DIFFERENTIAL MRNA STABILITY TO ENDOGENOUS RIBONUCLEASES OF THE CODING REGION AND 3' UNTRANSLATED REGIONS OF WHEAT (TRITICUM AESTIVUM L.) MANGANESE SUPEROXIDE DISMUTASE GENES

Authors: BAEK, KWANG-HYUN - WASHINGTON STATE UNIV; Skinner, Daniel

Submitted to: Plant Cell Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2005
Publication Date: 10/21/2005
Citation: Baek, K., Skinner, D.Z. 2005. Differential mrna stability to endogenous ribonucleases of the coding region and 3' untranslated regions of wheat (triticum aestivum l.) manganese superoxide dismutase genes. Plant Cell Reports. 25:133-139.

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 exists as several forms in a given wheat plant. In this study, we investigated how long the RNA copies, the phase of the gene that is used to generate the active enzyme, of the different forms persist in the plant cells. We found that there are significant differences in how long each form remains active in the plant cells, and that the RNA copies are broken down into specific fragments. This result suggests that various forms of MnSOD in wheat are maintained in a more active state than others, further suggesting that stress tolerance can be improved through selection of plants with specific, more stable, forms of the genes encoding the MnSOD enzyme.

Technical Abstract: The sequences of the 3' untranslated region (UTR) of the manganese superoxide dismutase (MnSOD) genes in wheat (Triticum aestivum) were found to be quite variable with different predicted thermostability. The degradation rates of the 3' UTR variants and the coding region were measured following exposure to endogenous nucleases. The degradation rates of the 3' UTR variants for 15 min were not significantly different, meaning the degradation rates of the 3' UTR variants were not directly related to the thermostability. However, the degradation rate of the coding region was significantly faster than those of the 3' UTR variants. Further investigation revealed coding region seemed to have specific sites for degradation, indicating a possibility of increasing MnSOD expression by the degradation site alteration.