IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
RESPECTIVE EFFECTS OF HYPOXIA AND GLUMELLAE ON THE EXPRESSION OF CANDIDATE GENES INVOLVED IN ABA METABOLISM AND SIGNALLING PATHWAYS
Autor/es:
MENDIONDO, GUILLERMINA M.; LEYMARIE, JULIETTE; CORBINEAU, FRANCOISE; BENECH-ARNOLD ROBERTO L.
Lugar:
Olsztyn, Polonia
Reunión:
Conferencia; 9th ISSS CONFERENCE ON SEED BIOLOGY; 2008
Institución organizadora:
ISSS-University of Warmia and Mazury
Resumen:
Barley grains are mostly used for malting, an industrial process which requires germination. Dormancy is, then, a major constraint. This dormancy is expressed at temperatures above 15°C and is typically imposed by the covering structures which have been suggested to limit oxygen supply to the embryo. Previous data (Benech-Arnold et al., 2006) carried out at a physiological level demonstrated that hypoxia imposed either artificially or by the hulls, increases embryo sensitivity to ABA and interfere with ABA metabolism in dormant grains. The aims of the present work was to investigate at a molecular level whether the glumellae and/or hypoxia interferes with ABA metabolism and signaling pathway.  Expression of candidate genes involved in ABA synthesis (HvNCED1) and catabolism (HvABA8OH), and ABA signaling (HvABI5) was analyzed in embryos isolated from whole or de-hulled grains with different dormancy depth, incubated in air or in hypoxia (5% oxygen). Removal of the glumellae results in changes in the expression pattern of candidate genes as compared to whole grains. Hypoxia mimicked the presence of the glumellae in terms of germination response and also in terms of metabolism and sensitivity to ABA, but this was not associated with restoration of gene expression patterns. We propose that regulation of ABA sensitivity by the glumellae is not mediated only through hypoxia.