Oxidative Stress Tolerance, Adenylate Cyclase and Autophagy Are Key Players in 1 Yeast Chronological Life Span during Winemaking 2 3 4

Running title: CYR1 and RDL2 play a role in wine yeast life span 20 21 Abstract 26 Most grape juice fermentation takes place when yeast cells are in a non dividing state, 27 called the stationary phase. In such circumstances, we aimed to identify the genetic 28 determinants controlling longevity, known as chronological life span. We identified 29 commercial strains with both short (EC1118) and long (CSM) life spans in laboratory 30 growth medium, and compared them under diverse conditions. Strain CSM shows better 31 tolerance to stresses, including oxidative stress, in the stationary phase. This is reflected 32 during winemaking, when this strain has an increased maximum life span. Compared to 33 EC1118, CSM overexpresses a mitochondrial rhodanese-like gene, RDL2, whose 34 deletion leads to increased ROS production at the end of fermentation, and a correlative 35 loss of viability at this point. EC1118 shows faster growth and a higher expression of 36 glycolytic genes, and this is related to greater PKA activity due to the up-regulation of 37 the adenylate cyclase gene. This phenotype has been linked to the presence of a δ 38 element on its promoter, whose removal increases life span. Finally, EC1118 exhibits a 39 higher level of protein degradation by autophagy, which might help achieve fast growth 40 at the expense of cellular structures and may be relevant for long-term survival under 41 winemaking conditions.