College of Agriculture and Biology of Liaocheng University, Liaocheng 252000, China.
College of Agriculture and Biology of Liaocheng University, Liaocheng 252000, China; Institute of Huanghe Studies, Liaocheng University, Liaocheng 252000, China.
Plant Sci. 2024 Dec;349:112282. doi: 10.1016/j.plantsci.2024.112282. Epub 2024 Oct 9.
Anthocyanins are water-soluble natural pigments found broadly in plants. As members of the flavonoid family, they are widely distributed in various tissues and organs, including roots, leaves, and flowers, responsible for purple, red, blue, and orange colors. Beyond pigmentation, anthocyanins play a role in plant propagation, stress response, defense mechanisms, and human health benefits. Anthocyanin biosynthesis involves a series of conserved enzymes encoded by structural genes regulated by various transcription factors. In rice, anthocyanin-mediated pigmentation serves as an important morphological marker for varietal identification and purification, a critical nutrient source, and a key trait in studying rice domestication. Anthocyanin biosynthesis in rice is regulated by a ternary conserved MBW transcriptional complexes comprising MYB transcription factors (TFs), basic-helix-loop-helix (bHLH) TFs, and WD40 repeat protein, which activate the expression of structure genes. Wild rice (Oryza rufipogon) commonly has purple hull, purple stigma, purple apiculus, purple leaf, and red pericarp due to the accumulations of anthocyanin or proanthocyanin. However, most cultivated rice (Oryza sativa) varieties lose the anthocyanin phenotypes due to the function variations of some regulators including OsC1, OsRb, and Rc and the structure gene OsDFR. Over the past decades, significant progress has been made in understanding the molecular and genetic mechanisms of anthocyanin biosynthesis. This review summarizes research progress in rice anthocyanin biosynthetic pathways, genes involvements, distribution regulations, and domestication processes. Furthermore, it discusses future prospects for anthocyanin biosynthesis research in rice, aiming to provide a theoretical foundation for future investigations and applications, and to assist in breeding new rice varieties with organ-targeted anthocyanin deposition.
花色苷是广泛存在于植物中的水溶性天然色素。作为类黄酮家族的成员，它们广泛分布于各种组织和器官中，包括根、叶和花，赋予植物紫色、红色、蓝色和橙色等颜色。除了作为色素外，花色苷还在植物繁殖、应激反应、防御机制和人类健康益处中发挥作用。花色苷的生物合成涉及一系列由结构基因编码的保守酶，这些基因受各种转录因子调控。在水稻中，花色苷介导的色素沉着是品种鉴定和纯化的重要形态标记，是一种重要的营养物质来源，也是研究水稻驯化的关键特征。水稻花色苷的生物合成受一个三元保守的 MBW 转录复合物调控，该复合物由 MYB 转录因子（TFs）、碱性-螺旋-环-螺旋（bHLH）TFs 和 WD40 重复蛋白组成，它们激活结构基因的表达。野生稻（Oryza rufipogon）由于花色苷或原花色素的积累，通常具有紫色谷壳、紫色柱头、紫色颖尖、紫色叶片和红色果皮。然而，由于包括 OsC1、OsRb 和 Rc 在内的一些调节因子以及结构基因 OsDFR 的功能变异，大多数栽培稻（Oryza sativa）品种失去了花色苷表型。在过去的几十年中，人们在理解花色苷生物合成的分子和遗传机制方面取得了重大进展。本综述总结了水稻花色苷生物合成途径、基因参与、分布调控和驯化过程的研究进展。此外，还讨论了水稻花色苷生物合成研究的未来前景，旨在为未来的研究和应用提供理论基础，并协助培育具有器官靶向花色苷沉积的新型水稻品种。
