Dr. U. K. KandoliyaTrivedi Sandhyaben Kiritkumar2018-08-092018-08-092018-06http://krishikosh.egranth.ac.in/handle/1/5810063893Green house experiment was conducted to investigate the effect of exogenous application of salicylic acid (SA) under salt stress on physiological, biochemical parameters and enzymatic activities of green gram. The experimental was conducted in factorial completely randomized design with four salicylic acid concentrations (0.0, 0.5, 1.0 and 1.5 mM), four levels of irrigation to induce salinity stress (< 2 EC-tap water, 4.0 EC, 6.0 EC and 8.0 EC). The pots were irrigated with different concentrations of saline water and plants were sprayed with salicylic acid after 20 and 40 DAS (Days after Sowing), samples were withdrawn after 21, 41 and 61 DAS for the analysis. The observations were recorded for the parameters viz., relative water content, root and shoot length, leaf pH, total phenol content, true protein, free amino acid, total soluble sugar, reducing sugar chlorophyll content, carotenoids, proline, glycine betain, polyphenol oxidase, peroxidase, and catalase. The present investigation was under taken with an objective to find out the effect of exogenous application of salicylic acid as a growth regulators on physiological, biochemical and enzymatic activates. Results revealed that the foliar spray of 1.5 mM salicylic acid was more effective in all parameters. The results revealed that increasing the salt concentration in treatments resulted to increase osmolytes or solutes viz; total soluble sugar, reducing sugar, true protein, glycine betain, total phenols and proline content of seedling which sown in salinity treatments. Abstract With progressive days of germination, osmolytes or solute content in the seedling decrease in all salt stress treatments. A difference in sensitivity to salinity in green gram is reflected on physiological parameters and enzymatic activity. Salt stress that decrease physiological parameters like; relative water content, root and shoot length but leaf pH is increase in case of high salt concentration. The leaf sample that treated with salicylic acid at different concentration increased physiological parameters like relative water content, Root and shoot length, except leaf pH; salicylic acid can regulate various plant metabolic process and modulate the production of varied osmolytes like total phenol, true protein, free amino acid, total soluble sugar, reducing sugar, chlorophyll content (a, b and total), proline and glycine betain; Enzyme activity like peroxidase, but higher dose of salicylic acid decrease catalase and polyphenol oxidase enzymatic activities. Thus, effect of salicylic acid could be distinguished as evidence by increased growth, concentration of different osmolytes studied and some biomolecules as well as oxidative enzymes and emerged as the phytohormones in plant as evidenced by their significant growth promoting properties and their influence on varied physiological, biochemical and enzymatic activates as observed in present investigation.enBIOCHEMISTRYThesis