Abstract
Morpho-physiological and biochemical responses of Arabidopsis thaliana (accession N1438) to bicarbonate-induced iron deficiency were investigated. Plants were grown in cabinet under controlled conditions, in a nutrient solution containing 5 mu M Fe, added or not with 10 mM NaHCO(3). After 30 days, bicarbonate-treated plants displayed significantly lower biomass, leaf number and leaf surface area as compared to control plants, and slight yellowing of their younger leaves was observed. Potassium (K(+)) content was not modified by bicarbonate treatment in roots, whereas it was significantly diminished in shoots. Their content in ferrous iron (Fe(2+)) and in leaf total chlorophylls was noticeably lower than in control plants. Root Fe(III)-chelate reductase and phosphoenolpyruvate carboxylase (PEPC) activities were significantly enhanced, but leaf ribulose 1.5-bisphosphate carboxylase (Rubisco) activity was decreased.