Sodium Nitroprusside Improves Performance of Barley (Hordeum Vulgare L.) Under Salt Stress

Zahid Khorshid Abbas

Department of Biology, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia.

Corresponding Author E-mail: znourabbas@ut.edu.sa

DOI : http://dx.doi.org/10.13005/bbra/2666

ABSTRACT: Soil salinity creates osmotic and ionic stress in plants that result in the suppressed water and nutrients status in plants leading to reduced growth and yield of crop plants. Although, plants activate their defense system to counter various stresses but this defense system has limitations. Therefore, it is highly desirable to manipulate the plant’s cellular system to counter the detrimental effects of stresses efficiently. Nitric oxide (NO) has been shown to act as an important signaling molecule which plays vital role in growth and development of plants and plays important role in the responses of plants to biotic and abiotic stresses. Keeping in view the vital roles of NO in plants, the present experiment was performed to study the impact of NO donor sodium nitroprusside (SNP) on growth, physiological and biochemical parameters of barley (Hordeum vulgare L. cv. Sahrawi) plants grown under 200 mM NaCl. The results showed that salt-stressed plants accumulated higher levels of proline (Pro) and glycine betaine (GB) and showed enhanced activities of antioxidant enzymes viz. superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) as compared with the control plants. But increase in osmolytes and enzyme activities could not protect the plants from NaCl-induced damage and exhibited enhanced H₂O₂ and O₂^−· content, TBARS and electrolyte leakage. All these alterations negatively affected growth (fresh and dry weight of shoot and root), and physiological and biochemical parameters [leaf chlorophyll (Chl) content, carbonic anhydrase (CA) activity and leaf relative water content (LRWC)] of stressed plants. However, NaCl-stressed plants treated with the NO donor, SNP, exhibited enhanced synthesis of Pro and GB content and activities of antioxidant enzymes that resulted in reduced H₂O₂ and O₂^−· content, TBARS and electrolyte leakage and enhanced CA activity, leaf Chl content and LRWC. Application of SNP to salt-stressed plants also improved growth characteristics. On the contrary, application of NO scavenger cPTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide] along with SNP and NaCl suppressed the effect of NO and resulted in poor defense against salinity.

KEYWORDS: Antioxidant Enzymes; Glycine Betaine; Nitric Oxide; Proline; Salinity

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