Data di Pubblicazione:
2009
Abstract:
• In Strategy-I-plants, iron (Fe) deficiency induces processes leading to increased Fe
solubilization in the rhizosphere, including reduction by ferric reductases and active
proton extrusion. These processes require active respiration to function. In this work
we investigated the effect of Fe deficiency on respiratory activities of cucumber
(Cucumis sativus) roots.
• We compared oxygen consumption rate and the activities of the respiratory chain
complexes on purified mitochondria from roots grown in the presence or absence of
Fe using biochemical and molecular approaches.
• Oxygen consumption rate in apex roots was increased under Fe deficiency that
was mostly resistant to KCN and salycilichydroxamic acid (SHAM) inhibitors, indicating
other oxygen-consuming reactions could be present. Indeed, enzyme assays
revealed that lack of Fe induced a decrease in the activities of respiratory complexes
that was proportional to the number of Fe atoms in each complex. A decrease of cyt
c, Rieske and NAD9 proteins was also observed. Transmission electron microscopy
(TEM) analysis showed that mitochondria undergo structural changes under Fe
deficiency.
• Our data show that mitochondria and the electron transport chain are an important
target of Fe limitation and that mitochondria modify their function to meet higher
demands for organic acids while restricting the activity of enzymes with Fe cofactors.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
citrate synthase; Cucumis sativus; Fe deficiency; mitochondria; respiratory chain
Elenco autori:
G. Vigani; D. Maffi; G. Zocchi
Link alla scheda completa:
Link al Full Text:
Pubblicato in: