Universidade Federal de Campina Grande, Programa de Pós-Graduação em Engenharia Agrícola, Campina Grande, PB, Brasil.
Universidade Estadual da Paraíba, Programa de Pós-Graduação em Ciências Agrárias, Campina Grande, PB, Brasil.
Braz J Biol. 2024 Aug 5;84:e282616. doi: 10.1590/1519-6984.282616. eCollection 2024.
Salt stress causes several physiological and biochemical disorders and impairs plant growth. However, adequate fertilization can improve the nutritional status and may reduce significantly the harmful effects caused by salt stress. From this perspective, this study aimed to evaluate the impact of different combinations of nitrogen, phosphorus and potassium fertilization on the antioxidant activity and accumulation of organic and inorganic solutes in West Indian cherry leaves, in the second year of production. The experimental design was in randomized blocks, with treatments distributed in a 10 × 2 factorial arrangement corresponding to ten fertilization combinations (FC) of NPK (FC1: 80-100-100%, FC2:100-100-100%, FC3:120-100-100%, FC4:140-100-100%, FC5:100-80-100%, FC6:100-120-100%, FC7:100-140-100%, FC8:100-100-80%, FC9:100-100-120%, and FC10:100-100-140% of the recommendation) and two levels of electrical conductivity of irrigation water (ECw) (0.6 and 4.0 dS m-1), with three replications. The multivariate analysis showed that irrigation with water of different electrical conductivities (0.6 and 4.0 dS m-1) resulted in different responses concerning the enzyme activity, production of organic compounds, and accumulation of inorganic solutes in the leaves. Under irrigation with low salinity water, there was greater accumulation of K+, soluble carbohydrates, and proline, and lower activity of antioxidative enzymes, especially SOD and APX. Under high salinity water, greater enzyme activity and higher concentrations of Na+ and Cl- were observed. The results indicate that the response of West Indian cherry to salinity was more towards redox homeostasis than osmotic homeostasis through the accumulation of compatible solutes. Fertilization combination FC5 (100-80-100% corresponding to 200, 24 and 80 g plant-1 of NPK) modulates the enzyme activity of SOD and APX attenuating the impacts of salinity, being an efficient combination to preserve redox homeostasis in West Indian cherry plants grown under salt stress.
盐胁迫会导致多种生理和生化紊乱，从而损害植物生长。然而，适当的施肥可以改善营养状况，并可能显著减轻盐胁迫造成的有害影响。从这个角度来看，本研究旨在评估不同氮、磷、钾施肥组合对西印度樱桃叶片抗氧化活性和有机、无机溶质积累的影响，这是生产的第二年。试验设计采用随机区组设计，处理分布在 10×2 因子组合中，对应于 10 种氮磷钾施肥组合（FC）（FC1：80-100-100%，FC2：100-100-100%，FC3：120-100-100%，FC4：140-100-100%，FC5：100-80-100%，FC6：100-120-100%，FC7：100-140-100%，FC8：100-100-80%，FC9：100-100-120%，FC10：100-100-140%的推荐量）和两个灌溉水电导率（ECw）水平（0.6 和 4.0 dS m-1），每个处理重复 3 次。多元分析表明，不同电导率（0.6 和 4.0 dS m-1）的灌溉水导致叶片中酶活性、有机化合物产生和无机溶质积累的不同反应。在低盐度水灌溉下，K+、可溶性碳水化合物和脯氨酸积累较多，抗氧化酶活性，特别是 SOD 和 APX 活性较低。在高盐度水灌溉下，观察到更高的酶活性和更高浓度的 Na+和 Cl-。结果表明，西印度樱桃对盐度的反应更倾向于通过积累相容性溶质来维持氧化还原平衡，而不是渗透平衡。施肥组合 FC5（100-80-100%对应于 200、24 和 80 g 植物-1 的 NPK）调节 SOD 和 APX 的酶活性，减轻盐度的影响，是在盐胁迫下保持西印度樱桃植物氧化还原平衡的有效组合。
