Nitric oxide donors and gallic acid effects on amelioration of heat stress on heat shock protein 70.1 (HSP-70.1) expression and physiological traits in Vicia faba

Heat stress is a challenge for crop production worldwide, leading to a reduction in plant growth and productivity. Faba bean is a valuable crop because of its nutritional value and free nitrogen fixation capacity. This research focused on the potential of nitric oxide (NO) donors, specifically arginine (Arg) and sodium nitroprusside (SNP), along with gallic acid (GA), and their combinations (Arg-GA and SNP-GA), on the performance of faba beans under heat stress. The described treatments led to an increase in HSP-70.1 expression, surpassing the levels observed in plants subjected to heat stress alone. This resulted in a significant increase in proteins, which means proteins stability. Heat stress increased H₂O₂, which was accompanied by increased activity of catalase and ascorbate peroxidase, as well as lipid peroxidation. Treatment with SNP, Arg and GA, alone or in combination, effectively reduced oxidative stress. Increased enzymatic and non-enzymatic antioxidants (phenols, carotenoids, and proline) reduced lipid membrane peroxidation and photosynthetic pigments damage. The effect of these treatments may vary according to the specific parameters being measured. In faba beans, NO donors generally were more effective than GA alone at alleviating stress, with SNP being a particularly potent NO donor for this purpose. The interaction between NO donors and GA enhanced its efficiency, but further research is needed to fully understand mechanisms behind this. Overall, exogenous application of NO is a promising strategy for mitigating the negative effects of heat stress, minimizing heat-induced damage and improving plant survival.