| Abstract Detail
Oxidative Stress Vadvalkar, Shraddha [1]. Physiological and biochemical characterization of mannitol accumulating transgenic wheat under water deficit stress. The spring wheat cultivar Bobwhite was transformed with the mtlD gene from E.coli by the biolistic method. The gene is responsible for mannitol accumulation and has shown to result in drought and salt tolerance. Four transgenic lines (pTA2-115, pTA2-118, pTA5-104, pTA5-108), a positive control (pAHC20, containing the transgenic bar gene only) and wild type Bobwhite were grown in a green house under well-watered conditions as well as under water deficit stress. Physiological characterization was done by determining the net photosynthesis rate and conducting CO2 and light-response curves on one transgenic line (pTA2-118) and one control line (pAHC20). All lines showed significantly higher net photosynthesis rate under well-watered conditions, and there were no differences in the net photosynthesis rate among the lines. Bobwhite had the greatest aboveground biomass under well-watered conditions, but pTA2-118 and pTA 5-108 had slightly higher biomass than the wild type under stress. Biochemical characterization included activity determination of antioxidant enzymes, glutathione reductase, superoxide dismutase, catalase, and ascorbate peroxidase. The pTA2-118 line showed significant differences in the activities of all antioxidant enzymes after 30 days of water stress. There were no substantial differences in enzymatic activities between the transgenic lines and the wild type, however, which suggests that the plants were able to maintain a balance between the activities of all antioxidant enzymes even under water deficit stress. Mannitol is known to scavenge hydroxyl radicals. The possible role of mannitol in preventing lipid peroxidation when exposed to drought will be evaluated by testing for malon dialdehyde and by using a direct hydroxyl radical scavenging assay.
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1 - Oklahoma State University, Plant and Soil Sciences, 125 Brumley, Apt-11, Stillwater, OK, 74074, USA
Keywords:
drought tolerance.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P06026
Abstract ID:2479 |
