Impact of Salicylic Acid Application on Growth, Photosynthetic Pigments and Organic Osmolytes Response in Mentha arvensis under Drought Stress

Abstract

Background and Objective: The drought stress restricts the normal growth and development of plants. Salicylic acid (SA) is considered from the essential chemical compounds used to reduce the dangerous impacts of drought stress on plants. The objective of this study was to evaluate the growth attributes, some biochemical parameters of drought-stressed peppermint plants to salicylic acid application. Materials and Methods: A pot experiment was carried out to investigate the response of the morphological parameters (plant height, root length fresh and dry biomass), photosynthetic pigments (chlorophyll a and b, carotenoids and total pigments) and some organic osmolytes (proline, total soluble sugar and total soluble nitrogen) of peppermint (Mentha arvensis L.) grain pre-soaked in SA (0.05 M) and grown under drought conditions. Results: The data obtained in this study showed that drought stress significantly caused a massive reduction in the growth parameters and photosynthetic pigments but caused a remarkable increase in the root length and the organic osmolytes. Furthermore, the application of SA neutralized the reverse impacts of drought stress on the peppermint plant. The highest values of all the measured parameters were observed with droughted and nondroughted plants treated with SA. Conclusion: In general, results showed that water stress caused negative impacts on peppermint plant growth which was mitigated by the salicylic acid pre-soaking which was accompanying with some significant modification in some physiological processes. Moreover, these findings indicate that salicylic acid can be used to enhance the drought-tolerance in peppermint plant.