【摘要】 割手密(Saccharum spontaneum)属于甘蔗属细茎野生种,具有较强的抗逆性,是甘蔗育种的优良材料。过氧化物酶(POD)是活性氧系统(ROS)中的一个关键酶,是植物应对干旱胁迫的关键调控酶之一。利用同源克隆的方法 ,以割手密为材料,成功克隆2个POD等位基因序列(SsPOD-1a和SsPOD-1b,GenBank登录号为KJ002565和KJ002566)。经测序鉴定,这2个基因长度均为1 083 bp,其中包括27 bp的5′非编码区、60 bp的3′非编码区及一个996 bp的开放阅读框,共编码331个氨基酸,这2个等位基因的序列相似性为98.8%。蛋白质保守结构域分析结果表明,此2个基因均具有POD基因典型保守结构域,属于依赖于亚铁血红素Ⅲ型POD亚类。原核表达结果表明,这2个基因编码区能正常表达出目的蛋白,说明得到的这2个基因为功能基因,而不是假基因。POD基因分子系统分生分析结果表明,割手密POD基因与高粱、玉米、水稻等禾本科植物亲缘关系较近,与一些双子叶植物及裸子植物也有一定的亲缘关系,这也证实了POD基因起源较为古老且存在高度保守区。更多还原

【Abstract】 Saccharum spontaneum L. is a wild variety of sugarcane with tolerance to drought-stress and can be used in sugarcane breeding programs. Gene encoding peroxidases respond to stress-related signals and are believed to play key roles in these processes. In this study, two novel peroxidase(POD) allele genes(Ss POD-1a and Ss POD-1b) were cloned by using the homologous cloning strategy. Sequencing data showed both of the two cloned genes had 1 083 base pair, including 5′ untranslated regions 27 bp, 3′ untranslated regions 60 bp, and a 996 bp ORF,which coding 331 amino acid, and the similarity of the two allele gene is 98.8%. The structural domain of proteins analysis showed the two genic protein had typical well-conserved amino-acid residues about peroxidases, and were classified to heme containing class Ⅲ peroxidases. The protein expression experiment revealed that both of gene coding areas could express aim protein, indicating SsPOD-1a and Ss POD-1b were not pseudogene, but function genes. The phylogeny analysis indicated that peroxidase genes of S. spontaneum L. were similar to the grass family, including Sorghum bicolor, Zea maize and Oryza sativa, also had relationship to the dicotyledon plants,even to some gymnosperms, vertifying the origin of peroxidase genes are old and exist well-conserved region.更多还原