ESTIMATION OF AUXINS AND GIBBERELLINS SECRETED IN VITRO BY PHOSPHATE SOLUBILIZING BACILLUS MEGATERIUM

Phosphate-solubilizing bacteria secrete the phytohormone essential for plant growth and crop productivity. In the present study, rhizospheric soil samples were collected to screen out the Phosphatesolubilizing bacteria having plant growth-promoting activities. A total of 12 phosphate-solubilizing bacteria were isolated, and those having a solubilization zone of 3-12 mm were chosen for Auxin and Gibberellin production studies. Auxin and Gibberellin production were confirmed qualitatively and quantitatively using the colorimetric method. All PSB isolates (PSB1 to PSB12) showed all plant growth promoting attributes, result positive. From all the isolates, PSB1 showed Maximum PGP production compared to the others, such as indole acetic acid (130 µg/ml) and gibberellic acid (720 µg/ml) strain PSB 1 was more effective for plant growth and sustainable agriculture. The ability of PSB to promote plant development was examined using a seed germination and pot assay study. Bacterial isolates with high potential of auxin and gibberellin production were found to show the enhanced 100% seed germination and plant growth promotion for wheat seeds, as compared with the untreated seed control. It enhanced both root and shoot length. After biochemical identification, it was observed that PSB 1 was Bacillus megaterium. Genus Bacillus, due to its enhanced hormone-producing abilities, stands out as a promising candidate for sustainable agricultural applications aimed at reducing chemical inputs, improving crop yield, and promoting environmental sustainability