CONTRIBUTION OF Gluconacetobacter diazotrophicus PAL5 TO PHOSPHORUS NUTRITION IN STRAWBERRY PLANTS

DELAPORTE-QUINTANA, PAOLA; GRILLO PUERTAS, MARIANA; LOVAISA, NADIA; RAPISARDA, VIVIANA ANDREA; PEDRAZA, RAÚL O

Córdoba

Congreso; 52th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016

SAIB

Intensive strawberry crop production requires the use ofphosphate fertilizers to cover deficiencies of solublephosphorus (P) in soil.Gluconacetobacter diazotrophicus, aplant growth promoting bacteria, is able to solubilizephosphates through a nonphosphorylatingextracellularoxidativepathway, which oxidizes glucose to gluconic and 2-ketogluconicacids. It has been demonstratedin our laboratorythat G. diazotrophicus PAL5 can solubilize phosphate fromdifferent sources. The aim of this work was to analyze ifPAL5contributes to P nutrition in strawberry plants. Plants were grownin sterile substrate and watered with nutrient solution intheabsence of P and with the addition of soluble or insoluble P.After 20 days, plants grown with insoluble P were inoculatedwithPAL5. Plants incubated in the absence of P presenteddwarfism, low dry weight, growth index and P content; dark green leaves andpoor root development. A similar deficientphenotype was observed with insoluble P. Conversely, plantsincubated with soluble P orinsoluble P and PAL5 had high dryweight, growth index and P content; big, vigorous and light-greenleaves and abundant roots.Beneficial effects were achieved even if bacteria were inoculated after the appearanceof deficiency symptoms. In conclusion, PAL5contributes to Pnutrition in strawberry plants by improving growth in lowavailable P medium.