Soil salinity, together with zinc (Zn) and manganese (Mn) deficiencies, adversely affects rice growth and yield. The comparative salinity stress mitigation response of rice to Zn or Mn remains largely unknown. Rice cultivars, viz. Basmati-515 and KSK-282, were grown in saline soil having electrical conductivity (EC) of 7.5 dS m−1 (as control) parallel to EC 7.5 dS m−1 + Zn 3.5 mg kg−1 and EC 7.5 dS m−1 + Mn 3.5 mg kg−1 treatments in a pot experiment. Application of Zn in saline soil decreased (p < 0.05) sodium (Na+) and chloride (Cl−) concentrations (6% and 26%, respectively) and increased potassium (K+) concentration (25.9%) in leaves compared with the control. The increments in superoxide dismutase (SOD), glutathione reductase (GR), and catalase activities (CAT) reduced salinity-induced oxidative damage which translated into 50.5% and 74% increased membrane stability index (MSI) and relative water content (RWC), respectively. A 5-fold increment of Zn in soil solution ensured its adequate availability for rice which increased SPAD value for an effective photosynthesis to reinforce above ground biomass and grain production. The enhancements in indole-3-acetic acid (46% and 39%) whereas reductions in abscisic acid (18% and 11%) in shoot and root highlighted the Zn-dependent mitigation of salinity stress in both rice cultivars. Ameliorative effect of Mn remained second to Zn despite the increased shoot Mn concentration in KSK-282. Conclusively, both rice cultivars preferred Zn to mitigate salinity; however, KSK-282 responded better through increased antioxidant activities, indole-3-acetic acid biosynthesis, and decreased abscisic acid accumulation.

中文翻译：

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两个水稻 (Oryza sativa L.) 栽培品种对施用锌和锰缓解盐胁迫的比较反应

土壤盐分，连同锌 (Zn) 和锰 (Mn) 的缺乏，会对水稻的生长和产量产生不利影响。水稻对锌或锰的相对盐分胁迫缓解反应在很大程度上仍然未知。水稻品种，即。Basmati-515 和 KSK-282 生长在与 EC 7.5 dS m-1 + Zn 3.5 mg kg-1 和 EC 7.5 dS m- 平行的盐渍土中，其电导率 (EC) 为 7.5 dS m-1（作为对照）盆栽实验中的 1 + Mn 3.5 mg kg−1 处理。与对照相比，在盐渍土中施用锌降低（p < 0.05）钠（Na+）和氯（Cl-）浓度（分别为 6% 和 26%）并增加钾（K+）浓度（25.9%）。超氧化物歧化酶 (SOD)、谷胱甘肽还原酶 (GR) 和过氧化氢酶活性 (CAT) 的增加减少了盐度诱导的氧化损伤，转化为 50。5% 和 74% 分别增加了膜稳定性指数 (MSI) 和相对水含量 (RWC)。土壤溶液中锌的 5 倍增加确保了其对水稻的充足可用性，从而增加了 SPAD 值以进行有效的光合作用，以加强地上生物量和粮食生产。吲哚-3-乙酸的增加（46% 和 39%），而地上部和根中脱落酸（18% 和 11%）的减少突出了两种水稻品种中锌依赖性盐分胁迫的缓解。尽管 KSK-282 中枝条 Mn 浓度增加，但 Mn 的改善作用仍然仅次于 Zn。结论是，两个水稻品种都喜欢用锌来减轻盐度；然而，KSK-282 通过增加抗氧化活性、吲哚-3-乙酸生物合成和减少脱落酸积累而做出更好的反应。