INFIVE   05416
INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Characterization of the antioxidant response in two Populus deltoides clones with different sensitivity to flooding
Autor/es:
RODRÍGUEZ MARÍA EMILIA; ACHINELLI, FABIO; BÁRTOLI CARLOS; LUQUEZ VIRGINIA M.C.
Lugar:
Vancouver
Reunión:
Simposio; IPS VI; 2014
Institución organizadora:
IUFRO
Resumen:
Flooding causes
anoxia or hypoxia in plants. When the stress episode ends, sudden oxygen
exposure of tissues that have lacked oxygen can induce the generation of active
oxygen species (AOS), causing oxidative stress damage. To prevent this, plants
have systems of enzymatic and non-enzymatic antioxidants. There is no
information on the impact of post-anoxic injury in the recovery of Populus plants after flooding, nor
whether the degree of susceptibility is related to the antioxidant content. Our
aim was to characterize the response of the antioxidant system in poplar during
flooding and post-flooding period. Two P.
deltoides clones with different response to flooding, Alton (tolerant) and
ST67 (sensitive), were grown in pots in a greenhouse. Flooding was imposed by
covering the pots with tap water up to 5 cm over the soil surface, for 28 days. Afterwards,
pots were removed from the water and left to drain for one day. Leaf and root
samples were taken on days 0 and 28 of the flooding period, and 0 and 24 hours
after the end of flooding. Ascorbic acid (AsA), glutathione (GSH), peroxidase
(PX) and ascorbate peroxidase (APX) were determined. In leaves and roots of flooded
Alton plants,
no change was observed in AsA, GSH and PX levels, and APX only had a transient
increase immediate to reoxygenation. These results could indicate that
antioxidants would be removing AOS generated during post-anoxic stress, without
its detoxification capacity being exceeded. In leaves of flooded plants of
ST67, AsA increased during recovery. In roots, AsA and GSH content were reduced,
and APX activity was enhanced, both at the end of
flooding and during recovery. The response of this clone suggests that
antioxidants would be removing AOS generated both by flooding and post-anoxic
stress. The greater antioxidant response of ST67 with respect to Alton,
indicate a higher level of stress, which is consistent with its greater growth
reduction during an episode of flooding.