Variation in intron length in caffeic acid O-methyltransferase (COMT) in Vanilla species (Orchidaceae).
Variation in intron length in caffeic acid O-methyltransferase (COMT) in Vanilla was studied and demonstrated that COMT genes in Vanilla are organized with four exons and three introns. At least two to four different versions (either allelic or paralogous) of the COMT multigenic family in the genus Vanilla (in terms of intron sizes) were detected. The three introns were differentially variable, with intron-1 being the most length-polymorphic. Patterns of variations were in accordance with known phylogenetic relationships in the genus obtained with neutral markers. In particular, the genus displayed a strong Old World versus New World differentiation with American fragrant species being characterized by a specific 99bp intron-1 size-variant and a unique 226bp intron-3 variant. Conversely, leafless species of the genus displayed unexpected variations in intron lengths. Due to their role in primary (lignin) and secondary (phenolics, e.g., vanillin, alkaloids) metabolisms, COMT genes might not be neutral markers, and represent candidate functional markers for resistance, aromatic or medicinal properties of Vanilla species. Investigating the orthologous/paralogous status of the different genes revealed (in terms of intron size) will allow the evolution of the COMT genes to be studied.
Universite de la Reunion, UMR PVBMT "Peuplements végétaux et bioagresseurs en milieu tropical" Universite Reunion-Cirad, 15 avenue Rene Cassin, BP7151, 97715 Saint Denis messag cedex 9, La Reunion, France. Electronic address: besse@univ-reunion.fr.
Pascale
P
Besse
Universite de la Reunion, UMR PVBMT "Peuplements végétaux et bioagresseurs en milieu tropical" Universite Reunion-Cirad, 15 avenue Rene Cassin, BP7151, 97715 Saint Denis messag cedex 9, La Reunion, France.
Denis
D
Da Silva
Universite de la Reunion, UMR PVBMT "Peuplements végétaux et bioagresseurs en milieu tropical" Universite Reunion-Cirad, 15 avenue Rene Cassin, BP7151, 97715 Saint Denis messag cedex 9, La Reunion, France; CIRAD, UMR PVBMT "Peuplements végétaux et bioagresseurs en milieu tropical" Universite Reunion-Cirad, Pôle de Protection des Plantes, 7 chemin de l'IRAT, 97410 Saint Pierre, La Reunion, France.
Séverine
S
Bory
IRD, UMR PVBMT "Peuplements végétaux et bioagresseurs en milieu tropical" Universite Reunion-Cirad, Pôle de Protection des Plantes, 7 chemin de l'IRAT, 97410 Saint Pierre, La Reunion, France.
Michel
M
Noirot
CIRAD, UMR PVBMT "Peuplements végétaux et bioagresseurs en milieu tropical" Universite Reunion-Cirad, Pôle de Protection des Plantes, 7 chemin de l'IRAT, 97410 Saint Pierre, La Reunion, France.
Michel
M
Grisoni
COMT; Diversity; Intron; PCR; Vanilla