INFIVE   05416
INSTITUTO DE FISIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Role of nitric oxide on lipid peroxidation in wheat plants growing under different zinc availability
Autor/es:
AGUSTINA BUET; GUILLERMO E. SANTA MARÍA; MARCELA SIMONTACCHI
Lugar:
San Pablo
Reunión:
Congreso; VII Meeting of the SFRBM South American Group; 2011
Institución organizadora:
SFRBM South American Group
Resumen:
Zinc (Zn) is an essential
nutrient for the normal growth of plants and its deficiency is widespread in
cereals. Nitric oxide (NO) is a bioactive molecule endogenously synthesized in
plants with participation in biotic and abiotic stress responses. In this work
wheat (Triticum aestivum, var. Chinese
spring) plants were grown in modified Hoagland solution with or without 2 mM Zn provided as ZnSO4. After 17 days of development plants
exhibit no changes in either total biomass or shoot/root quotient, and no
visible Zn deficiency symptoms were detected. However, in roots total Zn
measured by atomic absorption was 123±16 and 19±4 nmol/g FW, for the control
and the Zn-starved group, respectively. Shoot Zn concentrations were 134±14 and
34±5 nmol/g FW, for control and Zn deficient groups, respectively. Total Fe
content in shoots or roots was not affected by Zn-supply.
In order to study the effect
of an NO donor on the pattern of Zn accumulation, plants were exposed during 17
days to 100 µM S-nitrosoglutathione (GSNO) added to the nutritive solution. Addition
of GSNO decreased 48% and 30% the concentration of Zn in roots and shoots of
control plants, respectively, while no changes were observed in plants deprived
of Zn as a consequence of NO exposure. In turn, no differences in lipid
peroxidation, as evaluated by EPR spin trapping, between full supplemented and
Zn starved plants were observed. As expected a positive effect over lipid
peroxidation was found in control plants exposed to NO. A decrease of 40% in
lipid radicals was found in roots of plants exposed to GSNO, and a decrease of
25% was observed in shoot as compared to plants without the NO donor. This
pattern of changes in lipid peroxidation was not observed in Zn deficient plants
where GSNO did not exert a protective effect.
The lack of effect of the NO
donor, blocking the lipid peroxidation in Zn-starved plants, suggests that
exogenously added NO is being consumed by other pathways in these plants. In
plants growing in a complete medium a NO supplementation lead to alterations in
Zn concentration in the whole plant, while a lower extent of lipid peroxidation
was observed.