The effect of ethylene on plant growth and development had been known long before. This gas used as plant growth regulators. Application of this hormone in many stages of plant growth and development specified the importance of these hormones. The aim of this studies was to investigate the role of this hormone in plant which were under water shortage. Water stress caused significant differences in soil water potential. 6 days after ceasing irrigation the soil water potential dropted from 5 to 1] Bar. During this time the water contents of soil on the bases of dry weight decreased from 55 to 18 percent. Which indicate relatively high stress. To investigate how water stress function on morphology and organogenesis of plants, the internode number were counted. Internode number did not changed during stress in comparison to control plants, which showed water stress did not effect on leaf initiation but internode length were significantly reduces. Water potential highly decreased during stress and plants which were under stress up to 6 days had a water. Potential equal to 13 Bar which is relatively high stress. Total leaf area of Plants were measured. 4 days after ceasing irrigation significant decrease in total leaf area were observed. Stomata conductance significantly decrease 3 days after stress. (from If4 to 1 scm-I). 6 days after water stress treatment conductance further decrease to 0/2 scm,l. Ethylene production increased significantly when leaf water potential droped up to - 5 Bar and thereafter the amount of ethylene emanation significantly decreased. When the experiment were carried with excised leaf which were left under room temperature till leaf which were left under room temperature till leaf water potential droped to the same water potential of intact droped to the same water potential of intact plant. We observed correlation
between ethylene production and water stress. After irrigation of Plants which were stress, leaf
absiction correlation with the days which plants were under stress. In Plants which were 5 days under water stress 100 percent leaf absicion were observed. After irrigation to the lack of correlation between stress and ethylene production in more common method we try to test and compare intact flow system method with the mentioned method and the result were discussed.
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