Metabolic pathways in tropical dicotyledonous albuminous seeds: Coffea arabica as a case study.
* The genomic era facilitates the understanding of how transcriptional networks are interconnected to program seed development and filling. However, to date, little information is available regarding dicot seeds with a transient perisperm and a persistent, copious endosperm. Coffea arabica is the subject of increasing genomic research and is a model for nonorthodox albuminous dicot seeds of tropical origin. * The aim of this study was to reconstruct the metabolic pathways involved in the biosynthesis of the main coffee seed storage compounds, namely cell wall polysaccharides, triacylglycerols, sucrose, and chlorogenic acids. For this purpose, we integrated transcriptomic and metabolite analyses, combining real-time RT-PCR performed on 137 selected genes (of which 79 were uncharacterized in Coffea) and metabolite profiling. * Our map-drawing approach derived from model plants enabled us to propose a rationale for the peculiar traits of the coffee endosperm, such as its unusual fatty acid composition, remarkable accumulation of chlorogenic acid and cell wall polysaccharides. * Comparison with the developmental features of exalbuminous seeds described in the literature revealed that the two seed types share important regulatory mechanisms for reserve biosynthesis, independent of the origin and ploidy level of the storage tissue.
Joët
Thierry
T
IRD, UMR DIA-PC, Pôle de Protection des Plantes, 97410, Saint Pierre, La Réunion, France.
Laffargue
Andréina
A
IRD, UMR DIA-PC, BP 64501, 34394 Montpellier, France.
Salmona
Jordi
J
IRD, UMR DIA-PC, Pôle de Protection des Plantes, 97410, Saint Pierre, La Réunion, France.
Doulbeau
Sylvie
S
IRD, UMR DIA-PC, BP 64501, 34394 Montpellier, France.
Descroix
Frédéric
F
CIRAD, UMR QualiSud, 97410, Saint Pierre, La Réunion, France.
Bertrand
Benoît
B
CIRAD, UMR RPB, BP 64501, 34394 Montpellier, France.
de Kochko
Alexandre
A
IRD, UMR DIA-PC, BP 64501, 34394 Montpellier, France.
Dussert
Stéphane
S
IRD, UMR DIA-PC, BP 64501, 34394 Montpellier, France.
D000214:Acyl Coenzyme A / Q000096:biosynthesis; D050260:Carbohydrate Metabolism; D002726:Chlorogenic Acid / Q000378:metabolism; D040503:Coffea / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008031:Lignin / Q000378:metabolism; D050356:Lipid Metabolism; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000196:embryology / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D014158:Transcription, Genetic; D014329:Tropical Climate
D000214:Acyl Coenzyme A; D005227:Fatty Acids; D010938:Plant Oils; D012333:RNA, Messenger; D002726:Chlorogenic Acid; D013395:Sucrose; D013213:Starch; D008031:Lignin