Molecular cloning and characterization of apricot fruit polyphenol oxidase.
A reverse transcriptase-polymerase chain reaction experiment was done to synthesize a homologous polyphenol oxidase (PPO) probe from apricot (Prunus armeniaca var Bergeron) fruit. This probe was further used to isolate a full-length PPO cDNA, PA-PPO (accession no. AF020786), from an immature-green fruit cDNA library. PA-PPO is 2070 bp long and contains a single open reading frame encoding a PPO precursor peptide of 597 amino acids with a calculated molecular mass of 67.1 kD and an isoelectric point of 6.84. The mature protein has a predicted molecular mass of 56.2 kD and an isoelectric point of 5.84. PA-PPO belongs to a multigene family. The gene is highly expressed in young, immature-green fruit and is turned off early in the ripening process. The ratio of PPO protein to total proteins per fruit apparently remains stable regardless of the stage of development, whereas PPO specific activity peaks at the breaker stage. These results suggest that, in addition to a transcriptional control of PPO expression, other regulation factors such as translational and posttranslational controls also occur.
Chevalier
T
T
Institut National de la Recherche Agronomique, Site Agroparc, Domaine Saint Paul, Station de Technologie des Produits Végétaux, 84914 Avignon cedex 9, France.
de Rigal
D
D
Mbéguié-A-Mbéguié
D
D
Gauillard
F
F
Richard-Forget
F
F
Fils-Lycaon
B R
BR
D000595:Amino Acid Sequence; D001483:Base Sequence; D004156:Catechol Oxidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D005638:Fruit / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D005810:Multigene Family; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D018749:RNA, Plant; D004156:Catechol Oxidase