Mohammad Hadi Mirzapour; Ahmad Golchin; Amir Hosein Khoshgoftarmanesh; Mohammad Medi Tehrani
Abstract
The role of amino acids on root uptake and root-to-shoot translocation of micronutrients is of great importance to improve plant nutrition management. In this nutrient solution culture experiment, the effect of application of 100μM tryptophan, arginine and histidine on the uptake and root-to-shoot ...
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The role of amino acids on root uptake and root-to-shoot translocation of micronutrients is of great importance to improve plant nutrition management. In this nutrient solution culture experiment, the effect of application of 100μM tryptophan, arginine and histidine on the uptake and root-to-shoot translocation of zinc (Zn) and iron (Fe) in rapeseed with three Zn levels (0, 5 and 10μM as zinc sulfate) was investigated. The results showed at the 5μMZn, application of arginine and tryptophan significantly reduced the shoot dry weight compared to the amino acid-free, while at the 5μMZn, the use of histidine resulted in a significant increase in the plant shoot dry weight. The highest plant shoot Zn uptake was found at the 10μMZn plus histidine. Application of 10μMZn in the presence of arginine led to a significant increase of root Zn uptake as compared to the amino acid-free while no such effect was found in the presence of other amino acids. In the presence of amino acids, except arginine, increasing Zn concentration in the nutrient solution to 10μM resulted in lower shoot and root Fe uptake in comparison with amino acid-free. In contrast, at 10μMZn treatment, application of arginine enhanced plant shoot and root Fe uptake. The highest concentration of total amino acids in the plant shoots and roots was related to the free-Zn and free-amino acid treatment. Regardless of the type of amino acid used, the increase in Zn level up to 10μM increased the leaf activity of the catalase and ascorbate peroxidase.
Ali Asghar Ghaderi; Barat Ali Fakheri; Nafiseh Mahdi Nezhad
Abstract
In order to investigate the effects of foliar application of ascorbic acid on the growth indexes and physiological traitsof thyme under drought stress, an experiment was conducted in the split plots based on randomized complete block design with three replications at the Research Farm, Faculty of Agriculture ...
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In order to investigate the effects of foliar application of ascorbic acid on the growth indexes and physiological traitsof thyme under drought stress, an experiment was conducted in the split plots based on randomized complete block design with three replications at the Research Farm, Faculty of Agriculture University of Zabol, Iran. The main factor was drought stress and applied based on the irrigation at 75, 55 and 35% FC and the subplot was foliar application with three levels including distilled water (control), 10 mM and 20 mM ascorbic acid. Main effects of drought stress and foliar application of ascorbic acid were significant (P≤0.01) for all studied traits. The interaction of water stress and foliar application of ascorbic acid was significant only for proline. Applying severe stress compared with control was decreased the total chlorophyll, carotenoid, root and shoot dry weight (29.0, 39.9, 50.5 and 43.0%, respectively), while the leaf proline and the root length were increased (44.2 and 26.6%, respectively). The foliar application of ascorbic acid (20 mM) significantly increased the amounts of photosynthetic pigments, shoot length, root and shoot weight. Simple correlation coefficients of the traits showed a significant and positive relationship between shoot dry weight and other traits, in drought stress and 20 mM foliar application of ascorbic acid conditions. Factor analysis was identified four factors for normal and four factors for severe stress conditions that at overall were explained 98 and 95% of total variation, respectively. In general, it was concluded that photosynthetic pigments and root-related traits would be the important yield related criteria (shoot dry weight), that can be beneficial in the development of thyme with higher performance under stress conditions.