Department of Horticultural Science, Faculty of Agriculture, University of Maragheh, Maragheh, Iran.
Agricultural Biotechnology Research Institute of Iran - Isfahan Branch, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.
Plant Physiol Biochem. 2020 Apr;149:313-323. doi: 10.1016/j.plaphy.2020.02.021. Epub 2020 Feb 15.
The increasing salinity in soils and irrigation water is a major concern for growers of strawberry, a salt-sensitive horticultural crop. The hormone melatonin (N-acetyl-5-methoxytryptamine) is involved in many biological processes and affects plant responses to environmental stresses. The effects of weekly 100 and 200 μM melatonin sprays on leaf composition parameters (photosynthetic pigment and macronutrient concentrations, oxidative stress markers, antioxidant defense systems and abscisic acid concentrations), fruit yield and quality parameters (soluble solids, total acidity, ascorbic acid, total antioxidants and phenolics and sugars), and leaf and fruit melatonin have been studied in strawberry grown under non-saline, moderate and intense salinity conditions (0, 40 and 80 mM NaCl, respectively). Salinity led to decreases in yield, fruit quality parameters and leaf photosynthetic pigments and macronutrient concentrations, as well as to increases in oxidative stress, with melatonin foliar application alleviating all these changes. On the other hand, salinity led to increases in the leaf levels of antioxidant enzymes, abscisic acid and melatonin, with foliar applications of melatonin boosting those increases. In the absence of salinity stress, melatonin led to smaller changes in all parameters in the same direction to that observed in the presence of salinity. Furthermore, melatonin resulted in increases in strawberry fruit yield and quality, especially in plants grown under salinity. Results indicate that the effects of melatonin application are associated with a boost in leaf antioxidant enzymes and abscisic acid, and support that the application of melatonin is a promising tool for mitigating salt stress in strawberry.
土壤和灌溉水中盐度的增加是草莓种植者的主要关注点，草莓是一种对盐分敏感的园艺作物。褪黑素（N-乙酰-5-甲氧基色胺）是一种参与许多生物过程的激素，它影响植物对环境胁迫的反应。每周喷洒 100 和 200 μM 褪黑素对叶片组成参数（光合色素和大量营养素浓度、氧化应激标志物、抗氧化防御系统和脱落酸浓度）、果实产量和质量参数（可溶性固体、总酸度、抗坏血酸、总抗氧化剂和酚类以及糖）以及叶片和果实褪黑素的影响，在非盐渍、中度和重度盐渍条件下（分别为 0、40 和 80 mM NaCl）种植的草莓中进行了研究。盐度导致产量、果实质量参数和叶片光合色素和大量营养素浓度下降，氧化应激增加，而叶面施用褪黑素缓解了所有这些变化。另一方面，盐度导致叶片抗氧化酶、脱落酸和褪黑素水平升高，叶面施用褪黑素促进了这些升高。在没有盐胁迫的情况下，褪黑素导致所有参数朝着与盐胁迫下相同的方向发生较小的变化。此外，褪黑素增加了草莓果实的产量和质量，尤其是在盐分条件下生长的植物。结果表明，褪黑素应用的效果与叶片抗氧化酶和脱落酸的增强有关，并支持应用褪黑素是缓解草莓盐胁迫的一种有前途的工具。
