2 research outputs found
Membrane permeability and micro- and macroelement accumulation in spring wheat cultivars during the short-term effect of salinity- and PEG-induced water stress
The comparative responses of ten spring wheat
cultivars to water stress were investigated. Wheat plants
were cultured under hydroponics conditions (Hoagland
nutrient) to the stage of three-leaf seedlings. Then, the
water medium was supplemented with PEG (drought) or
NaCl (salinity) to obtain a water status equal to
-
1.5 MPa.
After a 2-day treatment, the changes in the following
parameters were determined: fresh and dry weight, macro-
and microelement accumulation, membrane injury (elec-
trolyte leakage, lipid peroxidation) and fatty acid content of
the phospholipid fraction of plasmalemma (in comparison
to plants not stressed, taken as a control). Generally, the
plants were more significantly influenced by water stress
stimulated by PEG than by NaCl treatment, as compared to
the plants cultivated in the control media. The results of the
decrease in water content in leaves and electrolyte leakage
from cells corresponded well with the intensity of lipid
peroxidation (determined by malondialdehyde—MDA-
content) and were chosen for the selection of investigated
genotypes for tolerance to both stresses. The more tolerant
genotypes exhibited the opposite changes in phospholipid
fatty acid unsaturation for two applied stresses i.e. NaCl treatment caused a decrease in unsaturation whereas in
PEG-treated plants an increase in unsaturation was
observed. These changes were reversed for less tolerant
plants, i.e. NaCl treatment influenced an increase in fatty
acid unsaturation whereas in PEG-treated plants a decrease
in unsaturation was measured. The ratio of U/S (unsatu-
rated to saturated fatty acids) correlated with the total
amount of accumulated macroelements. The content of
Mg, Ca and S in leaves of plants undergoing both stress
factors (NaCl and PEG) dropped whereas the K and P
content increased in leaves of wheat seedlings cultured on
media containing NaCl only. For microelements, a
decrease in the accumulation of these nutrients was
detected in all investigated seedlings. However, a greater
reduction in the level of these elements occurred in seed-
lings grown on media with PEG in comparison to those
grown on NaCl containing media