title: Molecular and characterization of NnPPO cDNA from lotus (Nelumbo nucifera) in rhizome browning.
abstract: The complete cDNA (NnPPO) of polyphenol oxidase in Nelumbo nucifera was successfully isolated, using Rapid amplification cDNA end (RACE) assays. The full-length cDNA of NnPPO was 2069 bp in size, containing a 1791 bp open reading frame coding 597 amino acids. The putative NnPPO possessed the conserved active sites and domains for PPO function. Phylogenetic analysis revealed that NnPPO shared high homology with PPO of high plants, and the homology modeling proved that NnPPO had the typical structure of PPO family. In order to characterize the role of NnPPO, Real-time PCR assay demonstrated that NnPPO mRNA was expressed in different tissues of N. nucifera including young leave, rhizome, flower, root and leafstalk, with the highest expression in rhizome. Patterns of NnPPO expression in rhizome illustrated its mRNA level was significantly elevated, which was consistent with the change of NnPPO activity during rhizome browning. Therefore, transcriptional activation of NnPPO was probably the main reason causing rhizome browning.
authors.affiliation: Henan University of Technology College of Biological Engineering Zhengzhou China.
authors.forename: C
authors.initials: C
authors.lastname: Dong
authors.affiliation: Wuhan University State Key Laboratory of Hybrid Rice, College of Life Science Wuhan China.
authors.forename: A Q
authors.initials: AQ
authors.lastname: Yu
authors.affiliation: Henan University of Technology College of Biological Engineering Zhengzhou China.
authors.forename: M G
authors.initials: MG
authors.lastname: Yang
authors.affiliation: Wuhan University Lotus Center Wuhan China.
authors.forename: M Q
authors.initials: MQ
authors.lastname: Zhou
authors.affiliation: Wuhan University State Key Laboratory of Hybrid Rice, College of Life Science Wuhan China huzhongli@whu.edu.cn.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Hu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004156:Catechol Oxidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D015416:Maillard Reaction; D008958:Models, Molecular; D031653:Nelumbo / Q000201:enzymology* / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D027343:Rhizome / Q000201:enzymology* / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; D004156:Catechol Oxidase