Effect of fluorescent Pseudomonas on plant growth promotion of Aloe vera

Modern agriculture practices heavily depend on the application of chemical fertilizers and continuous application disturbs the soil quality and health. Fluorescent Pseudomonas are the well characterized group of bacteria proficient in plant growth promotion and have excellent phosphate solubilizing abilities and solubilize insoluble phosphate to plants available form via secretion of organic acids. This study focused on the phosphate solubilization ability of Pseudomonas, arouse of Aloin-A molecule, gluconic acid production, as well as biometric parameters of key medicinal plant, the Aloe vera (Aloe barbadensis). Two strains (P. putida and Pseudomonas sp.) were found very effective PSBs and solubilized 236.73 and 153.73 mg L-1 phosphate, respectively. High-performance liquid chromatography analysis (HPLC) showed the production of gluconic acid (GA). P. putida and P. sp. produced 23970 +/- 231 and 21538 +/- 129 mg L-1 GA, respectively. Inoculation of the plants with consortium of P. putida and Pseudomonas sp. enhanced the plant growth, soil available P and phosphate uptake in plants than individual inoculation. An increase in aloin-A content (18.15 and 28.71 fold) was recorded in A. barbadensis treated with a PSB consortium in a soil amended without and with TCP (tricalcium phosphate), respectively. P-uptake ultimately enhances the aloin-A synthesis and biomass of plant. Therefore, agronomic attributes of Aloe vera plants can be improved for used as a medicinal plant through application of potent Fluorescent Pseudomonas.