two different pollen S alleles in a pollen breaks down SI of the pollen, a phenomenon known as competitive interaction. However, competitive interaction seems not to occur in the subfamily Prunoideae (e.g., cherry and almond) of Rosaceae. Furthermore, the effect of the deletion of pollen S seems to vary among taxa. This review focuses on the potential differences in pollen-part function between subfamilies of Rosaceae, Maloideae, and Prunoideae, and discusses implications for the mechanistic divergence of the S-RNase-based SI.
蔷薇科、茄科和车前科的许多物种表现出基于S-核酸酶的自交不亲和性（SI），其中雌蕊部分的特异性由S位点编码的核糖核酸酶（S-RNase）控制。尽管最近的研究结果表明，S位点编码的F-box蛋白SLF/SFB决定花粉部分的特异性，但这些雌蕊和花粉部分的S位点产物在体内如何相互作用并引发SI反应在很大程度上尚不清楚。此外，遗传学研究表明，不同物种间花粉S功能可能存在差异。在茄科和蔷薇科苹果亚科（如苹果和梨）中，花粉中两种不同花粉S等位基因的共存会打破花粉的SI，这种现象称为竞争相互作用。然而，竞争相互作用似乎不会在蔷薇科李亚科（如樱桃和杏仁）中发生。此外，花粉S缺失的影响在不同分类群中似乎也有所不同。本综述重点关注蔷薇科苹果亚科和李亚科花粉部分功能的潜在差异，并讨论基于S-RNase的SI机制差异的影响。
