Effect of drought stress on proline and soluble sugar content in canola (Brassica napus L.) seedlings

Drought is one of the most important environmental stresses that adversely affect the plant growth and crop production. In this experiment، the effect of osmotic stress on proline and soluble sugars content was investigated in two canola cultivars (Brassica napus L. cv. SLM046 –drought-tolerant and cv. Hyola 308 –drought-sensitive). To establish water deficit، the 12 days old canola seedlings were placed in half strength Hoagland solution containing different levels of PEG 6000 ((0، 5%، 10% and 15% (w/v)) for 24 h. The results indicated that water stress increased proline content in shoots and roots of the studied cultivars; but in stress conditions، amount of proline in SLM046 was higher than that of in Hyola 308. On the other hand، drought increased glucose، mannose and rhamnose content in the both tissues of canola cultivars، but content of these soluble sugars in SLM046 was significantly higher than that of Hyola 308.