Salicylic Acid– and Ascorbic Acid–Induced Salt Tolerance in Mung bean (Vigna radiata (L.) Wilczek) Accompanied by Oxidative Defense Mechanisms

Abstract

The present study aimed at investigating the physiochemical role of phytoprotectants, i.e., salicylic acid (SA) and ascorbic acid (AsA), to induce salt tolerance (0, 80 mM NaCl) in two indigenous mung bean varieties, viz. NM-92 (salt tolerant) and NM-28 (salt sensitive). The mung bean varieties were exposed to salinity stress (80 mM NaCl) after 1 week of germination and then exogenously sprayed with different levels of SA and AsA (0, 50, 100, 150 mg L −1 ) on appearance of stress symptoms. The experiment was carried out in a completely randomized design with three replications. Salinity stress significantly reduced the growth attributes and photosynthetic pigments and considerably increased electrolyte leakage (92-94%), lipoxygenase activity (113-152%), malondialdehyde (103-105%), and hydrogen peroxide (44-46%) contents. Treatment of control plants (0 mM NaCl) with SA or ASA did not significantly reduce growth attributes and photosynthetic pigments. However, exogenous SA and AsA (0, 50, 100, 150 mg L −1 ) markedly enhanced salt stress tolerance by reducing electrolyte leakage (26-34%), lipoxygenase activities (45-51%), and malondialdehyde (32-37%) and hydrogen peroxide concentration (17.2-17.5%) due to higher accumulation of stress metabolites and antioxidative enzymes. The highest increase in stress tolerance was recorded by foliar application of (100 mg L −1 SA) in NM-92. We conclude that application of 100 mg L −1 SA is an effective approach to increase salt tolerance in mung bean. Moreover, the cultivation of salt-tolerant cultivars such as NM-92 is recommended to obtain better mung bean yields in salt-affected areas.

Application of Potassium Humate and Salicylic Acid to Mitigate Salinity Stress of Common Bean

“…Figure 3 C,D show a clear trend of increasing ROS under salinity stress compared with the non-saline condition. A similar result was recorded by Nawaz et al [ 62 ], who found that salinity increased ROS levels in mungbean shoots. However, in this study, the application of SA and Kh retarded the production of H 2 O 2 under saline conditions.…”

“…The results in this study ( Figure 3 A) and those of previous studies indicate that SA application enhances the chlorophyll content of kidney bean plants [ 31 ], tomatoes [ 60 ], cucumbers [ 61 ], and mungbean [ 62 ]. These results could be due to the role of SA in increasing the relative vitality of photosynthesis and decreasing initial fluorescence [ 63 ].…”

“…Environmental stresses, especially salinity and drought, encourage the production of reactive oxygen species (ROS), including O 2 •− and H 2 O 2 , which promote the tolerance of plants to these stresses [ 62 ]. Figure 3 C,D show a clear trend of increasing ROS under salinity stress compared with the non-saline condition.…”

Productivity and antioxidant activity of mung bean sprouts (Vigna radiata L.) mediated by some elicitors

“…In the present study, SA concentrations ranged from 0.83 to 4.16 mM. The application of low SA concentrations relieves the abiotic stress sensitivity in plants corroborating the data exhibited by NAWAZ et al (2021), whereas high concentrations (usually more than 1 mM) induced high levels of oxidative stress, leading to decreased abiotic stress tolerance and reduced growth (CHANDRA et al, 2007;MACHADO-NETO;DURÃES, 2006;MIURA;TADA, 2014).…”

“…According to BRILHANTE et al (2013), exogenous application of 0.85 mM AA to cowpea seeds [Vigna unguiculata (L.) Walp] 'Epace 10' after artificial ageing attenuated the deleterious effects on membrane integrity caused by artificial ageing and favoured the physiological quality of seeds. Similarly, Vigna radiata seeds submitted to treatment with AA (NAWAZ et al, 2021;ROYCHOUDHURY et al, 2016) increased their tolerance to environmental stress caused by salinity and cadmium toxicity. ---------------------------------------------------------------------Assay 1 -1 application of 12 mL.50 sprouts -1 - --------------------------------------------------------0 -----------------------------------------------------Assay 2 -2 applications of 12 mL.50 sprouts -1 - -------------------------------------------------------0 ----------------------------------------------------Assay 3 -2 applications of 6 mL.50 sprouts -1 - ----------------------------------------------------------0 AA treatment did not produce a significant increase in total phenolic content (Figure 1).…”