小麦HMW-GS变异影响面筋蛋白结构及蛋白聚合体形成的机制研究

High-molecular-weight glutenin subunits(HMW-GS) are thought to be the most important components in the process of bread making because they determine gluten elasticity. A number of HMW-GS related to good quality have been applied in wheat quality breeding programs. However, the mechanism of HMW-GS variations affecting structure of gluten and formation of polymeric protein is still unknown. By using the HMW-GS near isogenic lines of wheat, this project aims to clarify the effects of HMW-GS variations on the secondary structure of gluten with FT-Raman spectroscopy analysis; to verify the effects of HMW-GS variations on the micro structure of gluten network with scanning electron microscopy; to clarify the bias of HMW-GS forming inter-molecular disulfide bonds by analysing the differences of the protein composition with LC-MS analysis; and to verify the effects of HMW-GS variations on the accumulation of SDS-unextractable polymeric protein. Based on the above studies, the principle of HMW-GS affecting the structure of gluten and the formation of inter-molecular disulfide bonds will be revealed, so as to understand the formation of polymeric protein thoroughly. Theoretical evidence will be provided for wheat quality breeding in the field of molecular structure of protein.

小麦高分子量麦谷蛋白亚基（HMW-GS）对面粉加工品质起决定作用，一些优质的HMW-GS已在小麦品质育种中得到广泛应用，但HMW-GS变异影响面筋蛋白结构及蛋白聚合体形成的分子机制尚不清楚。本项目将利用小麦HMW-GS近等基因系，借助傅里叶变换红外光谱技术，明确HMW-GS变异对面筋蛋白二级结构的影响；利用扫描电子显微技术，明确HMW-GS变异对面筋蛋白微观网络结构的影响；利用液相色谱-质谱联用技术，分析形成分子间二硫键的蛋白组成差异,明确不同 HMW-GS形成分子间二硫键的偏向性；利用排阻高效液相色谱技术，分析HMW-GS变异对不溶性蛋白聚合体积累动态的影响。根据以上四个方面的研究，揭示小麦HMW-GS变异影响面筋蛋白结构及分子间二硫键形成的机理，洞悉蛋白聚合体形成的分子机制，为分子结构领域小麦品质育种研究提供理论依据。

小麦高分子量麦谷蛋白亚基（HMW-GS）对面粉加工品质起决定作用，本项目以三套HMW-GS小麦近等基因系为材料，通过分析面筋蛋白二级结构、微观结构等，明确了同一遗传背景下，同一基因位点上HMW-GS变异对面筋蛋白二级结构、微观网络结构以及面团流变学特性的影响；分析了形成分子间二硫键的蛋白组成差异；探究了HMW-GS变异对UPP积累动态的影响，揭示了小麦HMW-GS变异影响面筋蛋白结构及分子间二硫键形成的机理，洞悉蛋白聚合体形成的分子机制，为研究小麦面粉品质的形成机制开辟了新的研究方向，对品质育种和农业生产具有十分重要的理论意义。通过对面筋蛋白二级结构、UPP含量以及面粉加工品质等指标进行的相关性分析，确立了面筋蛋白二级结构的指标可用于分析预测面筋蛋白特性及面粉品质，指导小麦品质分析与品质育种实践，对小麦品质遗传改良具有重要指导意义。