IBAM   22618
INSTITUTO DE BIOLOGIA AGRICOLA DE MENDOZA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Bacteria isolated from roots and rhizosphere of Vitis vinifera retarded water losses via production of abscisic acid and induced synthesis of defense-related terpenes in in vitro cultured grapevine
Autor/es:
SALOMON M.V.; BOTTINI R.; COHEN A.; MORENO D.; GIL M.; PICCOLI P.
Lugar:
Shanghai
Reunión:
Conferencia; 21th IPGSA International conference on plants growth substances; 2013
Resumen:
Eleven
bacterial strains were isolated at different soil depths from roots
and rizhosphere of grapevines from a commercial vineyard. By 16S rRNA
gene sequencing 9 strains were identified, among them Bacillus licheniformis RtM10 and Pseudomonas fluorescens
RtM10 were selected according to their characteristics as plant growth
promoting rizhobacteria (PGPR). Both produced abscisic acid (ABA), indol-3-acetic acid (IAA) and the gibberellins A1 and A3 in chemically-defined medium. They also colonized roots of in vitro-grown Vitis vinifera cv. Malbec plants. As result of bacterization ABA levels in 45 days-old in vitro plants were increased 76-fold by B. licheniformis and 40-fold by P. fluorescens as compared to controls. Both bacteria diminished plants water loss rate in correlation with increments of ABA. Twenty and 30
days post bacterization the plants incremented terpenes. The
monoterpenes α-pinene, terpinolene, 4-carene, limonene, eucalyptol and
lilac aldehyde A, and the sesquiterpenes α-bergamotene, α-farnesene,
nerolidol and farnesol were assessed by gas chromatography-electron
impact mass spectrometry analysis. α-pinene and nerolidol were the most abundant (µg per g of tissue in plants bacterized with P. fluorescens).
Only α-pinene, eucalyptol and farnesol were identified at low
concentration in non-bacterized plants treated with ABA, while no
terpenes were detected in controls. The results obtained along with
others from literature suggest that B. licheniformis and P. fluorescens
act as stress alleviators by inducing ABA synthesis so diminishing
water losses. These bacteria also elicit synthesis of compounds of
plant defense via an ABA independent mechanism.