Role of bacterial pyrroloquinoline quinone in phosphate solubilizing ability and in plant growth promotion on strain Serratia sp. S119

LUDUEÑA, L.; ANZUAY, M.; ANGELINI, J.; BARROS G.; LUNA, M.; MONGE, M.; FABRA, A.; TAURIÁN, T.

SYMBIOSIS

SPRINGER

Lugar: Berlin; Año: 2016

0334-5114

Aims. The aim of this study was to analyze if cofactor pyrroquinoline quinone from Serratia sp. S119 is involved in the inorganic phosphate solubilization mechanism and in its ability to promote the plant growth. Methods and Results. Site directed mutagenesis was performed to obtain a pqqE- minus mutant of strain Serratia sp. S119. The phosphate solubilization ability, gluconate and PQQ production of the mutant Serratia sp. RSLpqqE- was analyzed. Mutant RSLpqqE- showed significant decrease in P soluble and gluconic acid levels produced and undetectable levels of PQQ protein compared with wt strain. Complementation with synthetic PQQ protein restored P solubilization and gluconate production reaching the levels produced by wild-type strain. The effect of the inoculation of the mutant on peanut and maize plants was evaluated in pot assays. Plants growth parameters showed no differences among the different treatments indicating that PQQ from Serratia sp. S119 is not involved in the growth promotion of these plants. Conclusions. PQQ protein is essential for phosphate solubilization ability of Serratia sp. S119 but is not required for growth promotion of peanut and maize plants. Significance and Impact of the Study. This study demonstrates the importance of PQQ in bacterial phosphate solubilization phenotype.