Journal of Stress Physiology &
Biochemistry, Vol. 9 No. 4
2013, pp. 39-52 ISSN 1997-0838
Original Text Copyright (cc) 2013 by Chebbi, Msilini,
Amdouni, Ouerghi
ORIGINAL ARTICLE
Data source : Google Scholar
QueryDate : 2016-12-24
Cites : 0
Differential Responses of Two Lactuca sativa Varieties to
Bicarbonate-Induced Iron Deficiency
Iron chlorosis induced by
bicarbonate is very common in calcareous soils, where bicarbonate
(HCO3-) ions are present
at high concentrations. In this
study, morpho-physiological and biochemical responses of
two Lactuca sativa
varieties (Romaine and Vista) to bicarbonate induced iron deficiency
were investigated. The culture was conducted on nutrient solution
containing 5 µM Fe and 10 mM NaHCO3, in a growth chamber
with controlled conditions. After 14 days of bicarbonate treatment, the
two varieties seedling showed a slight yellowing of young leaves
associated with a significant decline of plant biomass, leaf number and
area. Furthermore, the concentrations of the nutrient elements
(potassium, magnesium, iron and calcium) in leaves and roots of two
lettuce varieties were modified. In roots of bicarbonate treated
plants, the Fe-chelate reductase activity was increased as compared to
control in both varieties. PEPC activity was enhanced only in Vista
variety. Moreover, Fe deficiency induced a small change in the
photosynthetic parameters and chlorophyll fluorescence, especially in
Romaine variety. These changes are accompanied by decreases in ribulose
1.5-bisphosphate carboxylase/oxygenase (Rubisco) activity.
These findings indicated that Vista variety could survive
at low iron supply.
Key
words: Lactuca sativa, bicarbonate, iron deficiency,
photosynthetic activity
