title: Molecular characterization of fruit-specific class III peroxidase genes in tomato (Solanum lycopersicum).
abstract: In this study, expression of four peroxidase genes, LePrx09, LePrx17, LePrx35 and LePrxA, was identified in immature tomato fruits, and the function in the regulation of fruit growth was characterized. Analysis of amino acid sequences revealed that these genes code for class III peroxidases, containing B, D and F conserved domains, which bind heme groups, and a buried salt bridge motif. LePrx35 and LePrxA were identified as novel peroxidase genes in Solanum lycopersicum (L.). The temporal expression patterns at various fruit growth stages revealed that LePrx35 and LePrxA were expressed only in immature green (IMG) fruits, whereas LePrx17 and LePrx09 were expressed in both immature and mature green fruits. Tissue-specific expression profiles indicated that only LePrx09 was expressed in the mesocarp but not the inner tissue of immature fruits. The effects of hormone treatments and stresses on the four genes were examined; only the expression levels of LePrx17 and LePrx09 were altered. Transcription of LePrx17 was up-regulated by jasmonic acid (JA) and pathogen infection and expression of LePrx09 was induced by ethephon, salicylic acid (SA) and JA, in particular, as well as wounding, pathogen infection and H2O2 stress. Tomato plants over-expressing LePrx09 displayed enhanced resistance to H2O2 stress, suggesting that LePrx09 may participate in the H2O2 signaling pathway to regulate fruit growth and disease resistance in tomato fruits.
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei, Taiwan; Hualien District Agricultural Research and Extension Station, Council of Agriculture, Hualien, Taiwan.
authors.forename: Chii-Jeng
authors.initials: CJ
authors.lastname: Wang
authors.affiliation: AVRDC-The World Vegetable Center, PO Box 42, Shanhua, Tainan 74199, Taiwan.
authors.forename: Yuan-Li
authors.initials: YL
authors.lastname: Chan
authors.affiliation: Ecological Materials Technology Department, Green Energy & Eco-technology System Center, ITRI South Campus, Industrial Technology Research Institute, Tainan, Taiwan.
authors.forename: Chin Hui
authors.initials: CH
authors.lastname: Shien
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei, Taiwan. Electronic address: ykwbppp@ntu.edu.tw.
authors.forename: Kai-Wun
authors.initials: KW
authors.lastname: Yeh
mesh_terms: D000595:Amino Acid Sequence; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010544:Peroxidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D010940:Plant Proteins; D010544:Peroxidases
keywords: Class III peroxidases; H(2)O(2) stress; Plant hormone; Tomato; Wounding