The main factors that determine the processing quality of wheat flour are the types and quantities of gluten and gliadin in wheat grains and their proportions.These two are not only the main component of wheat grain storage protein,but also the two major components of wheat gluten.By affecting the processing quality of wheat flour,the quality of gluten is affected.Among them,gliadin is one of the most important components of wheat grain storage protein,accounting for 50%to 60%of the total storage protein,which determines the ductility plasticity,viscosity and plasticity of gluten and is a cause of celiac disease(celiac disease,CD).The main cause of disease.Therefore,improving and processing the quality of common wheat and reducing the incidence of celiac disease by using and screening excellent gliadin genes are of great significance for wheat genetics and breeding.Wild emmer wheat has high grain protein content and rich variation of storage protein.As an ancestor of cultivated tetraploid durum wheat and hexaploid common wheat,it is a suitable donor for genetic improvement of common wheat.The research group had previously evaluated and used wild HMW-GS and LMW-GS,and conducted molecular identification of theα/γ-gliadin genes of the wild emmer wheat and its hybrid offspring with common wheat.In this study,the wild emmer wheat(D97),common wheat cultivar Chuannong16(CN16),and their four hybrids lines BAd7-209,BAd7-210,BAd7-212 and BAd7-213(F11,2n=6x=42)were used as the experimental material.Molecular cloning of theω-gliadin gene of the A genome was performed,and the sequence comparison analysis of the published gene in Gen Bank and the cloned gene,And build a phylogenetic tree to reveal the potential value and genetic basis of the improvement of common wheatω-gliadin by using wild emmer wheat,and then provide a basis for the use value of wild emmer wheat in the improvement of ordinary wheat quality and CD prevention guide.The main results are as follows:1.A total of 139ω-gliadin gene sequences were cloned,and the encoded amino acid sequences all had the typical structure ofω-gliadin.Among them,86 gene sequences had complete coding frames,and 53 sequences were genetically silenced due to mutations,which were presumed to be pseudogenes.The occurrence of mutations was mainly concentrated in the repeat region.2.Generally,ω-gliadin is a thiol-depleted protein,and the sequence is generally relatively conservative,and contains no cysteine residues.In this study,a total of 12ω-gliadin gene sequences with one cysteine were obtained.According to the odd number of cysteine helps to participate in the formation of intermolecular disulfide bonds,it is believed that theseω-gliadin genes have the potential for a positive effect on gluten quality.3.Analysis of 53 pseudogene sequences revealed that 23 of them had early termination codons appearing in the CD peptide,which effectively inhibited the expression of celiac disease-inducing factor.Among them,there were 19 D97s,which were divided into three types.In their descendants BAd7-212 and BAd7-213,sequences consistent with the positions of early termination codons in D97 were also found.It showed that there were certain types of mutations in wild emmer wheat D97,and it might effectively introduce its high-quality genes into common wheat through distant hybridization.4.A statistical analysis of the peptides that induce celiac disease(CD)from the cloned gene sequence revealed that wild emmer wheat D97 contained less inducing CD effectors than the four sister lines and their female CN16.So,it is expected to improve the common wheatω-gliadin by using wild emmer wheat for breeding low CD toxic peptides varieties of common wheat. |