title: Cloning, expression, and mapping of GDP-D-mannose pyrophosphorylase cDNA from tomato (Lycopersicon esculentum).
abstract: GDP-D-mannose pyrophosphorylase (GMP, EC 2.7.7.22) catalyzes the synthesis of GDP-D-mannose and represents the first committed step in plant ascorbic acid biosynthesis. Using potato GMP cDNA sequence as a querying probe, 65 highly homologous tomato ESTs were obtained from dbEST of GenBank and the putative cDNA sequence of tomato GMP was assembled. The full-length GMP cDNA of tomato was cloned by RACE-PCR with primers designed according to the assembled cDNA sequence. The full-length cDNA sequence contained a complete open reading frame (ORF) of 1,086 bp, which encoded 361 amino acid residues. This gene was designated as LeGMP (GenBank accession No. AY605668). Homology analysis of LeGMP showed a 96% identity with potato GMP and the deduced amino acid showed 99%, 97%, 91% and 89% homology with GMP from potato, tobacco, alfalfa and Arabidopsis thaliana, respectively. Northern blot analysis showed that LeGMP was constitutively expressed in roots, stems, leaves, flowers and fruits of tomato; but the expression levels varied. LeGMP was mapped to 3-D using 75 tomato introgression lines (ILs), each containing a single homozygous RFLP-defined chromosome segment from the green-fruited species Lycopersicon pennellii.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zou
authors.forename: Han-Xia
authors.initials: HX
authors.lastname: Li
authors.forename: Bo
authors.initials: B
authors.lastname: Ouyang
authors.forename: Jun-Hong
authors.initials: JH
authors.lastname: Zhang
authors.forename: Zhi-Biao
authors.initials: ZB
authors.lastname: Ye
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D009713:Nucleotidyltransferases; C026917:mannose 1-phosphate guanylyltransferase