Submitted to: Plant Cell Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2005
Publication Date: 11/25/2005
Citation: Baek, K., Skinner, D.Z. 2005. Differential expression of manganese superoxide dismutase sequence variants in near isogenic lines of wheat during cold acclimation. Plant Cell Reports. 25:223-230.
Interpretive Summary: The antioxidant enzymes are of critical importance in the response of plants to various stresses. One form of antioxidant, manganese superoxide dismutase (MnSOD), has been shown to be essential for plant survival. We found that MnSOD responds quickly to the onset of cold temperature, and that MnSOD exists as several forms in a given wheat plant. In this study, we investigated specifically how the different forms of the genes encoding the MnSOD enzyme respond to cold temperature. We found that specific forms of the genes respond at different rates, and for different durations, to the onset of cold. These results suggest specific forms of MnSOD in wheat are more cold-responsive than others, suggesting tolerance of cold temperature may be improved through the development of wheat plants with specific combinations of genes encoding MnSOD.
Technical Abstract: Numerous sequence variants of wheat (Triticum aestivum L.) manganese superoxide dismutase (MnSOD) gene have been found. Quantitative real- time PCR was used to measure the expression levels of three MnSOD genes distinguished by a variable amino acid, and three genes distinguished by sequence variation in the 3' untranslated region (3' UTR), in wheat plants grown at 20ºC and cold-acclimated for one to four weeks at 2ºC. The amino acid variants did not differ significantly in expression levels, however, differential expression of genes differing in the 3' UTR was observed. Diploid wheat-related species also carried sequence variants of MnSOD, with differing levels of expression, indicating diversification of the MnSOD gene family occurred prior to the polyploidization events of hexaploid wheat.