Document Type : Research Paper
Department of Horticulture, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Salicylic acid (SA) is a common, plant-produced signal molecule that is
responsible for inducing tolerance to a number of biotic and abiotic stresses. An
experiment was therefore conducted to test whether the application of SA at
various concentrations (0, 0.25, 0.50 or 1.0 mM) through a seed-soaking method
would protect cucumber (Cucumis sativus L.) seedlings subjected to salt stress.
After soaking, seeds were sown in plastic trays filled with washed fine sand. The
trays were then placed in the greenhouse and watered with different NaCl solutions
(0, 50, 100 and 150 mM), for a period of 4 weeks. SA improved the majority of
physiological (relative leaf chlorophyll content, leaf relative water content and
chlorophyll fluorescence ratio) and morphological parameters (total emergence,
mean emergence time, shoot and root dry weights) of cucumber seedlings
subjected to salt stress. SA improved the injuries caused by salt stress by promoting
K+ accumulation and preventing increases in leaf electrolyte leakage and Na+
contents of leaves and roots. The best protection appeared to be obtained from SA
applied by seed-soaking method at 1.00 mM.