title: Ascorbate peroxidase gene family in tomato: its identification and characterization.
abstract: The antioxidative response, where ascorbate peroxidase (APX) is a key enzyme, is an integral part of the plant tolerance response to environmental stresses. As a first step towards the study of the physiological role and the regulation of the members of the Apx gene family, the orthologs of the stress-sensitive cultivated tomato Solanum lycopersicum cv. M82 (Slm) and of the wild salt-tolerant species S. pennellii acc. Atico (Spa) were identified by utilizing the tomato EST database, and characterized. A redundant list of 16 virtual Apx transcripts and four singleton ESTs was shown to correspond to seven genuine Apx genes. The complete tomato Apx gene family is comprised of genes encoding three cytosolic, two peroxisomal, and two chloroplastic APXs. These genes attained differential regulatory patterns in various Slm organs. More detailed study of Apx1 and Apx2 genes, that are the products of a recent gene duplication event, shows that they have already attained differential regulation within and between Slm and Spa under control and stress conditions. It is also suggested that due to lineage-specific gene duplication and lose events, intricate phylogenetic relationships exist among the members of the Apx gene families.
authors.affiliation: Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
authors.forename: Naim
authors.initials: N
authors.lastname: Najami
authors.forename: Tibor
authors.initials: T
authors.lastname: Janda
authors.forename: Waseim
authors.initials: W
authors.lastname: Barriah
authors.forename: Galya
authors.initials: G
authors.lastname: Kayam
authors.forename: Moshe
authors.initials: M
authors.lastname: Tal
authors.forename: Micha
authors.initials: M
authors.lastname: Guy
authors.forename: Micha
authors.initials: M
authors.lastname: Volokita
mesh_terms: D000595:Amino Acid Sequence; D060387:Ascorbate Peroxidases; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D005091:Exons; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D007438:Introns; D007527:Isoenzymes / Q000235:genetics; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010544:Peroxidases / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018744:DNA, Plant; D007527:Isoenzymes; D010940:Plant Proteins; D012333:RNA, Messenger; D010544:Peroxidases; D060387:Ascorbate Peroxidases