Abstract

Effect of a short-term (15, 30, 60, and 120 min) root treatment with melatonin (0.1 pM and 1.0 µM) on physiological parameters of the leaf was studied in 21-day-old cucumber (Cucumis sativus L.) plants, early cv. Izyashchnyi, grown on Murashige-Skoog nutrient medium. Experimental data concerning kinetics of melatonin influence have shown that the duration of the aftereffect necessary for activation of photosynthesis, transpiration, and stomatal conductance of cucumber leaves decreased when the concentration of the exogenous melatonin used for root treatment rose. A similar pattern was observed in respect to intensification of lipids’ peroxidation, content of proline, and activation of guaiacol-dependent peroxidase (ЕС 1.11.1.7). Under the effect of melatonin, antiradical activity in the leaf decreased in 120 min, which was preceded by a reduction in the content of total flavonoids. Regulation in activity of antioxidant enzymes superoxide dismutase (ЕС 1.15.1.1) and catalase (ЕС 1.11.1.6) was more intricate. Possible mechanisms of the influence of melatonin on parameters of photosynthesis in cucumber leaves are discussed.

中文翻译：

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褪黑素短期处理对黄瓜叶片光合作用的影响

摘要

在21日龄黄瓜（Cucumis sativus）中研究了褪黑素（0.1 pM和1.0 µM）短期（15、30、60和120分钟）根处理对叶片生理参数的影响L.）植物，早期简历。Izyashchnyi，生长在Murashige-Skoog营养培养基上。关于褪黑激素影响动力学的实验数据表明，当用于根部处理的外源褪黑激素浓度升高时，激活黄瓜叶片的光合作用，蒸腾作用和气孔导度所必需的后效应的持续时间会减少。在脂质过氧化的增强，脯氨酸的含量以及愈创木酚依赖性过氧化物酶的活化方面观察到类似的模式（1.11.1.7）。在褪黑激素的作用下，叶片中的抗自由基活性在120分钟内下降，然后总黄酮含量降低。抗氧化酶超氧化物歧化酶（ЕС1.15.1.1）和过氧化氢酶（ЕС1.11.1.6）的活性调控更为复杂。