Physiochemical studies of sodium chloride on mungbean (Vigna radiata L. Wilczek) and its possible recovery with spermine and gibberellic acid.

Srijita Ghosh,Sanglap Mitra,Atreyee Paul

doi:10.1155/2015/858016

Abstract

The physiological and biochemical responses to increasing NaCl concentrations, along with low concentrations of gibberellic acid or spermine, either alone or in their combination, were studied in mungbean seedlings. In the test seedlings, the root-shoot elongation, biomass production, and the chlorophyll content were significantly decreased with increasing NaCl concentrations. Salt toxicity severely affected activities of different antioxidant enzymes and oxidative stress markers. Activities of antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT) increased significantly over water control. Similarly, oxidative stress markers such as proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2) contents also increased as a result of progressive increase in salt stress. Combined application of NaCl along with low concentrations of either gibberellic acid (5 µM) or spermine (50 µM) in the test seedlings showed significant alterations, that is, drastic increase in seedling elongation, increased biomass production, increased chlorophyll content, and significant lowering in all the antioxidant enzyme activities as well as oxidative stress marker contents in comparison to salt treated test seedlings, leading to better growth and metabolism. Our study shows that low concentrations of either gibberellic acid or spermine will be able to overcome the toxic effects of NaCl stress in mungbean seedlings.

Highlights

Increase in the world population and the decreasing trend of arable land has led to a marked decrease in food security with abiotic stresses, salinity being one of the major contributors in decreasing the crop productivity
On joint application of 100 mM NaCl with 5 μM GA3, the shoot length decreased by 14% over water control, while joint application of 100 mM NaCl with 50 μM Spm showed an increase of 1% over water control
25 mM and 50 mM NaCl treated test seedlings showed comparatively less damage in respect to water control and all further experiments were performed with 100 mM NaCl concentration

Summary

Introduction

Increase in the world population and the decreasing trend of arable land has led to a marked decrease in food security with abiotic stresses, salinity being one of the major contributors in decreasing the crop productivity. Salinization problems are on the increase mainly due to poor irrigation drainage or agricultural practices [2]. This drastic increase in land area being affected by salinity urges the need to develop strategies to enhance crop productivity under saline conditions. The negative effects of salinity, owing to increase in Na+ and Cl− ions (with Cl− being more dangerous), disturb the homeostasis of essential nutrients [3,4,5], leading to both hyperionic and hyperosmotic stress. Plants tend to develop multiple detoxification mechanisms to prevent ROS from damaging cellular components [10]

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Conclusion