The modification in quality of parsley (Petroselinum crispum) by selenium and amino acids

This research was conducted with the purpose of appraising the effect of Selenium (Se) and/or amino acid fertilizers (AA) on improving growth, physiology, and biofortification of parsley grown under high EC condition. Plants were foliarly supplemented with four levels of Se (0, 25, 50, 100 mgl-1) and/or two concentrations of AA (0 and 0.2%) three times with a week interval. The significantly increases in the leaf fresh and dry masses as well as improvements in leaf area and stem heights were recorded in Se and/or AA-supplemented plants, as opposed to Se 100. However, the growth inhibiting effects of Se 100 were relieved by AA. In contrast to Se 100, Se 25 AA and Se 50 AA were the most effective treatments to improve the chlorophyll contents. The significant inductions in the activities of antioxidant enzymes, peroxidase, and polyphenol oxidase were observed in Se and/or AA treated plants. The usage of Se and/or AA, especially the combined ones, led to the significant stimulations in the activities of phenylalanine ammonia lyase (PAL). The significantly higher contents of phenolics, a suitable quality indicator with great significance for cardiovascular diseases in humans, were observed in Se and/or AA supplemented plants. The foliar supplementation of amino acids accelerated and/or declined the physiological alterations triggered by Se dependent on the applied concentrations. It could be concluded that the simultaneous supplementation of Se and AA at appropriate levels represents an environmentally friendly way of promoting growth, alleviating stress, and fortifying in parsley.