Enhancement of health-promoting and plant-protecting secondary metabolites by postharvest conditioning with hormetic doses of abiotic stresses

我们的长期目标是开发采后调理技术，以提高新鲜水果和蔬菜中促进健康(营养食品)和植物保护(植物保健素)的次生代谢物，使用适合于采后阶段应用的适当剂量的非生物胁迫。鉴于植物产生次生代谢物作为对抗压力的武器，有可能很好地调整这种反应，以在增强提供植物保护和健康益处的膳食植物化学物质与通过将产品暴露于受控剂量的应激源而使产品可接受之间实现平衡。这将需要更好地了解应激源和次生代谢物之间的联系，并了解应激诱导的次生代谢物和代谢途径的变化。因此，我们在短期到中期的努力将集中在了解非生物应激源、信号成分和次生代谢物产生的节律剂量之间的联系。这项研究涉及：(1)确定所选作物中非生物胁迫的节律剂量；(2)在不影响产品感官品质的情况下有效地诱导或增强所需次生代谢物的节律胁迫；(3)所选非生物胁迫及其组合在所选作物中产生氧化还原和激素信号的特征；(4)在暴露于所选胁迫及其组合中的作物中产生所需植物化学物质的次生代谢物的特征；(5)建立信号成分与次生代谢物之间的相关关系，有助于确定影响植物化学物质生产的关键信号成分(S)。研究将对胡萝卜根和西红柿果实进行。富含植物化学物质的新鲜水果和蔬菜最近被确定为一类新的功能食品。保藏具有促进健康和抗病能力的新鲜作物，不仅有助于生鲜农产品行业减少采后损失，还有助于确保更健康的人口。

Our long-term goal is to develop post-harvest conditioning technologies to enhance health-promoting (nutraceutical) and plant-protecting (phytoalexin) secondary metabolites in fresh fruits and vegetables using hormetic doses of abiotic stresses that are suitable for application in the postharvest phase. Given that plants produce secondary metabolites as weapons to combat stresses, it is possible that the response can well be tuned to achieve a balance between enhancement of dietary phytochemicals that offer plant protection and health benefits and acceptability of the produce by exposing them to controlled doses of stressors. This would require a better understanding of the link between stressors and secondary metabolites, and an understanding of the stress-induced alterations in the secondary metabolites and metabolic pathways. Thus our efforts in the short- to medium-term will be focused on gaining an understanding of the connections between hormetic doses of abiotic stressors, signal components and secondary metabolite production. The research involves: (1) the determination of hormetic doses of abiotic stresses in selected crops; (2) the selection of hormetic stresses which are effective in inducing or enhancing desired secondary metabolites without affecting sensory quality of the produce; (3) the characterization of the selected abiotic stresses and their combinations for their generation of redox and hormonal signals in the selected crops; (4) the profiling of secondary metabolites of the pathways that produce the desired phytochemicals in the crops exposed to the selected stresses and their combinations; and (5) the establishment of correlative relationships between signal components and secondary metabolites which will help identify key signal component(s) that impact the production of desired phytochemicals. Studies will be performed with carrot root and tomato fruit. Phytochemical-enriched fresh fruits and vegetables have recently been identified as a new class of functional foods. Preservation of fresh crops with enhanced attributes of health-promotion and disease resistance will not only help the fresh produce industry to reduce postharvest losses, but also help them to ensure a healthier population.