Morphological and physiological changes in two Triticium aestivum cultivars differing in water stress tolerance
2015
Abdalla, M. M.
Regular depriving two Triticum aestivum cultivars of water for either 1, 3 or 6 days then irrigating them throughout 32 days , progressively declined the shoot growth including (linear growth , number and area of leaves, fresh and dry weights of shoots) , the percentage of relative water content (%RWC) , photosynthetic and transpiration rates, the contents of both chlorophyll a+b and total chlorophyll and each of auxins , gibberellins , and cytokinins of leaves. It also drastically decreased the values of polysaccharides, total sugars (TS), phosphorus , potassium , magnesium ,calcium and the activity of catalase in the shoots and roots of both varieties. Reversibly, water stress stimulated the linear growth and number of adventitious roots, and their fresh and dry weights. Additionally, it raised the contents of absicisic acid (ABA), carotenoids, direct reducing sugars (DRS), proline, sucrose, sodium , iron and the activities of both hydrolytic (invertase, α and β-amylase) and oxidative enzymes (peroxidase, polyphenol oxidase and IAA- oxidase ) in the shoots and roots of both varieties above those of the untreated controls. However, these changes were more pronounced in the sensitive varieties and with the period and severity of drought.
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