Rouphael Youssef, Kyriacou Marios C
Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy.
Department of Vegetable Crops, Agricultural Research Institute, Nicosia, Cyprus.
Front Plant Sci. 2018 Aug 22;9:1254. doi: 10.3389/fpls.2018.01254. eCollection 2018.
Closed soilless cultivation systems (SCS) support high productivity and optimized year-round production of standardized quality. Efficiency and precision in modulating nutrient solution composition, in addition to controlling temperature, light, and atmospheric composition, renders protected SCS instrumental for augmenting organoleptic and bioactive components of quality. Effective application of eustress (positive stress), such as moderate salinity or nutritional stress, can elicit tailored plant responses involving the activation of physiological and molecular mechanisms and the strategic accumulation of bioactive compounds necessary for adaptation to suboptimal environments. For instance, it has been demonstrated that the application of salinity eustress increases non-structural carbohydrates and health-promoting phytochemicals such as lycopene, β-carotene, vitamin C, and the overall phenolic content of tomato fruits. Salinity eustress can also reduce the concentration of anti-nutrient compounds such as nitrate due to antagonism between nitrate and chloride for the same anion channel. Furthermore, SCS can be instrumental for the biofortification of vegetables with micronutrients essential or beneficial to human health, such as iodine, iron, selenium, silicon, and zinc. Accurate control of microelement concentrations and constant exposure of roots to the fortified nutrient solution without soil interaction can maximize their uptake, translocation, and accumulation in the edible plant parts; however, biofortification remains highly dependent on microelement forms and concentrations present in the nutrient solution, the time of application and the accumulation capacity of the selected species. The present article provides an updated overview and future perspective on scientific advances in SCS aimed at enhancing the sensory and bioactive value of vegetables.
封闭式无土栽培系统（SCS）能实现高产量，并优化全年标准化品质的生产。除了控制温度、光照和大气成分外，调节营养液成分的效率和精准度使受保护的SCS有助于提高品质的感官和生物活性成分。有效施加良性应激（积极应激），如适度的盐分或营养胁迫，可引发特定的植物反应，包括激活生理和分子机制以及战略性积累适应次优环境所需的生物活性化合物。例如，已证明施加盐分良性应激可增加非结构性碳水化合物以及促进健康的植物化学物质，如番茄红素、β-胡萝卜素、维生素C和番茄果实的总酚含量。盐分良性应激还可由于硝酸盐和氯离子对同一阴离子通道的拮抗作用而降低抗营养化合物如硝酸盐的浓度。此外，SCS有助于用对人体健康必不可少或有益的微量营养素对蔬菜进行生物强化，如碘、铁、硒、硅和锌。精确控制微量元素浓度以及使根系持续接触强化营养液而不与土壤相互作用，可最大限度地提高其在可食用植物部分的吸收、转运和积累；然而，生物强化仍高度依赖于营养液中微量元素的形态和浓度、施用时间以及所选物种的积累能力。本文提供了关于SCS科学进展的最新综述和未来展望，旨在提高蔬菜的感官和生物活性价值。
