SALICYLIC ACID AS AN ATTENUATOR OF SALT STRESS IN SOURSOP

ABSTRACT The search for alternatives that enable the use of saline waters in agriculture has become constant. In this context, the objective was to evaluate the effects of salicylic acid in mitigating salt stress effects on the growth and gas exchange of soursop cv. ‘Morada Nova’. The study was conducted in a greenhouse, in the municipality of Campina Grande - PB, Brazil. Treatments were distributed in randomized blocks, in a 5 x 4 factorial arrangement, corresponding to five levels of electrical conductivity of irrigation water - ECw (0.8; 1.6; 2.4; 3.2 and 4.0 dS m-1) and four concentrations of salicylic acid - SA (0; 1.2; 2.4 and 3.6 mM), with three replicates. Irrigation with saline water compromised the growth and gas exchange of soursop cv. ‘Morada Nova’. However, exogenous application of salicylic acid induced tolerance to salt stress in soursop plants, as their growth, transpiration, stomatal conductance, photosynthesis and instantaneous carboxylation efficiency were favored by the application of salicylic acid, even when exposed to water salinity.

摘要 探索可应用于农业生产的咸水利用替代方案已成为持续的研究方向。在此背景下，本研究旨在评估水杨酸（salicylic acid, SA）对盐胁迫下‘莫拉达诺瓦’品种刺果番荔枝（soursop）生长与气体交换特性的缓解效果。试验于巴西帕拉伊巴州坎皮纳格兰德市的温室中开展，处理采用5×4因子组合的随机区组设计，设置5个灌溉水电导率（electrical conductivity of irrigation water, ECw）水平（0.8、1.6、2.4、3.2和4.0 dS·m⁻¹）以及4个水杨酸浓度（0、1.2、2.4和3.6 mM），每个处理设置3次重复。咸水灌溉会抑制‘莫拉达诺瓦’刺果番荔枝的生长与气体交换特性；但外源施加水杨酸可诱导该植株产生盐胁迫耐受性，即便处于高盐度灌溉水环境下，水杨酸施加仍可促进植株生长、蒸腾作用、气孔导度、光合作用及瞬时羧化效率。