Department of Horticulture and Landscape Architecture, Purdue University, IN, USA.
Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, USA.
J Exp Bot. 2021 Feb 2;72(2):167-176. doi: 10.1093/jxb/eraa462.
Plant 1,4-naphthoquinones encompass a class of specialized metabolites known to mediate numerous plant-biotic interactions. This class of compounds also presents a remarkable case of convergent evolution. The 1,4-naphthoquinones are synthesized by species belonging to nearly 20 disparate orders spread throughout vascular plants, and their production occurs via one of four known biochemically distinct pathways. Recent developments from large-scale biology and genetic studies corroborate the existence of multiple pathways to synthesize plant 1,4-naphthoquinones and indicate that extraordinary events of metabolic innovation and links to respiratory and photosynthetic quinone metabolism probably contributed to their independent evolution. Moreover, because many 1,4-naphthoquinones are excreted into the rhizosphere and they are highly reactive in biological systems, plants that synthesize these compounds also needed to independently evolve strategies to deploy them and to resist their effects. In this review, we highlight new progress made in understanding specialized 1,4-naphthoquinone biosynthesis and trafficking with a focus on how these discoveries have shed light on the convergent evolution and diversification of this class of compounds in plants. We also discuss how emerging themes in metabolism-based herbicide resistance may provide clues to mechanisms plants employ to tolerate allelopathic 1,4-naphthoquinones.
植物 1,4-萘醌类化合物包含一类专门的代谢物，已知这些代谢物介导了许多植物与生物的相互作用。这一类化合物也呈现出显著的趋同进化现象。1,4-萘醌类化合物由属于近 20 个不同目且广泛分布于维管植物中的物种合成，其合成途径有四种，且在生化上各不相同。大规模生物学和遗传学研究的最新进展证实了植物 1,4-萘醌类化合物的多种合成途径的存在，并表明代谢创新的非凡事件以及与呼吸和光合醌代谢的联系可能促成了它们的独立进化。此外，由于许多 1,4-萘醌类化合物被分泌到根际，并且在生物系统中具有高度反应性，因此合成这些化合物的植物也需要独立进化出使用它们和抵抗它们影响的策略。在这篇综述中，我们强调了在理解专门的 1,4-萘醌生物合成和运输方面取得的新进展，重点介绍了这些发现如何阐明了这一类化合物在植物中的趋同进化和多样化。我们还讨论了基于代谢的除草剂抗性的新兴主题如何为植物耐受化感 1,4-萘醌类化合物的机制提供线索。
