Genetic variants of TORC1 signaling pathway affect nitrogen consumption in Saccharomyces cerevisiae during alcoholic fermentation

PLoS One. 2019 Jul 26;14(7):e0220515. doi: 10.1371/journal.pone.0220515. eCollection 2019.

Abstract

In the alcoholic fermentation process, Saccharomyces cerevisiae strains present differences in their nitrogen consumption profiles, these phenotypic outcomes have complex genetic and molecular architectures. In this sense, variations in nitrogen signaling pathways regulated by TORC1 represent one of the main sources of phenotypic diversity in nitrogen consumption. This emphasizes the possible roles that allelic variants from the TORC1 pathway have in the nitrogen consumption differences observed in yeast during the alcoholic fermentation. Here, we studied the allelic diversity in the TORC1 pathway across four yeast strains and determined how these polymorphisms directly impact nitrogen consumption during alcoholic fermentation. Using a reciprocal hemizygosity approach combined with phenotyping under fermentative conditions, we found that allelic variants of GTR1, TOR2, SIT4, SAP185, EAP1, NPR1 and SCH9 underlie differences in the ammonium and amino acids consumption phenotypes. Among these, GTR1 alleles from the Wine/European and West African genetic backgrounds showed the greatest effects on ammonium and amino acid consumption, respectively. Furthermore, we identified allelic variants of SAP185, TOR2, SCH9 and NPR1 from an oak isolate that increased the amino acid consumption preference over ammonium; representing putative candidates coming from a non-domesticated strain that could be used for genetic improvement programs. In conclusion, our results demonstrated that a large number of allelic variants within the TORC1 pathway significantly impacts on regulatory mechanisms of nitrogen assimilation during alcoholic fermentation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohols / metabolism*
  • Ammonium Compounds / metabolism*
  • Fermentation
  • Genetic Variation*
  • Nitrogen / metabolism*
  • Phenotype
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Signal Transduction
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • Alcohols
  • Ammonium Compounds
  • Saccharomyces cerevisiae Proteins
  • TORC1 protein complex, S cerevisiae
  • Transcription Factors
  • Nitrogen

Grants and funding

This work was supported by the Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) Programa Formación de Capital Humano Avanzado (PCHA) Doctorado Nacional [grant 2014-21140935 to J.M.], Programa de Cooperación Científica ECOS/CONICYT [grant C13B02 to F.A.C., C.M. and G.L.], Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) [grant 1150522 to C.M. and 11170158 to F.S.] and Programa de Cooperación Internacional (CONICYT/PCI) [grant REDI170239 to F.S., G.L. and C.M.]; “Dirección de Investigación Científica y Tecnológica” (DICYT) of the “Universidad de Santiago de Chile” (USACH) grant 081571MF2_POSTDOC to C.M.