Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/2/2002
Publication Date: 3/25/2002
Citation: HACISALIHOGLU, G., KOCHIAN, L.V. MECHANISMS OF DIFFERENTIAL TOLERANCE TO ZINC DEFICIENCY STRESS IN CROP PLANTS. AMERICAN SOCIETY OF PLANT BIOLOGISTS ANNUAL MEETING. 2002. Interpretive Summary:
Technical Abstract: Zn deficiency is a major worldwide agronomic problem causing considerable losses in crop productivity and quality. The ability of crop plants to grow and yield well under Zn limited conditions is termed zinc efficiency (ZE). Using Zn-efficient and Zn-inefficient cultivars of wheat and bean, we are undertaking several different approaches to better understand ZE mechanisms. These include: 1) characterization of root Zn absorption; 2) determination of leaf Zn compartmentation; and 3) investigations into the possible involvement of Zn-requiring antioxidative enzymes in Zn efficiency. We have found that there were no differences in root Zn uptake or Zn translocation to the shoot in efficient and inefficient cultivars. Moreover, no differences in Zn compartmentation between the leaf vacuole and cytoplasm were found in these same genotypes. We are now looking at potential differences in biochemical aspects of Zn utilization, by focusing gon the Zn requiring enzyme, Cu/Zn superoxide dismutase (SOD). Also, as it appears that the primary symptom of Zn deficiency is susceptibility to oxidative stress, we are investigating the possibility that Zn efficient genotypes maintain higher levels of Cu/Zn SOD under conditions of low Zn availability. Therefore, we will present results from experiments where leaf Cu/Zn SOD activity is quantified in Zn efficient and inefficient genotypes grown under Zn sufficient conditions, and during the early and middle stages of growth under low Zn conditions. Furthermore, we are determining the level of expression of the gene encoding Cu/Zn SOD in response to changes in plant Zn status in efficient and inefficient genotypes, and these findings will also be presented.