ARS | Publication request: CONTRIBUTION OF SHOOT TRAITS FOR IDENTIFYING GENETIC AND PHYSIOLOGICAL FACTORS CONFERRING TOLERANCE TO ZN-DEFICIENCY STRESS IN CROP PLANTS

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 19, 2004
Publication Date: July 24, 2004
Citation: Hacisalihoglu, G., Hoekenga, O., Vallejos, E., Kochian, L.V. 2004. Contribution of shoot traits for identifying genetic and physiological factors conferring tolerance to zn-deficiency stress in crop plants. American Society of Plant Biologists Annual Meeting. p. 54.

Technical Abstract: Zn efficiency (ZE) is a genetic character of agronomic importance and its mechanisms remain elusive. Factors affecting ZE were investigated in two bean (Phaseolus vulgaris) genotypes differing in ZE and a recombinant inbred (RIL) population generated from these lines. Plants were grown in nutrient solution with low (0.1 pM) or sufficient (150 pM) Zn2+ activities. ZE was evaluated by visual scoring of leaf symptoms as well as quantitative determination of ZE. A number of parameters were evaluated, including the mode of inheritance, the role of the shoot versus root using grafting, and possible differences in Zn transport and biochemical Zn utilization in order to identify genetic and physiological factors controlling ZE in bean. Segregation analysis with an F2 population suggested that ZE was conferred by a single dominant gene. Grafting studies showed that the shoot is the site of ZE. Experiments focusing on the shoot indicated that Zn transport to and within the shoot did not play a role in ZE. However, we did find that the activities of Zn requiring enzymes such as carbonic anhydrase (CA) and Cu/ZnSOD activity were significantly higher in leaves of the Zn efficient genotypes compared with inefficient genotypes under Zn deficiency. These results collectively suggest that the shoot characteristics may be of primary importance in determining ZE in bean grown under Zn-limited conditions. Furthermore, biochemical Zn utilization may play an important role in ZE, and thus the growth and yield of bean under low Zn conditions. Further molecular genetic analysis of the RILs is underway and will be presented and discussed.