Interactive effects of salinity and Nitric oxide on water relations of Zygophyllum fabago L.

Many environmental stresses can damage of plants by affecting water relations. Nitric oxide is a diffusible free radical which plays the adjustment role during stresses. In this study, the water relations of Zygophyllum fabago L. were investigated under pretreatments of nitroprusside (donor of nitric oxide) at two levels (0 and 0.2 mM ) and treatments of sodium chloride at three levels (0 , 200 and 400 mM). The results showed that high salinity significantly decreased the fresh weights of shoots and roots, relative water content, anthocyanins contents, insoluble sugars, free amino acids, and significantly increased, soluble sugars, soluble phenolic compounds and proline. Sodium nitroprusside at the concentration of 0.2 mM improved the negative impacts of salinity. Under salinity condition, osmotic potential was more negative than control and application of sodium nitroprusside enhanced it. We concluded that benefit of exogenous sodium nitroprusside on halophyte Zygophyllum fabago plants by increasing tolerance threshold to salinity through improving water relations.