三种滇黄精资源多糖及代谢相关酶活性的关系

Relationships between polysaccharide and metabolism-related enzyme activities in three Polygonatum kingianum germplasms

【目的】黄精多糖是黄精的主要活性成分,研究滇黄精种质资源多糖变化规律与其代谢酶活性的相关性,了解差异种质滇黄精多糖积累差异的生理基础,对滇黄精良种选育、质量控制和道地药材品质挖掘有着重要意义。【方法】采用紫外分光光度计法和高效液相色谱法测定云南省13份滇黄精资源的多糖含量,筛选其中3种多糖含量显著差异的滇黄精种质,测定其果糖、蔗糖和葡萄糖含量变化特征,以及蔗糖合成酶、磷酸蔗糖合成酶、尿苷二磷酸葡萄糖焦磷酸化酶、酸性转化酶和中性转化酶的酶活性,并分析多糖含量变化与糖代谢酶活性的相关性。【结果】云南省13份滇黄精种质的多糖含量差异显著,含量变化为7.63%~29.36%;对多糖低含量(H1)、中含量(H9)和高含量(H12)的3份差异种质滇黄精进行分析发现,其蔗糖、果糖和葡萄糖含量均存在显著差异,含量由高到低顺序为蔗糖>果糖>葡萄糖,且其含量随多糖含量的增加而增加;5种酶活性由高到低顺序为中性转化酶>酸性转化酶>磷酸蔗糖合成酶>蔗糖合成酶>尿苷二磷酸葡萄糖焦磷酸化酶,且酶活性随多糖含量升高而升高;蔗糖含量与尿苷二磷酸葡萄糖焦磷酸化酶活性呈极显著正相关(P<0.01);蔗糖含量与中性转化酶活性呈显著正相关(P<0.05);中性转化酶活性与尿苷二磷酸葡萄糖焦磷酸化酶活性呈显著正相关(P<0.05)。【结论】推测尿苷二磷酸葡萄糖焦磷酸化酶UGPase、中性转化酶NI是不同种质滇黄精多糖合成的关键酶。

【Objective】Polysaccharide was the main active component of Polygonatum kingianum.Studying the correlation between the polysaccharide variation pattern and their metabolic enzyme activities,and understanding the physiology of polysaccharide accumulation differences among different germplasms of P.kingianum,were of great significance to breeding,quality control,and excavation of authentic herbs.【Method】The polysaccharide contents of thirteen P.kingianum germplasms in Yunnan province were determined by ultraviolet spectrophotometer and high performance liquid chromatography(HPLC)methods.Of these,three germplasms with significantly different polysaccharide contents were screened,and the contents of fructose,sucrose,and glucose,as well as the enzymatic activities of sucrose synthetase(SS),sucrose phosphate synthase(SPS),uridine diphosphate glucose pyrophosphorylase(UGPase),acid invertase(AI)and neutral invertase(NI)were determined.Also,the correlation between the changes in polysaccharide contents and activities of sugar metabolizing enzymes in P.kingianum was analyzed.【Result】There were significant differences in the polysaccharide contents among thirteen germplasms of P.kingianum,and the variations were from 7.63%to 29.36%.The three different P.kingianum with low(H1),medium(H9)and high(H12)polysaccharide contents revealed that there were significant differences in sucrose,fructose,and glucosecontents with sucrose>fructose>glucose in descending order.Their contents increased with increasing polysaccharide contents.The activities of five sugar metabolism enzymes in descending order were NI>AI>SPS>SS>UGPase,and the enzyme activities increased with increasing polysaccharide content.Sucrose content was significantly positively correlated with the activity of UGPase(P<0.01).Sucrose content was positively correlated with the activity of NI(P<0.05).And the activity of NI was positively correlated with that of UGPase I(P<0.05).【Conclusion】UGPase and NI were supposed to be key enzymes for the polysaccharide biosynthesis of P.kingianum.