Characterisation of the phosphoenolpyruvate carboxylase gene family in sugarcane (Saccharum spp.).
Phosphoenolpyruvate carboxylases (PEPCs) are encoded by a small multigenic family. In order to characterise this gene family in sugarcane, seven DNA fragments displaying a high homology with grass PEPC genes were isolated using polymerase chain reaction-based cloning. A phylogenetic study revealed the existence of four main PEPC gene lineages in grasses and particularly in sugarcane. Moreover, this analysis suggests that grass C4 PEPC has likely derived from a root pre-existing isoform in an ancestral species. Using the Northern-dot-blot method, we studied the expression of the four PEPC gene classes in sugarcane cv. R570. We confirmed that transcript accumulation of the C4 PEPC gene (ppc-C4) mainly occurs in the green leaves and is light-induced. We also showed that another member of this gene family (ppc-aR) is more highly transcribed in the roots. The constitutive expression for a previously characterised gene (ppc-aL2) was confirmed. Lastly, the transcript accumulation of the fourth PEPC gene class (ppc-aL1) was not revealed. Length polymorphism in non-coding regions for three PEPC gene lineages enabled us to develop sequence-tagged site PEPC markers in sugarcane. We analysed the segregation of PEPC fragments in self-pollinated progenies of cv. R570 and found co-segregating fragments for two PEPC gene lineages. This supports the hypothesis that diversification of the PEPC genes involved duplications, probably in tandem.
Besnard
G
G
Université de la Réunion, LBGM, 15 Avenue R. Cassin, 97715 St-Denis Messag 9, La Réunion, France. gbesnar@hotmail.com
Pinçon
G
G
D'Hont
A
A
Hoarau
J-Y
JY
Cadet
F
F
Offmann
B
B
D001483:Base Sequence; D015152:Blotting, Northern; D016000:Cluster Analysis; D017931:DNA Primers; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D009928:Organ Specificity; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics*; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D020133:Reverse Transcriptase Polymerase Chain Reaction; D031786:Saccharum / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D017931:DNA Primers; D010730:Phosphoenolpyruvate Carboxylase