Enhancing Salt Tolerance in Soybean by Exogenous Boron: Intrinsic Study of the Ascorbate-Glutathione and Glyoxalase Pathways

Abstract

Boron (B) performs physiological functions in higher plants as an essential micronutrient, but its protective role in salt stress is poorly understood. Soybean (Glycine max L.) is planted widely throughout the world, and salinity has adverse effects on its physiology. Here, the role of B (1 mM boric acid) in salt stress was studied by subjecting soybean plants to two levels of salt stress: mild (75 mM NaCl) and severe (150 mM NaCl). Exogenous B relieved oxidative stress by enhancing antioxidant defense system components, such as ascorbate (AsA) levels, AsA/dehydroascorbate ratios, glutathione (GSH) levels, the GSH and glutathione disulfide ratios, and ascorbate peroxidase, monodehydroascorbate reductase, and dehydroascorbate reductase activities. B also enhanced the methylglyoxal detoxification process by upregulation of the components of the glyoxalase system in salt-stressed plants. Overall, B supplementation enhanced antioxidant defense and glyoxalase system components to alleviate oxidative stress and MG toxicity induced by salt stress. B also improved the physiology of salt-affected soybean plants.

Salt Stress Responses and Tolerance in Soybean

“…Likely, as a micronutrient for instance boron (B) not only perform a significant role in plant physiology and development but also provide protection in soybean against salinity (up to 150 mM NaCl). Supplemental B regulates the different physiological processes and improves the cellular structural integrity in plants under salinity, as evidence it increased shoot FW, chl content, leaf RWC, and Pro accumulation with lower EL as growth enhancement, osmotic stress mitigation, and membrane stability indicator, respectively [92]. This elevated Pro indicated B-mediated osmoregulation to enhance osmotic status (Leaf RWC) under salinity in soybean.…”

“…For example, soybean seedlings grown on a pot containing Salt Stress Responses and Tolerance in Soybean DOI: http://dx.doi.org/10.5772/intechopen.102835 100 mM NaCl accumulated 38% higher H 2 O 2 and caused 25% higher lipid peroxidation compared to the seedlings grown with no NaCl [91]. Exposure to salinity (6 dS m −1 ) can also raise electrolyte leakage (EL) by 69% along with 75% and 56% increase in H 2 O 2 and malondialdehyde (MDA) contents, respectively in soybean plants [92]. A similar increment of these oxidative stress markers in a dose-dependent manner of NaCl (75 and 100 mM) was also reported by Alharby et al [5].…”

Combining Proteomics and Metabolomics to Analyze the Effects of Spaceflight on Rice Progeny

“…Studies have reported that H 2 O 2 , EL, and MDA increased in rice under salt stress. Salt stress increased EL in soybean by 69%, while H 2 O 2 and MDA contents increased by 75 and 56%, respectively ( Alharby et al, 2021 ). Similar results were observed in our study ( Figure 2 ).…”

Differential Impact of Nitric Oxide and Abscisic Acid on the Cellular and Physiological Functioning of sub1A QTL Bearing Rice Genotype under Salt Stress

“…The expression of APX encoding genes is differentially modulated by several abiotic stresses, mostly depending on duration, intensity, elicitation/induction factors, plant ages, etc. In general, plants register an upregulation in activity as a major H 2 O 2 detoxifying protein ascorbate-glutathione cycle [74]. Evidence is more pronounced where both NO-and ABA-mediated induction of APX is more common in different crop species [75].…”