IBAM   22618
INSTITUTO DE BIOLOGIA AGRICOLA DE MENDOZA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Bacillus licheniformis, Pseudomonas fluorescens and Terribacillus saccharophilus isolated from grape roots produce GA1 in chemically-defined cultures
Autor/es:
SALOMÓN MV; BOTTINI R; PICCOLI P
Lugar:
Tarragona, España
Reunión:
Congreso; 20th IPGSA Conference on plants growth substances.; 2010
Institución organizadora:
IPGSA
Resumen:
Although grape is the fruit of major economic importance worldwide, few
microbiological studies of soil and roots have been reported for the species. Plant
growth promoter bacteria are inoculated into many crop species with the aim to increase
yield. One mechanism by which bacteria can produce such a benefit for the plant is the
production of phytohormones, namely IAA, gibberellins and ABA. We isolated and
characterized by 16S rRNA gene sequences analysis several bacteria from soil adjacent
and roots of Vitis vinifera L. cv. Malbec, among them Bacillus licheniformes,
Pseudomonas fluorescens and Terribacillus saccharophilus. The aim of this study was to
evaluate the ability of these three bacteria to produce phytohormones in chemically
defined media. The cultures were grown 5 days in NFB modified medium, controlling
OD540 (total biomass) and CFU ml-1 (cells alive). Although bacterial mass grew along
the time, the number of cells alive was reduced towards the end in all the cultures. At
this time only GA1 was characterized by GC-EIMS, but not IAA, ABA or GA3 as it has
been reported for the genus Azospirillum and other rhizobacteria under similar
conditions and by MS method. By using isotopically-labeled GA1 the amounts
produced were calculated in 0.86, 0.61 and 0.96 ng.mL-1 of culture for B.
licheniformis, P. fluorescens and T. saccharophilus, respectively. This is the first report
of phytohormonal production by indigenous bacteria isolated from grape roots and
adjacent soil