普甜玉米种子萌发期糖代谢和水解酶活性动态变化

Dynamic analysis for glucose mobilization and hydrolytic enzyme activity at different germination stages in sweet corn

关键词:  甜玉米  糖代谢  动态分析  种子萌发  种子物质利用率

Key words:  sweet corn  glucose mobilization  dynamic analysis  seed germination  seed reserve utilization efficiency

摘要:

种子萌发是一个较复杂的生理生化过程,是种子贮藏物质在酶的作用下经过一系列反应生成蔗糖、葡萄糖、果糖等各种糖类化合物,为种子萌发提供碳源和能量。该研究利用两个不同来源、籽粒营养成分具有差异的普甜玉米种子动态分析了种子萌发期蔗糖、果糖和葡萄糖代谢及关键水解酶活性的变化。结果表明:在种子萌发过程中,E22和T26两个普甜玉米种子的物质动员量、物质利用率、蔗糖、葡萄糖和果糖含量均存在遗传差异,其中淀粉含量较高的T26种子具有较突出的物质利用率,表明淀粉是影响普通甜玉米种子萌发的关键因子; 在种子萌发4～8 d、6～10 d时,E22分别具有较高的蔗糖和葡萄糖含量,而T26是在萌发10 d时具有较高的果糖含量。随着种子发芽进程,蔗糖合成酶活性、淀粉酶活性都呈逐渐上升的趋势,但淀粉酶活性变幅较明显; 进一步关联分析8个种子萌发物质利用性状间关系,结果表明种子萌发期间,种子物质动员量主要受淀粉酶活性影响,而种子物质利用率则主要受糖含量多少制约。因此,提高甜玉米种子萌发期物质利用率对其种子发芽和幼苗生长,增强其与杂草生长的竞争力,提高甜玉米产量均具有重要意义。

Abstract:

Seed germination is a complex physiological and biochemical process that the storage material is broken into sucrose,glucose and other sugars compounds under the action of enzyme reaction in order to provide the carbon source and energy for seedling growth. In this study,the dynamics of storage carbohydrate mobilization,sucrose synthase activity and amylase were analyzed at different seed germination stages by using two different seeds that the grain nutrients are different are from different countries in sweet corn. The results showed that there were significant differences for storage carbohydrate mobilization between E22 and T26 including the mobilized seed reserve,seed reserve utilization,sucrose,glucose and fructose content. Starch is the key factor of seed germination in sweet corn because of the outstanding material utilization in T26. By comparison,the mobilized seed reserve in T26 was lower,while the seed reserve utilization efficiency was higher. During seed germination,sucrose and glucose contents were higher for E22 in 4-8 d and 6-10 d,while fructose content was higher for T26 in 10 d. Amylases and sucrose synthase activities were increased durining the process of seed germination. Grey correlation analysis showed that the mobilized seed reserve was affected by the amylases during seed germination and seed reserve utilization was constrained by sucrose content,glucose content and fructose content. Improving of seed reserve utilization in sweet corn is of great significance to strengthen the seed germination and seedling growth,to enhance its competitiveness with weeds and to increase production.