Development of Fe-deficiency responses in cucumber (Cucumis sativus L.) roots: involvement of plasma membrane H (+) -ATPase activity
Dell'Orto, M.; Santi, S.; De Nisi, P.; Cesco, S.; Varanini, Z.; Zocchi, G.; Pinton, R.
Journal of Experimental Botany 51(345): 695-701
ISSN/ISBN: 0022-0957 PMID: 10938861 DOI: 10.1093/jexbot/51.345.695
One of the mechanisms through which some strategy I plants respond to Fe-deficiency is an enhanced acidification of the rhizosphere due to proton extrusion. It was previously demonstrated that under Fe-deficiency, a strong increase in the H+-ATPase activity of plasma membrane (PM) vesicles isolated from cucumber roots occurred. This result was confirmed in the present work and supported by measurement of ATP-dependent proton pumping in inside-out plasma membrane vesicles. There was also an attempt to clarify the regulatory mechanism(s) which lead to the activation of the H+-ATPase under Fe-deficiency conditions.