Manuscrito
Genetic variants of the TORC1 signaling pathway affect nitrogen consumption in Saccharomyces cerevisiae during the alcoholic fermentation
Fecha
2018Institución
Resumen
During the alcoholic fermentation, S. cerevisiae strains present differences in their nitrogen
16 consumption profiles, however, the molecular origins of these variations are little understood. In
17 this sense, variations in the nitrogen signaling pathways, which in turn are regulated by the TORC1
18 pathway, represent one of the main sources of phenotypic diversity in nitrogen consumption
19 between strains. Thus, allelic variants from the TORC1 pathway might contribute to the nitrogen
20 consumption differences during the alcoholic fermentation. Here, we studied the allelic diversity in
21 the TORC1 pathway across four strains and determined how these polymorphisms directly impact
22 nitrogen consumption during the alcoholic fermentation. Interestingly, we found that allelic variants
23 of GTR1, TOR2, SIT4, SAP185, EAP1, NPR1 and SCH9 underlie differences in the consumption of
24 ammonium and amino acids. Among these, GTR1 showed the greatest effect ammonium
25 consumption. Furthermore, we identified allelic variants of SAP185, TOR2, SCH9 and NPR1 from
26 an oak isolate having a positive impact on nitrogen consumption (higher amino acid consumption);
27 representing putative candidates from non-domesticated strains for genetic improvement programs.
28 Therefore, we demonstrate that a relatively large number of allelic variants within the TORC1
29 pathway significantly affect regulatory mechanisms of nitrogen assimilation, influencing the
30 nitrogen consumption differences between strains.
31 Keywords: Wine, Saccharomyces cerevisiae, allelic diversity, nitrogen consumption, TORC1
32 pathway, gene expression.