Potassium sulfate inducing antioxidant system to alleviate salinity stress in Mung bean (<i>Vigna radiata L</i>) cuttings: A biochemical and physiological study

Salinity stress has a detrimental effect on plant growth and yield. Assessing abnormalities in physiological and biochemical pathways is crucial for accurately estimating the situation. The present study aimed to verify the potential of potassium sulfate in alleviating oxidative stress, as measured by rooting and enzymatic antioxidant responses, in Mung bean (Vigna radiata L.) cuttings, using this experimental system. Potassium sulfate (K2SO4) was used at an optimal concentration (15 mM L-1) to alleviate sodium chloride (NaCl) toxicity 50 mM L-1 in terms of rooting response. K2SO4 was supplied in pre-, post- and simultaneous treatment with NaCl. The simultaneous treatment was found to be the best for alleviating sodium toxicity. Toxicant sodium and K2SO4 on enzymatic and non-enzymatic were studied. The results showed that toxic concentrations of NaCl caused a decline in rooting response and root dry biomass, as well as, nonenzymetic antioxidants: glutathione (GSH) (24.81%) and ascorbic acid (ASA) (52.03%), whereas malondialdehyde (MDA) leave contents, were increased (138.18%). Meanwhile, enzymetic antioxident: superoxide dismutase (SOD) catalase (CAT) and ascorbate peroxidase (APX) increased at level of 119.83%, 30.25% and 154.67%, respectively compared to d/H2O. However, indole acetic acid oxidase (IAA) increased at level of 94.99% compared to d/H2O. While treatment of mung bean cuttings with K2SO4 (2 mM/L) as a therapeutic way resulted in a contrasting trend, that caused an increase of rooting response and dry weight. The GSH and ASA increased, whereas MDA decreased at a reduction 90.17%. In addition to decrease of SOD, CAT, APX and IAA-oxidase activities at a reduction 148.09%, 12.24%, 92.39% and 126.13%, respectively. Thus, K2SO4 is a promising therapeutic management for improving the tolerance of plants under NaCl stress.