It is known that auxin and nitric oxide have the ability to ameliorate various abiotic stresses in plants individually. However, their interactive effects on the stress generated by salt in plants are not reported yet. Therefore, the present study was conducted to explore the effectiveness of sodium nitroprusside (SNP), a donor of nitric oxide and IAA (Indole acetic acid) individually and in combination on the photosynthetic efficiency, antioxidative enzyme activities, and plant biomass under salt stress. Twenty-five-day-old plants were exposed to SNP and IAA individually and in combination for 5 days continuously, and it was found that both SNP and IAA showed almost similar response at 30 and 45 days of old plants and increased studied parameters over their respective controls. However, the interactive effect of both SNP and IAA excelled over the individual response of SNP and IAA. On the other hand, the presence of salt in soil significantly decreased the parameters studied. Furthermore, stress generated by NaCl was overcome by the exogenous application of SNP, IAA alone as well as in combination at both the stages of samplings. However, the combination of IAA and SNP was more effective at 45 DAS where the value of plant biomass and photosynthetic efficiency was more in comparison to control plants. The level of antioxidant enzymes and proline was further enhanced by SNP and IAA and maximum values were reported in the plants received both SNP and IAA under NaCl stress. This enhanced antioxidant system and proline accumulation could ameliorate the stress induced by NaCl in plants that was reflected by the improved plant biomass, and photosynthetic efficiency in comparison to control plants.

中文翻译：

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生长素和一氧化氮相互作用提高盐胁迫下芥菜植物的光合效率和抗氧化系统

众所周知，生长素和一氧化氮能够单独缓解植物中的各种非生物胁迫。然而，它们对植物盐分胁迫的交互作用尚未见报道。因此，本研究旨在探讨硝普钠（SNP）（一氧化氮和 IAA（吲哚乙酸）的供体）单独和组合对盐胁迫下光合效率、抗氧化酶活性和植物生物量的有效性。将 25 天大的植物单独和组合暴露于 SNP 和 IAA 连续 5 天，发现 SNP 和 IAA 在 30 天和 45 天的老植物中表现出几乎相似的响应，并且研究参数增加了各自的控制。然而，SNP 和 IAA 的交互作用优于 SNP 和 IAA 的个体反应。另一方面，土壤中盐分的存在显着降低了所研究的参数。此外，通过外源性应用 SNP、IAA 以及在两个采样阶段的组合，可以克服 NaCl 产生的压力。然而，IAA 和 SNP 的组合在 45 DAS 时更有效，与对照植物相比，植物生物量和光合效率的值更高。SNP和IAA进一步增强了抗氧化酶和脯氨酸的水平，并且在NaCl胁迫下同时接受SNP和IAA的植物中报告了最大值。这种增强的抗氧化系统和脯氨酸积累可以改善 NaCl 诱导的植物胁迫，这反映在植物生物量的改善上，