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小麦品质主要由籽粒贮藏蛋白的含量和类型决定，高分子量麦谷蛋白亚基(HMW-GSs)组合是决定加工品质的主要因素。为了解HMW-GSs组合完全一致、蛋白含量相似的两个品种面团稳定时间相差近一倍的原因（郑麦158：高面团强度；郑麦369：低面团强度），通过转录组测序比较了籽粒发育中期3个时间点（花后14 、21和28 d）的贮藏蛋白基因表达差异,分析了差异表达基因编码蛋白对面粉质量的贡献以及面粉的巯基含量差异等。结果表明，在3个时间点，两个品种间的HMW-GSs基因表达均无显著差异；郑麦158较郑麦369共有24个贮藏蛋白编码基因有显著表达差异，其中上调表达基因12个（23次），下调表达基因12个（23次）。12个显著上调表达基因中，包括9个燕麦类似蛋白基因（18次）、2个γ-醇溶蛋白基因(4次)和1个α-醇溶蛋白基因；在12个下调表达基因中，包括11个α-或α/β-醇溶蛋白基因（21次）和1个燕麦类似蛋白基因（2次）。两品种比较，郑麦158面粉的硫元素含量较低，但自由巯基和二硫键含量较高。基于蛋白二硫键预测和面粉蛋白质量评价模型分析结果，差异表达基因编码的燕麦类似蛋白和γ-醇溶蛋白对面团强度的贡献不低于优质HMW-GSs。推测燕麦类似蛋白与个别γ-醇溶蛋白可能是影响面团强度的重要蛋白；蛋白的高自由巯基含量是高面筋强度的分子基础。

英文摘要:

Combinations of high-molecular-weight glutenin subunits(HMW-GSs) are thought to be the major determinants of the visco-elastic properties of gluten in wheat. We compared the differentially expressed genes encoding wheat grain storage proteins(GSPs) between two cultivars with the same combinations of HMW-GSs and similar protein contents, but with contrasting dough stability time. We performed comparative transcriptomic analyses between two wheat cultivars, ZM158 (great dough strength) and ZM369(weak dough strength), at three grain-filling stages(14, 21 and 28 days-post-anthesis) and compared the sulfhydryl group content of the flour from the two cultivars. We also determined the contribution of the differentially expressed wheat GSP genes to the dough strength traits based on an evaluation model and prediction of disulfide bonds. The results showed that 24 GSP genes were significantly differentially expressed(46 times) between the two cultivars at the three grain-filling stages; 12 of them were up-regulated(23 times) and 12 were down-regulated(23 times), but there was no gene encoding HMW-GSs. The up-regulated GSP genes containednine avenin-like genes(18 times), two γ-gliadin genes(4 times), and one α-gliadin gene. The down-regulated genes contained 11 α-or α/β-gliadin genes(21 times) and one avenin-like gene(2 times).The prediction of protein disulfide bonds and the evaluation model of flour quality contribution indicated that the avenin-like proteins and γ-gliadin may contribute more to dough strength than the elite HMW-GSs. We also found there was lower sulfur content but higher free sulfhydryl group content in the flour from ZM158 compared with their content in the flour from ZM369. Consequently, combinations of HMW-GSs may not be the main contributors to flour strength properties, whereas avenin-like proteins and γ-gliadins are also important storage proteins related to dough strength. Furthermore, the high free sulfhydryl content of flour protein is the chemical basis of great dough strength.

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