الفهرس | Only 14 pages are availabe for public view |
Abstract Sesame (Sesamum indicum L.) is considered as one of the most important oil crops in Egypt due to its high seed oil content. This work was conducted to study the growth and physiological effects of exogenously applied phytohormones (salicylic acid (SA) and kinetin (Kin)) on drought-stressed sesame plants. The experiment was designed into 4 groups: control, drought stress, drought treated with SA (0.1, 0.5 and 1mM) and drought treated with Kin (0.05, 0.1 and 0.5 mM). It was found that drought stress adversely affected all growth parameters of sesame including plant height, fresh weight, dry weight, number of leaves and leaf area. Drought stress caused significant decrease in photosynthetic pigments, total seed oil contents, endogenous phytohormones (SA and Kin) and activities of catalase and peroxidase enzymes, while the treatments of drought stressed sesame plants with SA and Kin were found to increase all previous substances. On the other hand, drought stress caused significant increase in total soluble protein, poly peptide bands, proline, phenolic compounds and activity of L-amino acid oxidase, moreover the treatments with SA and Kin were shown to improve all previous substances in drought stressed sesame plants. The different oil extracts of the control plants, drought stressed plant and sesame plants treated with phytohormones exhibited significant antimicrobial activities against bacteria and fungi. SDS-PAGE detection of protein indicated some changes in amount and number of protein bands and also new protein bands appeared in both stressed and hormonal treated plants. Therefore, exogenous application of drought stressed sesame plants with phytohormones may induce resistance to drought stress by enhancing growth and various physiological processes which are negatively affected by drought stress. |