title: Molecular cloning of a putative gene encoding isopentenyltransferase from pingyitiancha (Malus hupehensis) and characterization of its response to nitrate.
abstract: A putative isopentenyltransferase (IPT) encoding gene was identified from a pingyitiancha (Malus hupehensis Rehd.) expressed sequence tag database, and the full-length gene was cloned by RACE. Based on expression profile and sequence alignment, the nucleotide sequence of the clone, named MhIPT3, was most similar to AtIPT3, an IPT gene in Arabidopsis. The full-length cDNA contained a 963-bp open reading frame encoding a protein of 321 amino acids with a molecular mass of 37.3 kDa. Sequence analysis of genomic DNA revealed the absence of introns in the frame. Quantitative real-time PCR analysis demonstrated that the gene was expressed in roots, stems and leaves. Application of nitrate to roots of nitrogen-deprived seedlings strongly induced expression of MhIPT3 and was accompanied by the accumulation of cytokinins, whereas MhIPT3 expression was little affected by ammonium application to roots of nitrogen-deprived seedlings. Application of nitrate to leaves also up-regulated the expression of MhIPT3 and corresponded closely with the accumulation of isopentyladenine and isopentyladenosine in leaves.
authors.affiliation: College of Horticulture Science and Engineering/State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Peng
authors.forename: Futian
authors.initials: F
authors.lastname: Peng
authors.forename: Chunfu
authors.initials: C
authors.lastname: Zhu
authors.forename: Shaochong
authors.initials: S
authors.lastname: Wei
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D020224:Expressed Sequence Tags; D017343:Genes, Plant / Q000187:drug effects; D027845:Malus / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000494:pharmacology*; D016366:Open Reading Frames; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D009566:Nitrates; D019883:Alkyl and Aryl Transferases; C024274:adenylate isopentenyltransferase