© 2001 Heron Publishing—Victoria, Canada
Characterization of the responses of cork oak (Quercus suber) to iron deficiency
Yolanda Gogorcena (1), Nuria Molias (1), Ajmi Larbi (1), Javier Abadía (1) and Anunciación Abadía (1, 2)
1. Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Apdo 202, 50080 Zaragoza,
Spain / 2.
Author to whom correspondence should be addressed (mabadia@eead.csic.es) / Received March 29, 2001
Summary
We studied responses of cork oak (Quercus suber L.) to iron (Fe) deficiency by comparing seedlings grown hydroponically in nutrient solution with and without Fe. Seedlings
grown without Fe developed some responses typical of the Strategy I group of Fe-efficient plants, including two- and fourfold
increases in plasma membrane ferric chelate reductase activity of root tips after 2 and 4 weeks of culture in the absence
of Fe, respectively. Moreover, seedlings grown hydroponically for 2 weeks without Fe caused marked decreases in the pH of
the nutrient solution, indicating that root plasma membrane ATPase activity was induced by Fe deficiency. Iron deficiency
also caused marked decreases in leaf chlorophyll and carotenoid concentrations, and chlorophyll concentrations were decreased
more than carotenoid concentrations. Iron deficiency resulted in an 8% decrease in the dark-adapted efficiency of photosystem
II and a 43% decrease in efficiency of photosystem II at steady-state photosynthesis. No major root morphological changes
were observed in seedlings grown without Fe, although seedlings grown in Fe-deficient nutrient solution had light-colored
roots in contrast to the dark brown color of control roots.
Keywords:
Fe deficiency, ferric chelate reductase, plant nutrition, rhizosphere acidification.
