CONTRIBUTION OF GLUCONACETOBACTER DIAZOTROPHICUS PAL5 TO PHOSPHORUSNUTRITION IN STRAWBERRY PLANTS

LOVAISA, N.; DELAPORTE QUINTANA, P.; RAPISARDA, V.; GRILLO PUERTAS, M.; PEDRAZA, R.

Córdoba

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

Sociedad Argentina de Investigación Bioquímica

Intensive strawberry crop production requires the use ofphosphate fertilizers to cover deficiencies of soluble phosphorus (P) in soil. Gluconacetobacter diazotrophicus, aplant growth promoting bacteria, is able to solubilize phosphates through a non-phosphorylating extracellular oxidative pathway, which oxidizes glucose to gluconic and 2-ketogluconicacids. It has been demonstrated in our laboratorythat G. diazotrophicus PAL5 can solubilize phosphate from different sources. The aim of this work was to analyze if PAL5 contributes to P nutrition in strawberry plants. Plants were grownin sterile substrate and watered with nutrient solution in theabsence of P and with the addition of soluble or insoluble P.After 20 days, plants grown with insoluble P were inoculatedwith PAL5. Plants incubated in the absence of P presented dwarfism, low dry weight, growth index and P content; dark green leaves and poor root development. A similar deficient phenotype was observed with insoluble P. Conversely, plantsincubated with soluble P or insoluble P and PAL5 had high dryweight, growth index and P content; big, vigorous and light-green leaves and abundant roots. Beneficial effects were achieved even if bacteria were inoculated after the appearance of deficiency symptoms. In conclusion, PAL5 contributes to Pnutrition in strawberry plants by improving growth in low available P medium.