Molecular Cloning And Characterization Of An Up-regulated UDP-glucosyltransferase Gene Induced By DON From Triticum Aestivum L.cv. Wangshuibai

Wheat Fusarium head blight (FHB) caused by Fusarium graminearum, also called scab, is a destructive fungus disease of small grain cereals and maize. Scab can not only causes yield loss, more seriously is that it can also deteriorate seed quality by contaminating the infected grains with trichothecenes toxins, which are harmful to both human and animal health. Deoxynivalenol (DON) is one of the most important toxin members. It was proposed that DON acted first as a virulence factor during fungal pathogenesis and then accumulated in grain to levels posing a threat to human and animal health. To date, among the five types of FHB resistance, Type I (resistance to the initial infection) and Type II (resistance to the spread of infection) have been intensively studied. Recently, with the increasing attentions on food safety, more and more studies on TypeⅢ(resitance for toxin accumulation) were initiated. However, very few research of TypeⅢresitance were reported. Therefore, it is of great significance to identify the DON resistance-related genes and characterize the underlying molecular mechanism of DON resistance of wheat.In the present research, by expression analysis of DON-induced samples using GeneChip(?) Wheat Genome Array(http://www.affymetrix.com/products/arrays/specific /wheat.affx), a DON-resistance related gene TaUGT3 (GenBank accession FJ236328) were cloned and characterized from a scab resistant wheat(Triticum aestivum L.) variety Wangshuibai. The full-length cDNA of TaUGT3 was 1,755 bp and contained a putative open reading frame (ORF) with 496 amino acids encoding a UDP-glucosyltransferase (UGT). TaUGT3 showed high similarity in amino acid level with DOGT1 gene in Arabidopsis, which has been confirmed its function of detoxification of DON. TaUGT3 was located on the group 3 chromosomes of wheat using nullitetrasomic lines and deletion lines of ChineseSpring. Co-transformation of TaUGT3 with GFP genes to onion epidermic cells using transient transformation technique by microprojectile bombardment indicated the subcellular location of the protein encoded by TaUGT3 was in the plasma membrane and nuclear. Transformation and overexpression of the TaUGT3 gene in Arabidopsis could enhance tolerance against DON.