Pseudomonas protegens CHA0 does not increase phosphorus uptake from 33P labeled synthetic hydroxyapatite by wheat grown on calcareous soil

Publication date: Available online 22 January 2019Source: Soil Biology and BiochemistryAuthor(s): G. Meyer, M. Maurhofer, E. Frossard, H.A. Gamper, P. Mäder, É. Mészáros, L. Schönholzer-Mauclaire, S. Symanczik, A. ObersonAbstractSoil microorganisms exuding organic acids have the potential to solubilize inorganic phosphorus (P), which could improve the P availability to plants growing on calcareous soil. The gluconic acid exuding bacteria Pseudomonas protegens CHA0 can solubilize P under glucose rich in vitro conditions, but evidence on the effectiveness in soil is lacking. This discrepancy in P solubilization between in vitro and in vivo is common for many P solubilizing bacteria. Possible causes for this discrepancy are rarely explored in soil using mechanism oriented approaches. Proposed reasons for limitation of bacterial P solubilization in soil are low persistence of the inoculant or low glucose availability in the plant rhizosphere. To test these two hypotheses we investigated the solubilization of 33P labeled synthetic hydroxyapatite (Ca33P) by the gluconic acid producing P. protegens CHA0 wild type and the mutant strain CHA1198 lacking the capacity to produce this acid, in a plant growth experiment with wheat (Triticum aestivum) and an incubation experiment. Neither in the plant growth- nor in the incubation experiment solubilization of Ca33P by strain CHA0 was detected, in spite the inoculated strain persisted in the rhizoplane of wheat and in the sterilized soi...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research