宁夏枸杞果实糖积累和蔗糖代谢相关酶活性的关系

通过对枸杞果实发育过程中果实生长模式、蔗糖、果糖、葡萄糖和淀粉含量及糖代谢相关酶活性的测定,研究了宁夏枸杞果实生长发育过程中糖的代谢积累与相关酶活性的关系.结果表明:(1)宁夏枸杞果实发育呈双S"曲线,果实主要以积累己糖为主.(2)蔗糖磷酸合成酶(SPS)活性在果实发育初期处于下降的趋势,在花后19d开始上升,果实转色后又逐渐下降;蔗糖合成酶(SS)活性总体表现为SS分解方向的活性大于SS合成方向的活性,说明枸杞果实发育过程中,SS的活性主要以分解方向的为主;酸性转化酶(AI)和中性转化酶(NI)的活性随果实发育呈上升趋势,但在果实成熟后期有所下降,且AI和NI活性高于合成酶类的活性,较高的转化酶类活性促进了果实内部己糖的积累.(3)在枸杞果实生长发育中,葡萄糖和果糖含量与AI和NI均呈极显著正相关,而与其它酶不具有相关性.说明AI和NI在宁夏枸杞果实的糖代谢中起着主要的调控作用.

Relationship between Sugar Accumulation and Its Metabolizing Enzymes in Lycium barbarum L.

The changes of growth phase,sucrose,glucose,fructose,starch and the activities of sugar metabolism-related enzymes in developing Lycium barbarum L.were determined to study the relationship between the sugar accumulation and its metabolizing enzymes in L.barbarum.The results indicated that:(1)the growth curves of L.barbarum showed double sigmoid pattern;the fruit of L.barbarum mainly accumulated glucose and fructose;(2)The activity of sucrose phosphate synthase sucrose phosphate synthase(SPS) was on the decrease in the early stage,increased on the nineteen days after blossom and gradually droped after veraison;The sucrose synthase sucrose synthase(SS) activity the cleavage direction was higher than that in the synthetic direction.It showed that the SS activity of cleavage direction was dominant in the developing L.barbarum.The acid invertase(AI) and the neutral invertase(NI) activities presented the trend of escalation along with the fruit growth,but droped in the fruit later mature period.The acid invertase(AI) and the neutralinvertase(NI) activities were higher than the sucrose synthesis enzymes activities.The higher invertase activity promoted the fruit glucose and fructose accumulation.(3)Throughout the whole fruit development,the content of glucose and fructose had significant positive correlations with the activities of acid invertase(AI) and neutral invertase(NI),but had no significant correlation with other enzymes.Its means that acid invertase(AI) and neutral invertase(NI) are playing the main regulative role in the L.barbarum fruit sugar metabolism.