الفهرس 
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Abstract
The effect of exogenous plant phenols (POH) extracted from spinach, amaranth, tomato and cabbage on seed germination, seedling growth, metabolic contents and activities of antioxidant enzymes of barley and bean under salinity stress was investigated. The seed germination, growth criteria, pigment contents, total soluble sugars and total proteins decreased with increasing salinity levels. Pre-treatment of barley grains or bean seeds with POH stimulated the accumulation of total soluble sugars and total protein as compared with the corresponding salinity level. Increased salinity stress and pre-treatment with POH increased the total phenols in barley and bean seedlings. Meanwhile, salinity stress induced accumulation of proline in barley and bean seedlings, and pre-treatment with POH decrease proline content as compared with those of the corresponding salinity levels. This is an indication that salt stress on plants was improved by POH pre-treatment through decreasing proline synthesis or accumulation. Pre-treatment of barley grains and bean seeds with POH improved stress resistance by the increase in catalase (CAT), peroxidase (POD) and polyphenol oxidase (PPO) activities as compared with corresponding salinity level. Barley and bean seedlings have the highest CAT and POD activities when treated with amaranth phenolic extract followed by those of treatment with tomato phenolic extract. The seedlings pre-treated with POH showed new protein bands.