Effect Of The High Molecular Weight Glutenin Subunit Dy10-m328SF On Wheat Processing Quality

Wheat processing quality is mainly determined by the composition and content of wheat gluten.Gluten is composed of gliadin and glutenin,and glutenin is divided into high-molecular-weight glutenin(HMW-GS)and low-molecular-weight glutenin(LMW-GS).Even though HMW-GS only accounts for 10%of the wheat storage protein,they act as "network backbone" in the gluten and greatly affect the structure and property of gluten,which are among the most important determinants in the process of bread-making.We characterized a HMW-GS mutant(Dy10-m328SF)with faster mobility than Dy10(wild type)in SDS-PAGE.The coding region of Dy10 and Dy10-m328SF were sequenced and aligned.In addition,seeds of PZ1 and PZ1-Dy10-m328SF were grown and harvested at seven experimental stations(i.e.Wenjiang,Chongzhou,Rongxian,Xichang,Hanyuan,Youxian and Jingyan),and used to elevate the effect of Dy10-m328SF on wheat processing quality.The main results are as follows:1.SDS-PAGE analysisDy10-m328SF showed faster mobility in SDS-PAGE than Dy10,and with equal mobility to Dy10 in 4 M urea-containing SDS-PAGE gel.2.Molecular cloning and sequence alignmentA pair of allele-specific PCR primers were used in accordance with the published HMW-GS gene sequences and used to amplify the complete coding sequence of y-type HMW-GS gene(Dy10 and Dy10-m328SF).The Dy10 gene sequence was identical to that of a sequence previously submitted to GenBank(accession no.X12929),The ORFs of Dy10-m328SF(Genbank No.KU934284)and Dy10 consisted of 1947 bp and encoded 648 amino acid residues.A missense mutation was identified in the mutant subunit,resulting in the replacement of serine(ser,S;the 328th residue)in Dy10 by phenylalanine(phe;F)in Dy10-m328SF.3.The predicted secondary structureThe software ANTHEPROT 6.6.1 and Online bioinformatics tools of CFSSP was used to predict the secondary structure of Dy10-m328SF and Dy10,including a-helix,?-sheet,?-turn and random coil conformations.The results show that the possibility of forming ?-helix,?-sheet and ?-turn neighboring the amino acid substitution differed.Therefore,we considered that the formation of more stable secondary structure that was not easily destroyed by a denaturant led to the faster mobility of Dy10-m328SF.4.Comparison and analysis of processing quality between materialsThere was no significant difference in protein content and Zeleny-sedimentation value of two materials in most experimental stations,but wet gluten content had significant differences;The change of the average parameters of two materials in different experimental stations were plotted by using the broken line graph.It can be seen that the protein content,Zeleny-sedimentation value and wet gluten content of PZ1-Dy10-m328SF are above PZ1,The bread quality traits were compared and found that the bread volume of PZ1-Dy 10-m328SF was higher than that of PZ1.