بهبود رشد گیاهچۀ توتون (.Nicotiana tabacum L) در شرایط تنش خشکی تحت تیمار متیل جاسمونات

Application of some chemical components including plant hormones such as methyl jasmonate causes resi-stance to increase in environmental stresses. In this study, the effect of metyl jasmonate in different concentrations (10, 20 and 30 uM) on the elevation of the plant resistance was investigated in drouht stress. Tobacco seedlings were studied under drought stress caused by polyethylene glycol (20%) during periods of 3, 6 and 9 days. The results revealed that the imposed stress significantly increased soluble sugar content, MDA and non-enzymatic defense factors such as ant-hocyanin and proline. In contrast, it is reduced the amount of photosynthetic pigments, carotenoids and flavonoids. On the other hand, the use of methyl jasmonate decreased malondialdehyde as a marker of lipid peroxidation and values of some detent factors such as proline, beta-carotene and MDA. Meanwhile, it increased the amount of soluble sugars and photosynthetic pigments, anthocyanins, flavonoids and flavonols. As a result of the simultaneous reduction of lipid pe-roxidation and some antioxidants, it seems that using exogenous methyl jasmonate can help the plant withstand against drought stress conditions.