ROOT EXUDATION AND ZINC UPTAKE BY BARLEY GENOTYPES DIFFERING IN ZN EFFICIENCY |
| |
| Authors: | MirHasan Rasouli-Sadaghiani Behzad Sadeghzadeh Ebrahim Sepehr Zed Rengel |
| |
| Institution: | 1. Department of Soil Science, Faculty of Agriculture , Urmia University , Urmia, Iran;2. Soil Science and Plant Nutrition , University of Western Australia , Crawley, Australia;3. Soil Science and Plant Nutrition , University of Western Australia , Crawley, Australia;4. Dryland Agricultural Research Institute (DARI) , Margheh, Iran;5. Department of Soil Science, Faculty of Agriculture , Urmia University , Urmia, Iran;6. Soil Science and Plant Nutrition , University of Western Australia , Crawley, Australia |
| |
| Abstract: | Two barley cultivars (‘Sahara’ = Zn-efficient and ‘Clipper’ = Zn-inefficient) were grown at different soil Zn fertilization (0, 0.2, 0.8, 1.6 and 3.2 mg Zn kg?1 soil). Root exudates were collected 16 and 28 days after sowing. At Zn = 0, shoot dry matter was decreased in both genotypes, but more distinctly in ‘Clipper’. At 0.2 mg Zn kg?1, the ‘Sahara’ shoot concentrations of Zn was 130% higher and shoot Zn content 44% greater compared with ‘Clipper’. Low-molecular-weight organic acid anions (=carboxylates) (malate, maleate, fumarate and cis-aconitate) and amino acids (alanine, valine, proline, aspartic acid and glutamic acid) were detected in root exudates, with the highest concentration at Zn = 0.2 mg kg?1 soil. Higher concentrations of organic acid anions as well as amino acids were noted in the rhizosphere of ‘Sahara’ than ‘Clipper’. The genotypic differences in Zn acquisition from soil may be linked to differential carboxylate and amino acid composition of root exudates. |
| |
| Keywords: | amino acids genotypic differences organic acids rhizosphere zinc availability efficiency |
|
|
