IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Differential expression of abscisic acid metabolism and signalling genes induced by seed-covering structures or hypoxia in barley (Hordeum vulgare L.) grains.
Autor/es:
MENDIONDO G.M., LEYMARIE J., FARRANT J., CORBINEAU F. AND BENECH-ARNOLD R.L.
Revista:
SEED SCIENCE RESEARCH
Editorial:
CAMBRIDGE UNIV PRESS
Referencias:
Año: 2009
ISSN:
0960-2585
Resumen:
Dormant barley grains cannot germinate at 308C and
this inability to germinate is imposed mostly by the
glumellae which have been suggested to limit oxygen
supply to the embryo. Hypoxia imposed either
artificially or by the glumellae to embryos from dormant
grains, increases embryo sensitivity to abscisic
acid (ABA) and promotes the accumulation of ABA
during the first hours after imbibition. Expression
of candidate genes involved in ABA synthesis
(HvNCED), catabolism (HvABA8OH1) and signalling
(HvABI5, HvVP1 and HvPKABA) was analysed in
embryos isolated from dormant whole or de-hulled
grains incubated in air or in hypoxia (5% oxygen). The
presence of the glumellae enhanced the expression of
genes involved in ABA metabolism and signalling with
respect to that observed in de-hulled grains incubated
in air. These results suggest that at least part of the
observed physiological responses to the presence of
the glumellae are regulated at the level of gene
expression. However, hypoxia imposed on dormant
de-hulled grains did not mimic the presence of the
glumellae in terms of expression of candidate genes.
Hypoxia mimics the presence of the glumellae in terms
of dormancy maintenance and ABA accumulation and
sensitivity, but its effects appear to operate through
different mechanisms.8C and
this inability to germinate is imposed mostly by the
glumellae which have been suggested to limit oxygen
supply to the embryo. Hypoxia imposed either
artificially or by the glumellae to embryos from dormant
grains, increases embryo sensitivity to abscisic
acid (ABA) and promotes the accumulation of ABA
during the first hours after imbibition. Expression
of candidate genes involved in ABA synthesis
(HvNCED), catabolism (HvABA8OH1) and signalling
(HvABI5, HvVP1 and HvPKABA) was analysed in
embryos isolated from dormant whole or de-hulled
grains incubated in air or in hypoxia (5% oxygen). The
presence of the glumellae enhanced the expression of
genes involved in ABA metabolism and signalling with
respect to that observed in de-hulled grains incubated
in air. These results suggest that at least part of the
observed physiological responses to the presence of
the glumellae are regulated at the level of gene
expression. However, hypoxia imposed on dormant
de-hulled grains did not mimic the presence of the
glumellae in terms of expression of candidate genes.
Hypoxia mimics the presence of the glumellae in terms
of dormancy maintenance and ABA accumulation and
sensitivity, but its effects appear to operate through
different mechanisms.HvNCED), catabolism (HvABA8OH1) and signalling
(HvABI5, HvVP1 and HvPKABA) was analysed in
embryos isolated from dormant whole or de-hulled
grains incubated in air or in hypoxia (5% oxygen). The
presence of the glumellae enhanced the expression of
genes involved in ABA metabolism and signalling with
respect to that observed in de-hulled grains incubated
in air. These results suggest that at least part of the
observed physiological responses to the presence of
the glumellae are regulated at the level of gene
expression. However, hypoxia imposed on dormant
de-hulled grains did not mimic the presence of the
glumellae in terms of expression of candidate genes.
Hypoxia mimics the presence of the glumellae in terms
of dormancy maintenance and ABA accumulation and
sensitivity, but its effects appear to operate through
different mechanisms.HvABI5, HvVP1 and HvPKABA) was analysed in
embryos isolated from dormant whole or de-hulled
grains incubated in air or in hypoxia (5% oxygen). The
presence of the glumellae enhanced the expression of
genes involved in ABA metabolism and signalling with
respect to that observed in de-hulled grains incubated
in air. These results suggest that at least part of the
observed physiological responses to the presence of
the glumellae are regulated at the level of gene
expression. However, hypoxia imposed on dormant
de-hulled grains did not mimic the presence of the
glumellae in terms of expression of candidate genes.
Hypoxia mimics the presence of the glumellae in terms
of dormancy maintenance and ABA accumulation and
sensitivity, but its effects appear to operate through
different mechanisms.