Abstract: Two wheat cultivars Zhengmai 158 and Zhengmai 119 with same combinations of high molecular weight glutenin subunits（HMW‑GS）but quite different dough strength and protein content（Zhengmai 158 with high dough strength and low protein content，Zhengmai 119 with low dough strength and high protein content） were used as materials.At 14，21 and 28 days after flowering，grain transcriptome sequencing was performed，and differentially expressed grain storage protein（GSP）genes，sulfur and sulfhydryl contents of the flour，cysteine and free sulfhydryl contents in proteins encoded by differentially expressed GSP genes between the two wheat cultivars were analyzed，so as to explore the possible reasons for the difference of flour quality under the same HMW‑GS combination.The results showed that compared with Zhengmai 119，Zhengmai 158 had lower total proteins and higher gluten index and stabilization time；the two cultivars had same combinations of HMW‑GS，and the expression levels of high and low molecular weight glutenin subunit genes were not significantly different between the two cultivars；twenty‑eight GSP genes were significantly differentially expressed between the two cultivars at the three time points，5（3 avenin‑like genes and 2 gliadin genes）of them were significantly up‑regulated in Zhengmai 158，and 23（16 gliadin genes，5 avenin‑like genes and 2 globulin genes）of them were significantly down‑regulated in Zhengmai 158. There was lower sulfur content，higher contents of free sulfhydryl，total sulfhydryl and disulphide bonds in the flour from Zhengmai 158 than thoes from Zhengmai 119，and the contents of predicted cysteine and free sulfhydryl in proteins encoded by up‑regulated expressed GSP genes in Zhengmai 158 were higher.Consequently，combinations of HMW‑GS may not be the main contributor to flour strength，decreasing the expression level of gliadin genes is an effective measure to improve the dough strength，individual gliadin genes and avenin‑like genes may be closely related to dough strength，and high free sulfhydryl content is the molecular basis of high dough strength.

Key words: Wheat, Storage protein, Dough strength, Free sulfhydryl, Differentially expressed gene

摘要： 以2个高分子质量麦谷蛋白亚基（HMW-GS）组合完全一致但籽粒蛋白质含量和面团强度有较大差异的小麦品种（郑麦158：低蛋白质含量、高面团强度；郑麦119：高蛋白质含量、低面团强度）为试验材料，分别在开花后14、21、28 d，对其籽粒进行转录组测序，分析3个时间点2个品种间差异表达的贮藏蛋白基因、面粉中硫和巯基含量及差异表达基因编码蛋白质的半胱氨酸和自由巯基含量，以探讨HMWGS组合相同情况下面粉质量差异的可能原因。结果表明，郑麦158的籽粒总蛋白质含量较低，但面筋指数、面团稳定时间较高；2个品种的HMW-GS组合完全一致，而且高、低分子质量麦谷蛋白亚基基因表达量无显著差异；筛选出28个显著差异表达的贮藏蛋白基因，其中，5个基因（3个类燕麦贮藏蛋白和2个醇溶蛋白基因）在郑麦158中表达量显著上调，23个基因（16个醇溶蛋白基因、5个类燕麦贮藏蛋白基因和2个球蛋白基因）在郑麦158中表达量显著下调；郑麦158面粉中硫元素含量较低，但自由巯基、总巯基和二硫键含量较高，且郑麦158中上调表达贮藏蛋白基因编码蛋白质的半胱氨酸、自由巯基含量均较高。综上，HMW-GS组合可能不是决定面团强度的主要因素，降低醇溶蛋白基因的表达量是提高面团强度的有效措施，个别醇溶蛋白和类燕麦贮藏蛋白可能与面团强度密切相关，高自由巯基含量是高面团强度的分子基础。

关键词: 小麦, 贮藏蛋白, 面团强度, 自由巯基, 差异表达基因