Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/3/2002
Publication Date: 8/3/2002
Citation: HACISALIHOGLU, G., HART, J., CAKMAK, I., KOCHIAN, L.V. MECHANISMS OF PLANT ZINC EFFICIENCY: THE CONTRIBUTION OF BIOCHEMICAL ZINC UTILIZATION. AMERICAN SOCIETY OF PLANT BIOLOGISTS ANNUAL MEETING. 2002. Interpretive Summary:
Technical Abstract: Zinc (Zn) deficiency is widespread in numerous crops and results in significant yield losses around the world. Application of Zn fertilizers is not an economically viable solution for this problem; therefore more efficient utilization in zinc efficient genotypes may be a more reasonable solution. The ability of plants to maintain high yield under Zn deficiency is defined as Zn efficiency (ZE). The mechanisms governing ZE are not well understood. In this study, Zn efficient wheat genotypes with high yield on soils with low or limiting levels of plant available Zn have been used. Chelate-buffered solution culture techniques were employed to provide a range of appropriate Zn2+ activities. In the current study, root to shoot Zn translocation, levels of soluble Zn in the leaves, subcellular Zn compartmentation in leaf cells, and biochemical utilization of Zn were investigated to determine possible ZE mechanisms. Biochemical Zn utilization was investigated by looking at the expression of genes encoding the activity of the key Zn requiring enzymes CuZn superoxide dismutase (CuZnSOD) and carbonic anhydrase (CA), as well as activities of the respective enzymes in Zn efficient and inefficient wheat lines grown under low and sufficient levels of Zn. We found that CuZnSOD and CA enzyme activities were significantly higher in Zn efficient wheat lines compared with Zn inefficient lines under Zn deficiency conditions. Furthermore, these higher activities were associated with higher levels of mRNA expression, at least for CuZnSOD. These findings suggest that biochemical utilization of Zn may play a role in wheat ZE. Current research continues with bean genotypes to study ZE mechanisms in dicots. The current status of this project and further results will be presented.