Effects of Iso-osmotic Concentrations of NaCl and Mannitol on some Metabolic Activity in Calluses of Two Salicornia species

Abstract

The comparative effects of salinity and drought on activity of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and polyphenol oxidase (PPO) and contents of protein, proline, hydrogen peroxide, malondialdehyde (MDA), and carotenoids were studied in calluses of Salicornia persica and Salicornia europaea. Calluses were cultured on Murashige and Skoog medium (MS medium) containing iso-osmotic concentrations of NaCl (100, 300, and 600 mM) and mannitol (200, 500, and 1000 mM). Proline content increased in calluses of both species under NaCl-and mannitol-induced stresses. Under both stresses, S. persica accumulated higher amounts of protein as compared to S. europaea. Under both stresses, protein content in S. persica decreased in comparison to control. Antioxidant enzyme activities showed different trends in the two Salicornia species under salt and drought stresses but were higher in S. europaea than in S. persica. Changes of hydrogen peroxide and MDA contents of calluses subjected to salt stress followed a pattern different from that observed under drought stress. MDA content showed similar changes to hydrogen peroxide content. Carotenoid content decreased in both species under both stresses. Overall, at the cellular level, S. europaea calluses were more tolerant to both NaCl-and mannitol-induced stresses than calluses of S. persica.

Sugar alcohols-induced oxidative metabolism in cotton callus culture

“…Other information is same as Table 1. concentrations of both osmotica caused obvious declines in the relative callus growth rates. These findings are in consistent with those of Torabi and Niknam (2011), who found no visible phytotoxic symptoms and growth retardation in the calli of Salicornia persica and Salicornia europaea grown on 1 M mannitol. However, we also observed some deviations from the normal trend.…”

“…There can be several reasons regarding this increased synthesis of proteins. For example; (1) under stressful conditions, plants can synthesize new proteins that may provide a storage form of nitrogen which is reutilized when stress is over (Torabi and Niknam, 2011) such was also in our experiment. Based on the fact that when the cotton callus culture was transferred to fresh non-stressed MS after stress period, it profusely grew (data not shown), (2) these osmotic stress causing agents are also used as carbon sources in the MS media, which may help in the increased synthesis of proteins, and (3) Coker 312 being a salt tolerant line (Gossett et al, 1996) and hence can resist osmotic stress also.…”

“…The balance between the activity of H 2 O 2 -producing enzymes and that of H 2 O 2 -scavenging plays an important role in providing a plant defense mechanism against oxidative damage (Torabi and Niknam, 2011). In our experiment, different concentrations of sugar alcohols induced significant changes in the CAT activity in case of osmolytes.…”

“…Both have a common osmotic effect (Torabi and Niknam, 2011) that induces the plants to decrease their internal water potential to avoid desiccation. The osmotic stress effects in plant cell and tissue culture can be investigated by using either ionic and penetrating (NaCl and KCl), non-ionic and penetrating (mannitol and sorbitol) or non-ionic and nonpenetrating (polyethylene glycol [PEG]) stress agents (Gangopadhyay et al, 1997).…”

Oxidative Stress Studies in Plant Tissue Culture

“…In another study, Lokhande et al (2010) observed that glycinebetain, proline and soluble sugar contents enhansed in Sesuvium portulacastrum callus under NaCl treatment. Also, in Salicarnia persica and S. europaea callus culture the increasing amounts of proline were observed under Mannitol and NaCl induced stresses (Torabi and Niknam, 2011). Cui et al, (2010) reported that proline and glucose contends were increased under sucrose-induced osmotic stress in Hypericum perfortum root suspension cultures.…”