Monitoring the transcriptome and the proteome of the wine yeast EC1118 during alcoholic fermentation.
Tristan Rossignol (1), Dominique kobi (2), Laurence Gutfreund (2), Bruno Blondin (1)
(1) Microbiology, UMR SPO INRA-Agrgo.M, 1, place Viala, Montpellier, 34060, Montpellier, France; (2) Tepral Kronenbourg, 68, Route d'Oberhausbergen, 67037 Strasbourg
The transcriptome and the proteome of the wine yeast EC1118 were monitored during alcoholic fermentation by microarrays and 2D-gel electrophoresis respectively. Transcriptome analyses revealed strong changes in mRNA abundance during fermentation and about 2000 genes were more than 3-fold regulated between growth and stationary phase. Entry into the stationary phase triggered major transcriptional reprogramming, a relief from nitrogen repression and a general stress response. The proteome samples characterized indicated that the overall protein abundance was correlated with the mRNA abundance. However changes in protein abundance during fermentation were much weaker than that of mRNA and there was no general correlation between change in mRNA abundance with that of the corresponding protein. Correlation appeared to be highly dependent on protein cellular role, those involved in protein synthesis displaying a good correlation, while proteins involved in amino acid biosynthesis and stress response were poorly correlated with the mRNA changes. Conversely, various glycolytic enzymes increased during the stationary phase while their mRNA decreased. As a whole our data suggest that the proteome is much more buffered than the transcriptome during alcoholic fermentation and that post-transcriptional control play an important role in the overall regulatory processes.