Vol. 4, Issue 12, Part F (2018)

Abstract
The present study was carried out on wheat (Triticum aestivum L.) seedling to determine the exogenous effect sodium nitroprusside (SNP) on their growth and antioxidative defence system. Nitric oxide (NO) is a very active molecule involved in many biological pathways where it has proved to be protective against oxidative stress conditions. For this investigation, PBW 343 seeds of wheat genotype were treated with varying concentrations of SNP (0, 25, 50, 100, 200, 300, 500 µM) and growth data was taken at 7 days of treatments. Exogenous application of 100 μM SNP had growth promoting effects in wheat seedlings while; higher concentration of SNP inhibited seedling growth. In comparison to control seedlings the application of 100 μM of SNP had promoting growth in wheat seedlings and increased germination percentage, shoots and root length and also increased fresh and dry weight. The results of experiment showed exogenous application of 100 μM SNP increases photosynthetic pigments content in wheat (Chl a, Chl b, total chlorophyll and carotenoid). Increasing concentration of SNP (500 μM) shows negative effect and reduced photosynthesis pigment and protein content in germinated seedlings. Supplemented with 100 μM SNP enhances activity of H₂O₂ scavenging enzymes. A reduction of hydrogen peroxide, malondialdehyde and proline contents was observed at 100 μM SNP concentration. SNP at lower concentration enhances protein content in wheat variety PBW 343. It is concluded from the present investigation that nitric oxide acts as a stimulator at low concentrations whereas at higher concentration it acts as a stress inducer.