Alleviation of salt stress in lemongrass by salicylic acid

Abstract

Soil salinity is one of the key factors adversely affecting the growth, yield, and quality of crops. A pot study was conducted to find out whether exogenous application of salicylic acid could ameliorate the adverse effect of salinity in lemongrass (Cymbopogon flexuosus Steud. Wats.). Two Cymbopogon varieties, Krishna and Neema, were used in the study. Three salinity levels, viz, 50, 100, and 150 mM of NaCl, were applied to 30-day-old plants. Salicylic acid (SA) was applied as foliar spray at 10(-5) M concentration. Totally, six SA-sprays were carried out at 10-day intervals, following the first spray at 30 days after sowing. The growth parameters were progressively reduced with the increase in salinity level; however, growth inhibition was significantly reduced by the foliar application of SA. With the increase in salt stress, a gradual decrease in the activities of carbonic anhydrase and nitrate reductase was observed in both the varieties. SA-treatment not only ameliorated the adverse effects of NaCl but also showed a significant improvement in the activities of these enzymes compared with the untreated stressed-plants. The plants supplemented with NaCl exhibited a significant increase in electrolyte leakage, proline content, and phosphoenol pyruvate carboxylase activity. Content and yield of essential oil was also significantly decreased in plants that received salinity levels; however, SA overcame the unfavorable effects of salinity stress to a considerable extent. Lemongrass variety Krishna was found to be more adapted to salt stress than Neema, as indicated by the overall performance of the two varieties under salt conditions.

The impact of salicylic acid on some physiological responses of Artemisia aucheri Boiss. under in vitro drought stress

“…Moreover, many previous studies have shown that SA plays a role in many biotic and abiotic stresses (Vicente and Plasencia, 2011). This phytohormone can regulate responses to salinity (Idrees et al, 2012) and cold (Siboza et al, 2014), drought (Shen et al, 2014) and the toxicity of heavy metals (Tamás et al, 2015). Moreover, research has shown that SA levels and/or SA signaling played a positive regulatory role in plant response to polyethylene glycol (PEG)-simulated drought stress (He et al, 2014).…”

Salinity effects on pigments of Turnera diffusa (Willd.) in vitro

“…They also mentioned chlorophyll reduction could be caused by pigment destruction, instability, and syn thesis reduction by salinity stress. Idrees et al [19] observed that chlorophylls showed the greatest loss compared to carotenoids in lemongrass plants by NaCl effects, when only salinity stress was applied; however, when SA treatments with NaCl were added, negative effects decreased. The beneficial effects of SA on photosynthetic compounds were considered by stimulation on Rubisco [16].…”

“…In recent years some authors have reported the pos itive effects of SA against the negative effects of NaCl [4,5,7,16,19,[24][25][26], because SA induced directly or indirectly plant antioxidant compounds and enzymes, such as SOD, CAT, and POX, to protect the plants and prevent oxidative stress [4,26,27]. In fact, SA up regulated POX genes in plants under stress con ditions [26].…”

“…Liu et al [30] reported that salt stress (100 mM NaCl) significantly decreased POD activity in cotton seedlings, but when exogenous SA was added to plants in salinity stress (100 mM NaCl), POX activity increased. Idrees et al [19] observed other enzymes as PEP carboxylase, and they determined that when increasing NaCl concentration, the PEP carboxylase enzyme activities increased significantly with NaCl only or in combination with SA. Therefore, SA application does not modify NaCl effects [19].…”

“…Idrees et al [19] observed other enzymes as PEP carboxylase, and they determined that when increasing NaCl concentration, the PEP carboxylase enzyme activities increased significantly with NaCl only or in combination with SA. Therefore, SA application does not modify NaCl effects [19]. Simaei et al [24] reported POX activities (APOX and GPOX) vary depending on NaCl concentration.…”