中文摘要：

大豆种子萌发过程中，外界环境在很大程度上影响了种子内部蛋白的变化，其中pH值是非常重要的影响因子之一。本试验研究了不同萌发pH值条件下大豆种子相对吸水量、发芽率、可溶性蛋白质、肽、氨态氮含量、内肽酶和外肽酶活性等生理生化指标的变化，探讨pH值对蛋白质代谢的影响。结果表明：在pH6．0和pH8．0条件下种子吸水速率最快，pH8．0时萌发率最高；对于可溶性蛋白质含量来讲，pH6．0时的含量最高，当pH值升高到7．5时含量达到最低值。另外，试验过程中内肽酶和外肽酶的活性最高时的pH值分别为6．0及9．0，而蛋白降解产物——肽和氨基酸含量达到最大值时的pH值分别为9．0和6．0。试验为继续研究种子萌发过程中物质的变化奠定基础，同时也为在生理生化水平上充分了解种子萌发过程提供理论依据。

英文摘要：

In the process of soybean seed germination, external environment greatly influences internal protein change of seeds, pH is a very important factor. This study under the condition of different pH during soybean seed germinating, studied the relative water quantity, soluble protein and ammonia nitrogen content, activity of protease and peptidase etc, and physiological and biochemical indexes changes, to explore the effect of pH on protein metabolism. Results showed that water uptake was the fastest at pH 6.0 and pH 8.0, and germination rate was the largest at pH 8.0. Soluble protein content was the highest at pH 6.0, when pH up to 7.5, It＇ s content decreased to the lowest. In addition, the activity of protease and peptidase was the highest when pH 6.0 and 9.0 during experiment,and protein degradation products-peptide and amino acid content was the highest at pH 6.0 and 9.0 respectively. In all, this research supplied a foundation to further study the process of seed germination on one hand, on the other hand, this research provided theory basis for understanding seed germi- nation process at physiological and biochemical levels.