综述了檵木属植物的植物学特征、生物学特征、分类及其主要功能成分黄酮类化合物、没食子酸和鞣质的研究进展。各种研究表明，檵木属植物的黄酮类化合物、没食子酸和鞣质成份有良好的药用价值，如，黄酮类化合物如甘草总黄酮提取物能降低高血脂的发病率，黄酮单体对金葡萄球菌、枯草杆菌、真菌等有很好的抑制作用；没食子酸可以抑制鸟苷酸脱羧酶(ODC)的促癌作用，能直接杀伤肿瘤细胞，还能抑制肿瘤血管的生长；鞣质具有广泛的药理活性，如保护消化器，治疗胃肠道出血，溃疡和水泻等。并对檵木属植物今后的研究方向进行了展望。

It summarized the botanical characteristics, the biological characteristics and the classification of Loropetalum plants, as well as the advances in main functional components of it, such as flavonoids, gallic acid and tannin. Each study indicated that the flavonoids, gallic acid and tannin in Loropetalum plants have great medicinal value, for instance, the flavonoids such as total flavonoids extracted from liquorice can reduce the incidence of hyperlipidemia, flavone monomer can greatly inhibit Staphylococcus aureus, Bacillus subtilis and fungi; gallic acid can inhibit the cancer-promoting action of ODC, can directly injure tumour cell, and also can inhibit the growth of tumour vessel; tannin has widely pharmacological activity, such as protecting digestive apparatus and treating gastrointestinal bleeding, ulcer and watery diarrhea. Moreover, it prospects the studying direction in the future.

多胺是一类小分子生物活性物质，广泛存在于生物体内，与植物的生长发育、衰老及抗逆性都有着密切的联系。就多胺合成途径中的两个关键酶基因，即S-腺苷甲硫氨酸合成酶基因（SAMS）和S-腺苷甲硫氨酸脱羧酶基因（SAMDC）的克隆、表达，以及转S-腺苷甲硫氨酸合成酶基因（SAMS）和转S-腺苷甲硫氨酸脱羧酶基因（SAMDC）表达调控等方面的研究进行回顾总结，并对其应用前景进行展望。

Polyamine is an important physiological regulation substance functioning in a wide variety of biological processes, such as plant growth, development, senescence and adversity stress tolerance, which widely exist in all living organisms. S-adenosylm ethionIne synthetase gene(SAMS)and S-adenosylmethionine decarboxylase gene(SAMDC)are the two key genes in the polyamine synthesis pathway. This paper summarized the gene cloning, expression and transgenic expression regulation of SAMS and SAMDC, and other aspects also reviewed. Its application prospect was discussed in the end.

目的分离珍稀濒危兰科药用铁皮石斛谷氨酸脱羧酶(GAD)基因并进行生物信息学和表达分析。方法采用RT-PCR和RACE技术获基因cDNA全长;利用生物信息学软件分析蛋白理化性质、结构域和三维建模等分子特性;用DNASTAR 6.0和MEGA 4.0分别进行氨基酸多序列比对和进化树分析;借助实时定量PCR检测基因表达。结果分离到DoGAD基因,cDNA全长1795 bp,编码一条由498个氨基酸组成的多肽,分子量55.90 kD,等电点5.32;DoGAD蛋白不含跨膜域或信号肽,具有谷氨酸脱羧酶和磷酸吡哆醛依赖的脱羧酶结构域(17-443、37-381);DoGAD与植物GADs蛋白一致性为69.5%~78.8%,隶属于GADs分子进化树的植物类群;DoGAD转录本在石斛叶和茎中相对表达量较高,分别为根中的5.16和3.92倍。结论成功克隆得到铁皮石斛谷氨酸脱羧酶基因全长,DoGAD的表达特征暗示其可能在铁皮石斛叶和茎中发挥重要的调控作用。

ObjectiveThis study is aimed to isolate and characterize a glutamate decarboxylase (GAD) geneDoGAD fromDendrobium officinale, a rare endangered medicinal orchid species. MethodsRT-PCR and RACE technologies were used for gene isolation. The physiochemical properties, conserved domains and three dimensional structure of the deduced DoGAD protein were determined using a series of bioinformatics tools. The analyses of multiple alignment and phylogenetic tree were performed using DNASTAR 6.0 and MEGA 4.0, respectively. Real time quantitative PCR was used for gene expression analysis.Results The full-length cDNA ofDoGAD, with 1795 bp in size, was deduced to encode a 498-aa protein with molecular weight of 55.90 kD and isoelectric point of 5.32. The deduced DoGAD protein, without transmembrane or signal peptide residues, contained glutamate decarboxylase and pyridoxal phosphate dependant decarboxylase domains (17-443, 37-381). DoGAD had high identities (69.5% - 78.8%) with a number

多胺具有调控细胞增殖、分化和凋亡的功能,可参与动物繁殖、胚胎发育以及癌症发生发展等多种生物学过程。在动物机体中,多胺稳态是通过多胺跨膜物质转运和多胺代谢途径共同维持的。溶质转运蛋白（SLC）基因家族中的SLC3A2、SLC7A1、SLC12A8、SLC22A16、SLC22A 1、SLC22A 2、SLC22A 3基因及其编码的蛋白质可参与多胺的跨膜物质转运;多胺代谢关键调控基因鸟氨酸脱羧酶（ODC）、鸟氨酸脱羧酶抗酶（OAZ）和鸟氨酸脱羧酶抗酶抑制剂（AZIN）对多胺跨膜物质转运也具有重要的调控功能;此外,金属阳离子、细胞膜跨膜电位和p H等内环境因素也可参与多胺转运的调节。因此,本文就多胺转运蛋白、多胺代谢相关基因和蛋白质以及内环境因素调控多胺跨膜物质转运的分子调控机制作一综述,以期为阐明多胺转运调控机制的研究奠定理论基础。

Polyamines are involved in several biological processes including reproduction, embryo development and cancer development, as well as play important roles in cell proliferation, differentiation and apoptosis. The homeostasis of polyamines is regulated strictly by transmembrane transporter and polyamine metabolically path-ways. Solute carrier ( SLC ) gene family including SLC3A2, SLC7A1, SLC12A8, SLC22A16, SLC22A1, SLC22A2 and SLC22A3 genes and their protein could involve in the process of polyamine transmembrane trans-port; furthermore, the key regulatory genes of polyamine metabolism including ornithine decarboxylase ( ODC ) , ornithine decarboxylase antizyme ( OAZ ) and ornithine decarboxylase antizyme inhibitorgenes ( AZIN) genes could also regulate transmembrane transport of polyamines;moreover, the internal environmen-tal factors including metal cation, transmembrane potential and pH also involved in the process of polyamine transport. Therefore, in this paper, the roles

通过SMARTRACE PCR技术获得了茶树中精氨酸脱羧酶(ADC)的cDNA全长序列,并登录GenBank(登录号为JQ653274)。ADC基因cDNA全长为2 988 bp,开放阅读框(ORF)全长为2 163 bp,共编码720个氨基酸,编码的蛋白质的分子量为77.430 kDa,理论等电点为5.373,其序列中不存在卷曲螺旋结构。ADC蛋白为亲水性非分泌不稳定蛋白,不跨膜运动,无信号肽序列存在,共有41个可能的磷酸化位点,存在于叶绿体基质中,是细胞质蛋白。精氨酸脱羧酶的基因cDNA全长序列的获得,对于进一步研究精氨酸在茶树氮代谢中的作用及茶氨酸代谢途径提供基础。

The full-length cDNA of arginine decarboxylase (ADC,GenBank accession No.JQ65327) gene was obtained by SMART RACE PCR method.It is 2 988 bp in length with an open reading frame (ORF) of 2 163 bp,encoding 720 amino acids with deduced molecular weight of 77.430 kDa and theoretical pI value of 5.373.Bioinformatics analysis show that ADC is a hydrophilic and unstable protein without any signal peptide,has no winded helix structure and transmembrane domain.There are 41 phosphorylation sites within the polypeptide chain.ADC is non-secreted protein and it functions in chloroplast stroma.The sequence analysis of ADC gene would bring some new clues for further exploration of the function of ADC in nitrogen metabolism and theanine biosynthesis.