摘要
为揭示C4野生植物稗草(Echinochloa crusgalli)PEPCase的结构和功能特点,探索改善作物高光效新途径,克隆了稗草(E.crusgalli)磷酸烯醇式丙酮酸羧化酶基因(ppc)的cDNA全长,测序及同源性比较分析结果证实,稗草ppc的cDNA全长为2 886 bp,编码961个氨基酸(GenBank登录号:AY251482);核苷酸序列与谷子(Setaria italica)C3型、高粱(Sorghumbicolor)C3-2型、玉米(Zea mays)C3-2型、水稻(Oryza sativa)C3型磷酸烯醇式丙酮酸羧化酶基因的同源率分别达94.8%、93.2%9、3.0%和89.7%。推导的氨基酸序列中C末端第771位氨基酸是丙氨酸(A),表明是一个C3型基因。与其他植物几种不同形式PEPCase进行的多重序列比对与系统进化分析结果也证实,此基因的核苷酸序列及其编码的氨基酸序列与所有参与对比的C3型序列的同源性均远远高于与C4型的同源性。与玉米、高粱C3-2型PEPCase的同源性分别高达96.5%9、6.4%,与高粱、玉米的C3-1型PEPCase的同源性分别为84.3%、83.8%,而与谷子、玉米、甘蔗和高粱的C4型PEPCase的一致性相对较低,分别为82.2%、79.1%、77.1%和76.6%。因此进一步推论新克隆的稗草ppc基因属于C3-2型。对其编码的蛋白序列进行了结构域、活性位点和功能位点预测。
Phosphoenolpyruvate carboxylase （PEPCase） has a variety of functions in plants. In order to elucidate structural and functional characters of PEPCase from Echinochloa crusgalli, and search a new approach to improve crops photosynthesis, a full-length cDNA for PEPCase was isolated from E. crusgalli. Using the program of Blast on NCBI GenBank database, the sequence presented a very high match with the genes from other plants. After alignment on ClustalW program, the identities of the cloned fragment with PEPCase genes from Setaria italica C3 -form, Sorghum valgare C4- form, Zea mays C4- form and Oryza sativa C3 - form were about 94.8 %, 93.2 %, 93.0 % and 89.7 %, respectively. E. crusgalli ppc ORF is 2 886 bp, encoding 961 amino acid residues. The sequence has been submitted to the GenBank database, the accession number is AY251482. Alignment and phylogenetic analysis of the amino acid sequence deduced from the fragment and the PEPCase sequences of other plants retrieved from GenBank were carried out by ClustalW program, which showed that the sequences homology of E. crusgaUi with C3- form was higher than with C4- form. To identify amino acid residues and/or domains responsible for C4/ C3-specific properties, we found the putative amino acid sequence contains a C3 conserved alanine at position 771, and the sequence shared a homology of 96.5 %, 96.4 % with the C3-2- form PEPCase of Zea mays and Sorghum valgare,83.8%, 84.3% with the C3-1- form PEPCase of Zea mays and Sorghum valgare, and 82.2%, 79.1%, 77.1%, 76.6% with the C4. form PEPCase of S. italica, Z. mays, S. spontaneum and Sorghum valgare. In conclusion, the cloned sequence is a C3-2- form of PEPCase gene from E. crusgalli. The domain, active sites and fuction sites of Echinochloa crusgalli PEPC protein are predicted.
出处
《作物学报》
CAS
CSCD
北大核心
2005年第10期1365-1369,共5页
Acta Agronomica Sinica
基金
国家重点基础研究和发展规划(973)项目:作物高效抗旱的分子生物学及遗传学基础(2003CB114300)
作物抗旱的遗传学基础(2003CB114301)
国家研究与开发专项(863):优质
抗逆转基因新品种(系)的选育与转基因技术创新研究(JY03-B-11)
关键词
稗草
磷酸烯醇式丙酮酸羧化酶
基因克隆与分析
Echinochloa crusgalli
Phosphoenolpyruvate carboxylase （PEPCase）
Gene cloning and characterization
