QTL mapping reveals novel genes and mechanisms underlying variations in H2S production during alcoholic fermentation in Saccharomyces cerevisiae

Saccharomyces cerevisiae’s requirement of reduced sulfur to synthesise methionine and cysteine during alcoholic fermentation, is mainly fulfilled through the sulfur assimilation pathway. S. cerevisiae reduces sulfate into sulfur dioxide (SO2) and sulfide (H2S), whose overproduction is a major issue in winemaking, due to its negative impact on wine aroma. The amount of H2S produced is highly strain-specific and depends as well on the SO2 concentration, often added to the grape must. Applying a Bulk Segregant Analysis to a 96 strain-progeny derived from two strains with different ability to produce H2S, and comparing the allelic frequencies along the genome of pools of segregants producing opposite H2S quantities, we identified two causative regions involved in H2S production in the presence of SO2. A functional genetic analysis allowed the identification of variants in four genes: ZWF1, ZRT2, SNR2 and YLR125W, able to impact H2S formation, involved in functions and pathways until now not associated with sulfur metabolism. This data points that redox status and zinc homeostasis are linked to H2S formation in wine fermentation conditions and provides new insights into the regulation of H2S production during wine fermentation, giving a new vision of the interplay between the sulfur assimilation pathway and cell metabolism. This archive contains the transcriptome data of the result of allelic swp for three genes : ZWF1, ZRT2, YLR125w under fermentation. For each gene , we analyzed the transcriptome of the two parental strain (WT) , and the transcripttome of the mutant strain obtained after the replacement by the allele of the other parent. Each modality has been analylazed in triplicated.