The interaction between drought stress and salicylic and ascorbic acids on some biochemical characteristics of Satureja hortensis

Abstract

Water is one of the most important environmental factors that regulate plant growth and development, and water deficit is considered the most important restricted factor for plant products, in that several chemical materials have been used to reduce the harmful effects of water deficit. Some of these compounds (for instance, ascorbic and salicylic acid) have antioxidant effects in plants. In order to study the interaction between drought stress with salicylic and ascorbic acid on some biochemical criteria of Satureja hortensis, a factorial experiment with a completely randomized design in three replications and different combination of three levels of irrigation (1/3, 2/3 and total field capacity), three levels of salicylic acid (0, 1 and 3 mM) and three levels of ascorbic acid (0, 1 and 3 mM) under green house conditions was conducted. Results, revealed under aridity, sugar content and protein content of S. hortensis, were decreased; however, proline and lipid per oxidation increased. The results concluded that when drought stress affected the plants, the protective mechanism was activated. The reduction of protein content in this condition showed that drought stress affected protein synthetic and degradation. The reduction of sugar content showed that stress affected the photosynthetic process. On the other hand, in the presence of both salicylic and ascorbic acids, the harsh influences of water deficit reduced and some growth parameters increased. It seemed that two external acids were able to enhance the tolerant ability of the plant to aridity stress. Key words: Satureja hortensis, water deficit, salicylic acid, ascorbic acid.