Department of Plant Agriculture, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON, Canada.
Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC, Canada.
J Pineal Res. 2018 Mar;64(2). doi: 10.1111/jpi.12452. Epub 2018 Jan 11.
Melatonin and serotonin are important signaling and stress mitigating molecules that play important roles across growth and development in plants. Despite many well-documented responses, a systematic investigation of the entire metabolic pathway (tryptophan, tryptamine, and N-acetylserotonin) does not exist, leaving many open questions. The objective of this study was to determine the responses of Hypericum perforatum (L.) to melatonin, serotonin, and their metabolic precursors. Two well-characterized germplasm lines (#4 and 112) created by mutation and a haploid breeding program were compared to wild type to identify specific responses. Germplasm line 4 has lower regenerative and photosynthetic capacity than either wild type or line 112, and there are documented significant differences in the chemistry and physiology of lines 4 and 112. Supplementation of the culture media with tryptophan, tryptamine, N-acetylserotonin, serotonin, or melatonin partially reversed the regenerative recalcitrance and growth impairment of the germplasm lines. Quantification of phytohormones revealed crosstalk between the indoleamines and related phytohormones including cytokinin, salicylic acid, and abscisic acid. We hypothesize that melatonin and serotonin function in coordination with their metabolites in a cascade of phytochemical responses including multiple pathways and phytohormone networks to direct morphogenesis and protect photosynthesis in H. perforatum.
褪黑素和血清素是重要的信号分子和应激缓解分子，在植物的生长和发育过程中发挥着重要作用。尽管有许多有充分记录的反应，但整个代谢途径（色氨酸、色胺和 N-乙酰血清素）的系统研究并不存在，这留下了许多悬而未决的问题。本研究的目的是确定贯叶连翘（L.）对褪黑素、血清素及其代谢前体的反应。通过突变和单倍体育种计划创建的两种特征明确的种质系（#4 和 112）与野生型进行了比较，以确定特定的反应。种质系 4 的再生和光合作用能力低于野生型或系 112，并且在系 4 和 112 的化学和生理学方面有记录的显著差异。在培养基中添加色氨酸、色胺、N-乙酰血清素、血清素或褪黑素部分逆转了种质系的再生抗性和生长障碍。植物激素的定量分析显示，吲哚胺与相关植物激素（包括细胞分裂素、水杨酸和脱落酸）之间存在串扰。我们假设褪黑素和血清素与其代谢物在植物化学物质反应级联中协同作用，包括多个途径和植物激素网络，以指导形态发生并保护贯叶连翘中的光合作用。
