Publications des agents du Cirad


Characterisation of the phosphoenolpyruvate carboxylase gene family in sugarcane (Saccharum spp.)

Besnard G., Pinçon G., D'Hont A., Hoarau J.Y., Cadet F., Offmann B.G.. 2003. Theoretical and Applied Genetics, 107 (3) : p. 470-478.

DOI: 10.1007/s00122-003-1268-2

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.

Mots-clés : saccharum; phosphoenolpyruvate carboxylase; photosynthèse; pool de gènes; identification; technique analytique

Article (a-revue à facteur d'impact)

Agents Cirad, auteurs de cette publication :