Phenol induced physiological stress in hydroponically grown lettuce ( Lactuca sativa L.)— Part 2

Abstract

In this study we investigated physiological parameters of stress (enzymatic and non-enzymatic) in lettuce (Lactuca sativa L.) and its hairy roots induced by water solution of phenol. Two varieties of lettuce were examined, Ljubljanska ledenka and Nansen. Plants were grown in water with phenol concentration of 200 mgL−1 during 10 days. We monitored activity of peroxidases, catalases, polyphenol oxidase and superoxide dismutase, as well as proline and chlorophyll content. We observed a decrease in peroxidases, and increase in activity of catalase, polyphenol oxidase and superoxide dismutase compared to control plants. The concentration of proline was constantly increasing in both lettuce varieties over the course of the experiment. We detected an increase in activity of all monitored enzymes, except polyphenol oxidases, in hairy roots. The hydroponic system provides a useful framework for studying the effect of different harmful substances and its elimination. In such a system, as used in this work for the study of physiological processes in antioxidant protection activated when plant was exposed to phenol, lettuce and its hairy roots can be viewed as tools for water remediation.