THE RELATIONSHIP BETWEEN NITRIC OXIDE AND PLANT HORMONES IN SNP ADMINISTRATED SUNFLOWER PLANTS UNDER SALT STRESS CONDITION

Nitric oxide (NO) and sodium nitro prusside (SNP) are striking molecules and play important roles in animals and plants. SNP serves as nitric oxide donor in both group. NO can act free radical and impaires important biomolecules functions beside this it has beneficial effect recovery from salinity, drought etc. NO and SNP are beneficial and protectant molecules in cope with stressfull conditions. In plants these molecules are very important, and regulate many physiological events. In the present study, endogen abscisic acid (ABA), indole acetic acid (IAA), gibberellic acid (GA(3)) and NO levels were investigated in NaCl, SNP and plant growth regulators treated sunflower plant (Helianthus annuus L.) leaves and roots. The content of NO was higher in GA(3) + SNP treated plant leaves at 72 h. The highest IAA level was determined in IAA + SNP treated plant roots at 72 h. In NaCl + ABA treated plant leaves ABA was higher at 72 and GA(3) levels were equal or less than the control group. Our results showed that coadministration of SNP and plant growth regulators cope with salinity stress via elevated internal hormone and NO level versus salinity.