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木薯(Manihot esculenta Crantz)为大戟科植物,其块根富含淀粉,主要用于食用、饲用,同时木薯淀粉还可广泛应用于工业生产中.木薯块根淀粉的合成需要蔗糖提供碳水化合物和能量,碱性/中性转化酶在木薯块根蔗糖分解利用时起关键作用.前期已从木薯基因组中克隆获得了11个碱性/中性转化酶基因,其中MeNINV4主要在茎中表达.本研究主要利用转化酶酵母突变菌株SEY2102进行酵母功能互补实验,鉴定MeNINV4是否具有催化蔗糖分解的功能.结果发现,转了pDR196-MeNINV4的SEY2102酵母可以在以蔗糖为唯一碳源的培养基中生长,表明MeNINV4能催化分解蔗糖.提取含有pDR196-MeNINV4质粒的SEY2102酵母粗酶液,进行碱性/中性转化酶活性检测,发现其能催化蔗糖分解成还原糖.这些结果为进一步研究MeNINV4的酶学特性及生理功能提供参考.“,”Cassava (Manihot esculenta crantz) is the Euphorbiaceae plants and its tuber root is rich in starch.Cassava is mainly use for food,feed,while also be widely used in industrial production.Sucrose provides carbohydrate and energy for the synthesis of cassava tuberous starch.The Alkaline/Neutral invertase is a key enzyme for the decomposition of sucrose in cassava.Presently,11 Alkaline/Neutral invertase genes were cloned from the cassava genome,and the expression of MeNINV4 was high in stem.In this study,we used invertase mutant yeast strain SEY2102 to perform yeast functional complementation experiment to determine whether MeNINV4 had the function of catalyzing the decomposition of sucrose.The results showed that SEY2102 yeast with pDR196-MeNINV4 vector could grow in medium with sucrose as the sole carbon source,indicating that MeNINV4 could atalyze the decomposition of sucrose.The crude enzyme of SEY2102 yeast containing pDR196-MeNINV4 vector was extracted,and the Alkaline/Neutral activity was detected.It was found that it could catalyze the decomposition of sucrose into reducing sugar.These results could provide the basis for further study of the enzymatic properties and physiological functions of MeNINV4.