Al-sensitive Barley Research Articles

Response of Calmodulin-Dependent and Calmodulin-Independent NAD Kinase to Aluminium in Root Tips from Various Cultivated Plants

The activity of NAD kinase (E.C. 2.7.1.23.) was studied in root apical meristems of various crops as well as aneuploid lines of Chinese Spring wheat cultivar growing for 4d in nutrient solution with or without alluminium. The level of aluminium tolerance in cereals (rye, wheat, barley and oat) corresponds to the level of total NAD kinase activity. In the most tolerant oat this activity is five times higher than in Al sensitive barley. Al stress causes a three-fold increase of the total NAD kinase activity in oat and two-fold in other cereals. Under these conditions calmodulin-dependent activity increases in sensitive genotypes, while it decreases in Al tolerant ones. In the two legume cultivars studied (lupine and pea) the response of total activity is exactly the reverse of that in cereals; however, the calmodulin-dependent activity follows the same course of reaction as in cereals. In Chinese Spring wheat cultivar the factors responsible for extinguishing the increase of calmodulindependent NAD kinase activity are located on the long arms of chromosomes 4D and 2D, whereas the genes located on the short arm of chromosome 5A control other mechanisms of Al tolerance.

The effect of surface applied soil amendments on barley root growth in an acid subsoil

Abstract The root growth of an Al sensitive barley (Hordeum vulgare L.) was used to evaluate the influence of surface applied amendments on the properties of an acid subsoil. Soil columns were packed with 10 cm of A horizon over 45 cm of an acidic Bt horizon from a Gilpin silt loam. Prior to planting of the barley the columns received surface treatments of dolomitic lime (8.4 Mg.ha‐1), hog manure (44.8 Mg.ha‐1) with and without lime, cow manure (44.8 Mg.ha‐1) with and without lime, gypsum (14.6 Mg.ha‐1), and EDTA (5.1 Mg.ha‐1) with lime. The columns were leached twice weekly over a 6 week period with 5 cm additions of water. Lime alone did not significantly increase subsoil pH or reduce exchangeable Al at depths below 15 cm. The EDTA plus lime treatment caused significant increases in soil pH and reductions in exchangeable Al throughout the column. Gypsum treatments also reduced exchangeable Al but neither gypsum nor EDTA plus lime treatments resulted in Improved barley root growth or rooting depth in the...