Regulation of biochemical and molecular responses in cucumber roots under Fe-ieficiency

摘要

Strategy I plants respond to low iron availability by inducing a transplasma membrane Fe(Ⅲ)-reduction activity, proton extrusion and by increasing the abundance and activity of iron transporters. These mechanisms, induced at the root level, should be carefully regulated in order to adjust iron uptake to the demand of the whole plant and to prevent iron overload. Iron resupply to iron-starved plants promotes FRO2, AHAs and phosphoenolpyruvate carboxylase (PEPC) transcription as well as an increase in the enzyme activities within 24 h as effect of a co-regulated transient induction. After this phase, when the nutritional status of the whole plant is replenished according to the shoot demand, a negative co-regulation of these systems starts.