肉苁蓉和寄主梭梭体内可溶性糖分积累与蔗糖代谢相关酶活性研究

通过测定不同发育时期肉苁蓉和寄主梭梭体内主要糖类物质含量和蔗糖代谢相关酶活性,以研究寄生植物与寄主植物的糖代谢及其关系。结果表明:未寄生肉苁蓉的梭梭以积累葡萄糖为主,而寄生肉苁蓉的梭梭在夏季休眠期以积累葡萄糖为主,进入秋季旺盛生长期时以积累蔗糖为主。肉苁蓉的糖分积累与梭梭不同,己糖含量约占可溶性总糖的62.45%,而蔗糖仅为可溶性总糖的4.98%,故肉苁蓉为己糖积累型。寄主梭梭同化枝内蔗糖磷酸合成酶活性较转化酶活性和蔗糖合成酶活性低,其中寄生肉苁蓉的梭梭的分解酶类活性高于未寄生肉苁蓉的梭梭。肉苁蓉体内转化酶活性较低,而蔗糖合成酶和蔗糖磷酸合成酶活性较高,且蔗糖合成酶活性高于蔗糖磷酸合成酶活性,表现为肉苁蓉中的分解酶类活性高于合成酶类活性,较高的分解酶类活性促进了蔗糖的分解,从而促进了糖分由寄主梭梭向肉苁蓉的不断转移。总体来看,肉苁蓉和寄主梭梭体内糖分的代谢主要以蔗糖合成酶为主,其它2种酶为辅协同参与调控。

Soluble Sugar Accumulation and the Activities of Sugar Metabolism related Enzymes in Cistanche deserticola and Its Host Haloxylon ammodendron

The contents of major soluble sugars and the activities of sugar metabolism-related enzymes at different developmental stages in Cistanche deserticola and its host Haloxylon ammodendron were determined to study sugar metabolisms and their relations of C.deserticola and its host H.ammodendron.The results showed that C.deserticola and its host H.ammodendron without suffering C.deserticola parasitization mainly accumulated glucose and H.ammodendron suffering C.deserticola parasitization mainly accumulated glucose during the overwintering period and sucrose during the vigorous growth in summer.C.deserticola differed from H.ammodendron in sugar accumulation and its hexose sucroseseparately accounted of 62.45% and 4.98% of its soluble sugar content thus belonging to the type of hexose accumulation.In the assimilating shoots of H.ammodendron,the activity of sucrose phosphate synthase was lower than those of sucrose synthase and invertase and,the activities of clastic enzymes in H.ammodendron suffering C.deserticola parasitization were higher than those \%H.ammodendron\% without suffering C.deserticola parasitization.In C.deserticola,the activities of invertases were low and the activities of sucrose synthase and sucrose phosphate synthase were high, and the activity of sucrose synthase was higher than that of sucrose phosphate synthase, which appeared,which was manifested in that in C.deserticola,the activities of clastic enzymes were higher than that of synthases and the higher activities of clastic enzymes improved sucrose breakdown thus enhancing the transfer of sugar from H.ammodendron to C.deserticola.Summarily,in sugar metabolisms of C.deserticola and its host H.ammodendron,sucrose synthase played a principal role and the other two enzymes played a secondary and regulating role.