title: A genetic approach of wine yeast fermentation capacity in nitrogen-starvation reveals the key role of nitrogen signaling.
abstract: BACKGROUND
  In conditions of nitrogen limitation, Saccharomyces cerevisiae strains differ in their fermentation capacities, due to differences in their nitrogen requirements. The mechanisms ensuring the maintenance of glycolytic flux in these conditions are unknown. We investigated the genetic basis of these differences, by studying quantitative trait loci (QTL) in a population of 133 individuals from the F2 segregant population generated from a cross between two strains with different nitrogen requirements for efficient fermentation.
  
  
  RESULTS
  By comparing two bulks of segregants with low and high nitrogen requirements, we detected four regions making a quantitative contribution to these traits. We identified four polymorphic genes, in three of these four regions, for which involvement in the phenotype was validated by hemizygote comparison. The functions of the four validated genes, GCN1, MDS3, ARG81 and BIO3, relate to key roles in nitrogen metabolism and signaling, helping to maintain fermentation performance.
  
  
  CONCLUSIONS
  This study reveals that differences in nitrogen requirement between yeast strains results from a complex allelic combination. The identification of three genes involved in sensing and signaling nitrogen and specially one from the TOR pathway as affecting nitrogen requirements suggests a role for this pathway in regulating the fermentation rate in starvation through unknown mechanisms linking nitrogen signaling to glycolytic flux.
authors.forename: Claire
authors.initials: C
authors.lastname: Brice
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sanchez
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bigey
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Legras
authors.affiliation: INRA, UMR1083 Science pour l'Œnologie, 2 Place Viala, F-34060 Montpellier, France. blondin@supagro.inra.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Blondin
mesh_terms: D005285:Fermentation; D020869:Gene Expression Profiling; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D010445:Peptide Elongation Factors / Q000235:genetics; D010641:Phenotype; D040641:Quantitative Trait Loci; D012097:Repressor Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013312:Stress, Physiological; D000637:Transaminases / Q000235:genetics*; D014920:Wine
chemical_list: C067875:ARG81 protein, S cerevisiae; C501389:GCN1 protein, S cerevisiae; C110020:MDS3 protein, S cerevisiae; D010445:Peptide Elongation Factors; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000637:Transaminases; C000594864:BIO3 protein, S cerevisiae; D009584:Nitrogen