Murch Susan J, Erland Lauren A E
Department of Chemistry, University of British Columbia, Kelowna, BC, Canada.
Front Plant Sci. 2021 Jun 18;12:683047. doi: 10.3389/fpls.2021.683047. eCollection 2021.
Melatonin (N-acetyl-5-methoxy-tryptamine) is a mammalian neurohormone, antioxidant and signaling molecule that was first discovered in plants in 1995. The first studies investigated plant melatonin from a human perspective quantifying melatonin in foods and medicinal plants and questioning whether its presence could explain the activity of some plants as medicines. Starting with these first handful of studies in the late 1990s, plant melatonin research has blossomed into a vibrant and active area of investigation and melatonin has been found to play critical roles in mediating plant responses and development at every stage of the plant life cycle from pollen and embryo development through seed germination, vegetative growth and stress response. Here we have utilized a systematic approach in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocols to reduce bias in our assessment of the literature and provide an overview of the current state of melatonin research in plants, covering 1995-2021. This review provides an overview of the biosynthesis and metabolism of melatonin as well as identifying key themes including: abiotic stress responses, root development, light responses, interkingdom communication, phytohormone and plant signaling. Additionally, potential biases in the literature are investigated and a birefringence in the literature between researchers from plant and medical based which has helped to shape the current state of melatonin research. Several exciting new opportunities for future areas of melatonin research are also identified including investigation of non-crop and non-medicinal species as well as characterization of melatonin signaling networks in plants.
褪黑素（N-乙酰-5-甲氧基色胺）是一种哺乳动物神经激素、抗氧化剂和信号分子，于1995年首次在植物中被发现。最初的研究从人类视角出发，对食物和药用植物中的褪黑素进行定量分析，并质疑其存在是否可以解释某些植物作为药物的活性。从20世纪90年代末的这几项初步研究开始，植物褪黑素研究已发展成为一个充满活力且活跃的研究领域，并且发现褪黑素在介导植物生命周期各个阶段的反应和发育过程中发挥着关键作用，从花粉和胚胎发育到种子萌发、营养生长和应激反应。在此，我们采用了一种系统的方法，按照系统评价和荟萃分析的首选报告项目（PRISMA）方案，以减少我们对文献评估中的偏差，并概述1995年至2021年植物褪黑素研究的现状。本综述概述了褪黑素的生物合成和代谢，同时确定了关键主题，包括：非生物胁迫反应、根系发育、光反应、跨界通讯、植物激素和植物信号传导。此外，还研究了文献中可能存在的偏差，以及植物学和医学领域研究人员之间文献的双折射现象，这有助于塑造当前褪黑素研究的现状。还确定了未来褪黑素研究领域的几个令人兴奋的新机会，包括对非作物和非药用物种的研究以及植物中褪黑素信号网络的表征。
