铁皮石斛甘露聚糖重要调节MSR的研究进展
摘要：铁皮石斛为兰科石斛属多年附生草本，以新鲜或干燥茎入药，具有具有滋阴清热、益胃生津、明目强腰等功效，铁皮石斛活性成分种类多，药理作用范围广，研究发现，铁皮石斛的活性物质为多糖、生物碱、黄酮、萜类等，其中由甘露糖、葡萄糖和少量半乳糖组成的铁皮石斛多糖具有抗氧化、抗肿瘤、抗炎等生物活性。多糖结构复杂，与其药理活性密切相关，对于铁皮石斛多糖生物合成途径的解析也一直都是研究热点。铁皮石斛甘露糖的合成与何种基因有关？前人以豆科植物种子为模型系统，对瓜尔豆中纤维素合成酶样A（CSLA）基因编码的甘露聚糖合成酶进行了鉴定和鉴定，分析拟南芥CSLA突变体和过表达植株进一步证实CSLA蛋白在体内具有葡甘聚糖合成酶的功能。随着国内海外对相关基因的深入研究，有研究报道了胡芦巴MSR(Mannan Stnthesisi Related)基因(TfMSR)及其两个拟南芥同源基因AtMSR1和AtMSR2的特性，结果表明MSR蛋白对甘露聚糖的生物合成具有重要作用，铁皮石斛中也存在着同源基因DcMSR,该基因又会对铁皮石斛甘露聚糖合成产生怎样的影响？本文综述前人对甘聚糖合成相关基因的研究成果，为将来研究铁皮石斛甘露糖合成提供理论依据。
关键词：铁皮石斛； 甘露聚糖； MSR基因； CSLA基因
Research Progress on Important Regulation of MSR by Mannan from Dendrobium Officinale
Abstract:Dendrobium officinale is a perennial epiphytic herb of dendrobium orchidaceae. Fresh or dried stems are used as medicine. Dendrobium officinale has the effects of nourishing Yin and clearing heat, nourishing stomach and promoting body fluid, strengthening eyes and strengthening waist, etc. There are many kinds of active components and a wide range of pharmacological effects.Dendrobium officinale polysaccharide, which consists of mannose, glucose and a small amount of galactose, has antioxidant, anti-tumor and anti-inflammatory activities.The complex structure of polysaccharides is closely related to their pharmacological activities. The analysis of biosynthesis pathway of polysaccharides from Dendrobium officinale has always been a research focus.So what genes are involved in the synthesis of mannose from Dendrobium officinale?Previous studies have identified mannose synthase encoded by cellulose synthase-like A (CSLA) gene in guar bean using leguminous seeds as A model system. Analysis of ARABidopsis CSLA mutants and overexpressed plants further confirmed that CSLA protein has the function of glucomannan synthase in vivo.With the in-depth research on Related genes at home and abroad, some studies have reported the characteristics of MSR(Mannan Stnthesisi Related gene) and its two arabidopsis homologous genes AtMSR1 and AtMSR2. The results show that MSR protein plays an important role in the biosynthesis of Mannan.DcMSR also exists in Dendrobium officinale.This paper reviews the previous studies on the genes related to glycan synthesis and provides theoretical basis for future studies on mannose synthesis of Dendrobium officinale.
1种质资源与甘露聚糖
1.1铁皮石斛
铁皮石斛是我国传统的名贵中药，其药用价值备受历代医者推崇，享有“救命仙草”的美称。多与苔鲜植物、卷柏、地衣等附着在高山峻岭的悬崖峭壁和岩石缝隙中，裸露的须根从空气中水分[1]。铁皮石斛具有很高的观赏价值，也有着很高的药用价值，被《道藏》誉为“中华九大仙草之首”,主要分布于我国的安徽、浙江、云南、贵州、四川等地[2]。
1.2甘露聚糖
