Deletion of high-molecular-weight glutenin subunits in wheat significantly reduced dough strength and bread-baking quality

BMC Plant Biology

Yuping Liu¹  Xiyong Chen¹  Lijing Sun¹  Mengyun Hu¹  Yingjun Zhang¹  Qian Liu¹  Liangjie Lv¹  Hui Li¹  Xu Jia² 

[1] Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences;Institute of Genetics and Developmental Biology, Chinese Academy of Sciences;

关键词: Common wheat;    High-molecular-weight glutenin subunits;    Post-transcriptional gene silencing;    Glutenin macropolymer;    Gliadin content;    Dough quality;   

DOI  :  10.1186/s12870-018-1530-z

来源: DOAJ

【 摘 要 】

Abstract Background High-molecular-weight glutenin subunits (HMW-GS) play important roles in the elasticity of dough made from wheat. The HMW-GS null line is useful for studying the contribution of HMW-GS to the end-use quality of wheat. Methods In a previous work, we cloned the Glu-1E b x gene from Thinopyrum bessarabicum and introduced it into the wheat cultivar, Bobwhite. In addition to lines expressing the Glu-1E b x gene, we also obtained a transgenic line (LH-11) with all the HMW-GS genes silenced. The HMW-GS deletion was stably inherited as a dominant and conformed to Mendel’s laws. Expression levels of HMW-GS were determined by RT-PCR and epigenetic changes in methylation patterns and small RNAs were analyzed. Glutenins and gliadins were separated and quantitated by reversed-phase ultra-performance liquid chromatography. Measurement of glutenin macropolymer, and analysis of agronomic traits and end-use quality were also performed. Results DNA methylation and the presence of small double-stranded RNA may be the causes of post-transcriptional gene silencing in LH-11. The accumulation rate and final content of glutenin macropolymer (GMP) in LH-11 were significantly lower than in wild-type (WT) Bobwhite. The total protein content was not significantly affected as the total gliadin content increased in LH-11 compared to WT. Deletion of HMW-GS also changed the content of different gliadin fractions. The ratio of ω-gliadin increased, whereas α/β- and γ-gliadins declined in LH-11. The wet gluten content, sedimentation value, development time and stability time of LH-11 were remarkably lower than that of Bobwhite. Bread cannot be made using the flour of LH-11. Conclusions Post-transcriptional gene silencing through epigenetic changes and RNA inhibition appear to be the causes for the gene expression deficiency in the transgenic line LH-11. The silencing of HMW-GW in LH-11 significantly reduced the dough properties, GMP content, wet gluten content, sedimentation value, development time and stability time of flour made from this wheat cultivar. The HMW-GS null line may provide a potential material for biscuit-making because of its low dough strength.

【 授权许可】

Unknown