Effects of salicylic acid on growth and proline of cucumber seedlings

The effects of salicylic acid (SA) on growth and proline were investigated in cucumber seedlings. Exogenous application of SA(100 uM - 1mM) led to a noticeable decrease in root and shoot growth, and dry weights of seedlings. Anatomical observation on leaf anatomy of cucumber revealed that the thickness of all leaf tissue components decreased in SA-treated plants. The effect was most promounced on the width of the adaxial epidermis. In the separate and simultaneous effects of SA and water deficit induced by PEG on growth and proline accumulation, the water deficit treatments had greater effects on growth traits and proline content than SA. Combinations of SA and PEG decreased dry matter and root length, and resulted in higher proline in both shoots and roots than SA stress alone. Shoots had higher proline than roots.