Unexpectedly, potassium content was inhibited in the order
Si < SA < GA3 by their foliar application. Salinity can
directly affect the nutrient uptake, such as Na by reducing K
uptake or by Cl by reducing NO3
uptake (Grattan and
Grieve, 1999).
Ca+2, Mg+2 and Na+ content in leaves
One of the most severe effects of salt stress is the absorption of
Na+ ions by plant roots. High levels of external Na interfere
with K acquisition by the roots, disrupt the integrity of root
membranes and alter their selectivity that must be sufficient
to meet the levels of K required for metabolic processes, for
the regulation of ion transport, and for osmotic adjustment.
Calcium is strongly a competitive with Mg+2 and the binding
sites on the root plasma membrane appear to have less affinity
for the highly hydrated Mg+2 than for Ca+2. Sodium chloride