Nitric Oxide Increases the Physiological and Biochemical Stability of Soybean Plants under High Temperature

Abstract

Thermal stress reduces plant growth and development, resulting in considerable economic losses in crops such as soybeans. Nitric oxide (NO) in plants is associated with tolerance to various abiotic stresses. Nevertheless, there are few studies of the range of observed effects of NO in modulating physiological and metabolic functions in soybean plants under high temperature. In the present study, we investigated the effects of sodium nitroprusside (SNP, NO donor), on anatomical, physiological, biochemical, and metabolic processes of soybean plants exposed to high temperature. Soybean plants were grown in soil: sand (2:1) substrate in acclimatized growth chambers. At developmental V3 stage, plants were exposed to two temperatures (25 °C and 40 °C) and SNP (0 and 100 μM), in a randomized block experimental design, with five replicates. After six days, we quantified NO concentration, leaf anatomy, gas exchange, chlorophyll a fluorescence, photosynthetic pigments, lipid peroxidation, antioxidant enzyme activity, and metabolite profiles. Higher NO concentration in soybean plants exposed to high temperature and SNP showed increased effective quantum yields of photosystem II (PSII) and photochemical dissipation, thereby maintaining the photosynthetic rate. Under high temperature, NO also promoted greater activity of ascorbate peroxidase and peroxidase activity, avoiding lipid peroxidation of cell membranes, in addition to regulating amino acid and organic compound levels. These results suggest that NO prevented damage caused by high temperature in soybean plants, illustrating the potential to mitigate thermal stress in cultivated plants.

Role of Exogenous Melatonin, Hydrogen Sulfide and Nitric Oxide on Organic Acid Content of Eruca sativa L. under Salt Stress

“…The findings of our study also confirmed the beneficial effects of hydrogen sulfide and nitric oxide under salinity stress. These results are confirmed by the findings of Vital et al [16] according to them nitric oxide regulated the organic acid and amino acids of soybean plants under high temperature.…”

Can light intensity modulate the physiological, anatomical, and reproductive responses of soybean plants to water deficit?

“…This enzyme acts on the decomposition of H 2 O 2 , using it as an acceptor of electrons from the oxidation of phenolic compounds (Jóźwiak & Politycka, 2019). Vital et al (2019) found, in an experiment with the same soybean cultivar as in this study, an increase in POX activity, however, due to high temperature stress. Taken together, the photoprotective role of the antioxidant system of soybean plants stands out, due mainly to the HI condition, as evidenced by the greater activity of CAT, APX, SOD, and POX, without reduction of A .…”

Nitric Oxide Enhances Photosynthetic Nitrogen and Sulfur-Use Efficiency and Activity of Ascorbate-Glutathione Cycle to Reduce High Temperature Stress-Induced Oxidative Stress in Rice (Oryza sativa L.) Plants

“…Application of SNP resulted in the alleviation of high temperature stress-induced effects on net photosynthesis and maximal PSII photochemical efficiency. In several species such as chryasanthemum [ 76 ], soybean [ 17 ], rice [ 69 ], Lablab purpureus [ 63 ], and Festuca arundinacea [ 77 ], high temperature stress-induced decrease in photosynthesis alleviated by SNP treatment has been reported. In the present study, the activity of Rubisco was severely affected by the exposure to high temperature stress.…”

“…Application of sodium nitroprusside (SNP; NO source) has been found to stimulate activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POD) under high temperature (45 °C) in reed plant callus and played an important role in the metabolism of H 2 O 2 [ 16 ]. While high temperature stress disturbs membrane thermo-stability and increases lipid peroxidation and electrolyte leakage in plants due to heat-induced oxidative burst [ 17 ], NO interacts with superoxide and hydroperoxyl radicals to act as a barrier and terminate their chain formation and ensure the protection of the membrane [ 18 ]. Several studies have shown that NO counteracts abiotic stress strongly by regulating sulfur (S)-assimilation [ 19 , 20 , 21 ].…”