title: Cloning and functional analysis of a novel ascorbate peroxidase (APX) gene from Anthurium andraeanum.
abstract: An 888-bp full-length ascorbate peroxidase (APX) complementary DNA (cDNA) gene was cloned from Anthurium andraeanum, and designated as AnAPX. It contains a 110-bp 5'-noncoding region, a 28-bp 3'-noncoding region, and a 750-bp open reading frame (ORF). This protein is hydrophilic with an aliphatic index of 81.64 and its structure consisting of α-helixes, β-turns, and random coils. The AnAPX protein showed 93%, 87%, 87%, 87%, and 86% similarities to the APX homologs from Zantedeschia aethiopica, Vitis pseudoreticulata, Gossypium hirsutum, Elaeis guineensis, and Zea mays, respectively. AnAPX gene transcript was measured non-significantly in roots, stems, leaves, spathes, and spadices by real-time polymerase chain reaction (RT-PCR) analysis. Interestingly, this gene expression was remarkably up-regulated in response to a cold stress under 6 °C, implying that AnAPX might play an important role in A. andraeanum tolerance to cold stress. To confirm this function we overexpressed AnAPX in tobacco plants by transformation with an AnAPX expression construct driven by CaMV 35S promoter. The transformed tobacco seedlings under 4 °C showed less electrolyte leakage (EL) and malondialdehyde (MDA) content than the control. The content of MDA was correlated with chilling tolerance in these transgenic plants. These results show that AnAPX can prevent the chilling challenged plant from cell membrane damage and ultimately enhance the plant cold tolerance.
authors.affiliation: College of Agriculture & Biotechnology, Zhejiang University, Hangzhou 310058, China; Research & Development Center of Flower, Zhejiang Academy of Agricultural Sciences, Hangzhou 311202, China; School of Agricultural and Food Science, Zhejiang A&F University, Lin'an 311300, China.
authors.forename: Hui-chun
authors.initials: HC
authors.lastname: Liu
authors.forename: Dan-qing
authors.initials: DQ
authors.lastname: Tian
authors.forename: Jian-xin
authors.initials: JX
authors.lastname: Liu
authors.forename: Guang-ying
authors.initials: GY
authors.lastname: Ma
authors.forename: Qing-cheng
authors.initials: QC
authors.lastname: Zou
authors.forename: Zhu-jun
authors.initials: ZJ
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D029064:Araceae / Q000502:physiology*; D060387:Ascorbate Peroxidases / Q000737:chemistry* / Q000235:genetics*; D003001:Cloning, Molecular / Q000379:methods*; D004789:Enzyme Activation; D004795:Enzyme Stability; D018869:Heat-Shock Response / Q000235:genetics*; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology*
chemical_list: D011994:Recombinant Proteins; D060387:Ascorbate Peroxidases