甜高粱茎秆贮存过程中蔗糖代谢及其相关酶活性的变化研究

为明确甜高粱茎秆贮存过程中蔗糖降解的关键酶，以期通过对蔗糖降解关键酶的分子调控解决甜高粱茎秆贮存过程中蔗糖易降解的难题。采用高效液相色谱法和酶学测定方法对3个品种甜高粱在采后75天贮藏期内，茎秆中的蔗糖、果糖、葡萄糖含量和可溶性酸性转化酶(SAI)、中性转化酶(NI)和蔗糖合成酶(SS)分解蔗糖的酶活性变化进行了测定。结果表明：在采后75天贮藏期内，‘辽甜1号’、‘辽甜4号’和‘辽甜6号’甜高粱的茎秆中，糖分降解迅速，总糖损失近一半，分别为68.2-31.9（g/100g干基）、43.0-18.1（g/100g干基）和59.6-25.3（g/100g干基）。3个品种果糖、葡萄糖和蔗糖含量呈总体下降趋势，并呈现贮藏期开始时糖分降低很快，而后缓慢降低的趋势。可溶性酸性转化酶活性在茎秆贮藏15天时增幅较大，而后以微小幅度持续增加，一直保持较高的酶活性。中性转化酶活性一直以微小幅度持续增加，酶活性较低，变化不大。蔗糖合成酶分解方向的活性则更低，且变化不大。这表明可溶性酸性转化酶可能与甜高粱茎秆贮存过程中蔗糖降解密切相关。

Studied on the Changes of Sucrose Metabolism and Related Activities of Enzymes During the Sweet Sorghum Storage

In order to understand the key invertase of sucrose degradation in stalk of sweet sorghum during storage.The changes of the content of sucrose,fructose and glucose and the activity of soluble acid invertase,neutral invertase and sucrose synthase from sweet sorghum stalk of Liaotian No.1,No.4 and No.6 were measured,using HPLC and enzyme assay method for after 75 days post-harvest storage.The results showed that the sugar decomposed rapidly during storage,then the total sugar lost nearly half,68.2-31.9 g/100 g dry basis,43.0-18.1 g/100 g dry basis and 59.6-25.3 g/100 g dry basis respectively.The trend of sucrose,fructose and glucose for these three species of sweet sorghum displayed a general downward,and the sugar reduced quickly after the beginning of storage period,then slowly decreased.The activity of soluble acid invertase had a significant increase at the first 15 days stem-storage,and increased in minor amplitude,while the enzyme kept a high activity during storage.The activity of neutral invertase kept increasing at small amplitude,but the enzyme activity stayed at a low level without significant changes.The activity of sucrose synthase of the decomposition direction was even lower,and with little change.This indicated that the acid invertase might be closely related to the sucrose degradation in sweet sorghum stalks during storage.