Modulation of iron responsive gene expression and enzymatic activities in response to changes of the iron nutritional status in _Cucumis sativus_ L.

Abstract

Regulation exerted by the iron status of the plant on the iron deficiency responses was investigated in cucumber roots (Cucumis sativus L.) both at the biochemical and molecular level. Absence of iron induced the expression of the CsFRO1, CsIRT1, CsHA1 and the Cspepc1 transcripts that was followed by an increase in the corresponding enzymatic activities. Supply of iron repressed gene expression, in particular those of the Fe(III)-chelate reductase and for the high affinity iron transporter and reduce the enzymatic activities. Our results confirm and extend the hypothesis of a coordinate regulation of these responses. Besides these two activities strictly correlated with iron deficiency adaptation, we considered also the H+-ATPase and the phosphoenolpyruvate carboxylase, that have been shown to be involved in this response.