Unité Mixte de Recherche, Institut National de la Recherche Agronomique, 1131 Santé de la Vigne et Qualité du Vin, F-68021 Colmar, France.
Plant Physiol. 2012 Nov;160(3):1407-19. doi: 10.1104/pp.112.202705. Epub 2012 Sep 6.
Stilbenes are a small family of phenylpropanoids produced in a number of unrelated plant species, including grapevine (Vitis vinifera). In addition to their participation in defense mechanisms in plants, stilbenes, such as resveratrol, display important pharmacological properties and are postulated to be involved in the health benefits associated with a moderate consumption of red wine. Stilbene synthases (STSs), which catalyze the biosynthesis of the stilbene backbone, seem to have evolved from chalcone synthases (CHSs) several times independently in stilbene-producing plants. STS genes usually form small families of two to five closely related paralogs. By contrast, the sequence of grapevine reference genome (cv PN40024) has revealed an unusually large STS gene family. Here, we combine molecular evolution and structural and functional analyses to investigate further the high number of STS genes in grapevine. Our reannotation of the STS and CHS gene families yielded 48 STS genes, including at least 32 potentially functional ones. Functional characterization of nine genes representing most of the STS gene family diversity clearly indicated that these genes do encode for proteins with STS activity. Evolutionary analysis of the STS gene family revealed that both STS and CHS evolution are dominated by purifying selection, with no evidence for strong selection for new functions among STS genes. However, we found a few sites under different selection pressures in CHS and STS sequences, whose potential functional consequences are discussed using a structural model of a typical STS from grapevine that we developed.
芪类化合物是一类由许多不同植物物种（包括葡萄藤[Vitis vinifera]）产生的苯丙烷类化合物。除了参与植物的防御机制外，芪类化合物（如白藜芦醇）还具有重要的药理学特性，并被认为与适量饮用红酒相关的健康益处有关。芪合酶（STSs）催化芪类化合物的生物合成，似乎在产生芪类化合物的植物中已经独立地从查尔酮合酶（CHSs）进化而来多次。STSs 基因通常形成两个到五个密切相关的同源基因的小家族。相比之下，葡萄参考基因组（cv PN40024）的序列揭示了一个异常庞大的 STS 基因家族。在这里，我们结合分子进化和结构与功能分析，进一步研究葡萄中大量 STS 基因的情况。我们对 STS 和 CHS 基因家族的重新注释产生了 48 个 STS 基因，其中至少有 32 个是潜在功能基因。对代表 STS 基因家族多样性的 9 个基因的功能特征分析清楚地表明，这些基因确实编码具有 STS 活性的蛋白质。STS 基因家族的进化分析表明，STS 和 CHS 的进化都受到纯化选择的支配，没有证据表明 STS 基因具有新功能的强烈选择。然而，我们在 CHS 和 STS 序列中发现了一些受到不同选择压力的位点，我们使用从葡萄中开发的典型 STS 的结构模型讨论了其潜在的功能后果。
