VpAAT1, a gene encoding an alcohol acyltransferase, is involved in ester biosynthesis during ripening of mountain papaya fruit.
Mountain papaya ( Vasconcellea pubescens ) is a climacteric fruit that develops a strong and characteristic aroma during ripening. Esters are the main volatile compounds produced by the fruit, and most of them are dependent on ethylene. As esters are synthesized through alcohol acyltransferases (AAT), a full-length cDNA (VpAAT1) was isolated that displayed the characteristic motifs of most plant acyltransferases. The full-length cDNA sequence was cloned and expressed in yeasts, obtaining a functional enzyme with high AAT activity toward the formation of benzyl acetate. The transcript accumulation pattern provided by qPCR analysis showed that the VpAAT1 gene is expressed exclusively in fruit tissues and that a high level of transcripts is accumulated during ripening. The increase in VpAAT1 transcripts in fruit is coincident with the increase in AAT activity; transcript accumulation is induced by ethylene, and it is avoided by 1-methylcyclopropene (1-MCP) treatment. The data indicate that VpAAT1 is involved in aroma formation and that ethylene plays a major role in regulating its expression.
Balbontín
Cristian
C
Laboratorio de Fisiologia Vegetal y Genetica Molecular, Instituto de Biologia Vegetal y Biotecnologia, Universidad de Talca, Casilla 747, Talca, Chile.
Gaete-Eastman
Carlos
C
Fuentes
Lida
L
Figueroa
Carlos R
CR
Herrera
Raúl
R
Manriquez
Daniel
D
Latché
Alain
A
Pech
Jean-Claude
JC
Moya-León
María Alejandra
MA
D000595:Amino Acid Sequence; D029441:Carica / Q000378:metabolism* / Q000502:physiology; D004952:Esters; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D004952:Esters; D011506:Proteins; C079238:alcohol O-acetyltransferase