Publications des scientifiques de l'IRD

Joët Thierry, Laffargue Andréina, Salmona J., Doulbeau Sylvie, Descroix F., Bertrand B., Lashermes Philippe, Dussert Stéphane. (2014). Regulation of galactomannan biosynthesis in coffee seeds. Journal of Experimental Botany, 65 (1), p. 323-337. ISSN 0022-0957.

Titre du document
Regulation of galactomannan biosynthesis in coffee seeds
Année de publication
2014
Type de document
Article référencé dans le Web of Science WOS:000329868000026
Auteurs
Joët Thierry, Laffargue Andréina, Salmona J., Doulbeau Sylvie, Descroix F., Bertrand B., Lashermes Philippe, Dussert Stéphane
Source
Journal of Experimental Botany, 2014, 65 (1), p. 323-337 ISSN 0022-0957
The seed of Coffea arabica accumulates large amounts of cell wall storage polysaccharides (CWSPs) of the mannan family in the cell walls of the endosperm. The variability induced by the growing environment and extensive pairwise correlation analysis with stringent significance thresholds was used to investigate transcripttranscript and transcriptmetabolite relationships among 26 sugar-related genes, and the amount of CWSPs and seven soluble low molecular weight carbohydrates in the developing coffee endosperm. A dense module of nine quantitatively co-expressed genes was detected at the mid-developmental stage when CWSPs accumulate. This module included the five genes of the core galactomannan synthetic machinery, namely genes coding for the enzymes needed to assemble the mannan backbone (mannan synthase, ManS), and genes that introduce the galactosyl side chains (galactosyltransferase, GMGT), modulate the post-depositional degree of galactose substitution (-galactosidase), and produce the nucleotide sugar building blocks GDP-mannose and UDP-galactose (mannose-1P guanyltransferase and UDP-glucose 4-epimerase, respectively). The amount of CWSPs stored in the endosperm at the onset of their accumulation was primarily and quantitatively modulated at the transcriptional level (i.e. positively correlated with the expression level of these key galactomannan biosynthetic genes). This analysis also suggests a role for sorbitol and raffinose family oligosaccharides as transient auxiliary sources of building blocks for galactomannan synthesis. Finally, a microarray-based analysis of the developing seed transcriptome revealed that all genes of the core galactomannan synthesis machinery grouped in a single cluster of 209 co-expressed genes. Analysis of the gene composition of this cluster revealed remarkable functional coherence and identified transcription factors that putatively control galactomannan biosynthesis in coffee.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du monde végétal [076]
Localisation
Fonds IRD [F B010061496]
Identifiant IRD
fdi:010061496
Contact