Влияние салициловой кислоты на холодоустойчивость проростков огурца

The effect of the phytohormone salicylic acid (SA) on the tolerance of cucumber seedlings ( Cucumis sativus L.) to action of the low hardening (12 oС) and damaging (4 oС) temperatures was investigated. It was found that the effect of the temperature12 °C on seedlings untreated SA contributes to their hardening, as evidenced by decrease of electrolyte leakage from cotyledons. In contrast, the temperature4 °C had damaging effect on seedlings untreated SA, resulting in an increase of electrolyte leakage. It was also found that there was a decrease of content of the end product of lipid peroxidation (POL) - malondialdehyde (MDA) in leaves and free proline at effect of the temperature12 °C, and at the action of the temperature4 °C – their accumulation. Pretreatment of SA at concentrations of 50 and 100 μM reduced electrolyte leakage from cells of cucumber seedling leaves at the temperature 12 and4 °C. Furthermore, exogenous SA reduced POL leading to a decrease of the level of MDA and also contributed to the accumulation of free proline in cotyledon leaves at the normal temperature (22 °C) and in conditions of the low hardening (12 °C) and damaging (4 °C) temperatures. The data indicate the ability of SA to activate the processes aimed to improving cold tolerance of cucumber plants.