Effect of time and concentration of salicylic acid foliar application on lavender polyphenol oxidase activity

As a growth regulator, salicylic acid has a variety of physiological functions in plants. Recent studies indicate that the presence of salicylic acid increases plant resistance to stress factors. The activity of salicylic acid is highly dependent on the production of reactive oxygen species. Reactive oxygen species act as messenger molecules that their dual function is strongly dependent on the concentration of them in the cell. At low concentrations Reactive oxygen species are involved in the cascading pathways of plant protective reactions, including the activation of antioxidant enzymes and protein kinase signaling pathways. However, in high concentrations they are harmful to the cell and lead to programmed cell death and apoptosis, which must be rapidly eliminated from the cell by antioxidant enzymes. Lavender with the scientific name of Lavandula officinalis belongs to the genus Lamiaceae and belongs to the genus Lavandula. Lavender is a perennial, evergreen and very fragrant plant with woody stems. Lavender essential oil contain high amount of terpenes and has sedative, carminative, antiseptic, analgesic and antimicrobial properties. Lavender is an important and high demand part of the essential oil industry. This essential oil is used in a large number of personal care products. In this study, lavender plants were sprayed in three replications at ۱۰-day intervals with different concentrations of salicylic acid (۰, ۰.۲, ۰.۵ and ۱ mM). Then, its effect on the activity of the antioxidant enzyme polyphenol oxidase was investigated. Statistical analysis of the results showed that time did not have a significant effect on enzyme activity but the effect of concentration was significant. The highest amount of enzyme activity was obtained after the first foliar application with a concentration of ۰.۲ mM. It seems that over time the plant physiology adapts to salicylic acid treatment.

کلیدواژه ها:

Plant Hormones ، Medicinal Plant ، Antioxidant enzymes