Mitigation of heat stress in wheat (Triticum aestivum L.) via regulation of physiological attributes using sodium nitroprusside and gibberellic acid

Abstract

Heat stress poses a threat to plants in arid and semiarid regions, leading to soil salinization and plant mortality. Researchers are exploring remedies to alleviate these effects, including using gibberellic acid (GA3) to regulate plant enzymes and antioxidants. Additionally, sodium nitroprusside (SNP) is gaining attention, but its combined effect with GA3 requires further research. To address this gap, we investigated the effects of GA3 and SNP on plants under heat stress conditions. For that, wheat plants were cultivated under 40 °C for 6 h per day (15 days). Sodium nitroprusside (donor of NO and SNP) and gibberellic acid (GA3), respectively, with 100 µM and 5 µg/ml concentrations, were applied as foliar sprays at 10 days after sowing (DAS). Results showed that SNP + GA3 treatment had the highest plant height (4.48% increase), plant fresh weight (29.7%), plant dry weight (87%), photosynthetic rate (39.76%) and stomatal conductance (38.10%), and Rubisco (54.2%) compared to the control. Our findings indicate a significant increase in NO, H₂O₂, TBARS, SOD, POD, APX, proline, GR, and GB that greatly scavenged reactive oxygen species (ROS) for decreasing the adverse effect of stress. Such findings confirmed the efficacy of the combined treatment of SNP + GA3 under high-temperature stress compared to the solitary application of GA3, SNP, and control. In conclusion, using SNP + GA3 is a better strategy for mitigating heat stress in wheat than individual applications. Further research is recommended to validate the effectiveness of SNP + GA3 in other cereal crops.