Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074, China.
Graduate University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China.
Sci Rep. 2016 Jun 30;6:29153. doi: 10.1038/srep29153.
Sugars play a variety of roles in plants, and their accumulation in seeds and/or surrounding pericarp tissues is distinctly different between grasses and eudicots. However, little is known about the evolutionary pattern of genes involved in sugar accumulation in these two major groups of flowering plants. Here, we compared evolutionary rates, gene duplication, and selective patterns of genes involved in sugar metabolism and transport between grasses and eudicots using six grass species and seven eudicot species as materials. Overall, sugar transporter genes exhibit divergent evolutionary patterns, whereas, sugar metabolism genes showing similar evolutionary pattern between monocots and eudicots. Sugar transporter genes have higher frequencies of recent duplication in eudicots than in grasses and their patterns of evolutionary rate are different. Evidence for divergent selection of these two groups of flowering plants is also observed in sugar transporter genes, wherein, these genes have undergone positive selection in eudicots, but not in grasses. Taken together, these findings suggest that sugar transporter genes rather than sugar metabolism genes play important roles in sugar accumulation in plants, and that divergent evolutionary patterns of sugar transporter genes are associated with the difference of sugar accumulation in storage tissues of grasses and eudicots.
糖在植物中扮演着多种角色，其在种子和/或周围的种皮组织中的积累在禾本科和真双子叶植物之间有明显的不同。然而，关于这两大类开花植物中参与糖积累的基因的进化模式知之甚少。在这里，我们使用六种禾本科植物和七种真双子叶植物作为材料，比较了糖代谢和运输相关基因在禾本科和真双子叶植物中的进化速率、基因复制和选择模式。总的来说，糖转运蛋白基因表现出不同的进化模式，而糖代谢基因在单子叶植物和真双子叶植物之间表现出相似的进化模式。与禾本科植物相比，真双子叶植物中糖转运蛋白基因的近期复制频率更高，其进化速率模式也不同。在糖转运蛋白基因中也观察到了这两组开花植物的分歧选择证据，其中，这些基因在真双子叶植物中经历了正选择，但在禾本科植物中没有。总之，这些发现表明，糖转运蛋白基因而不是糖代谢基因在植物的糖积累中起着重要作用，糖转运蛋白基因的不同进化模式与禾本科和真双子叶植物的贮藏组织中糖积累的差异有关。
