Dongdong Xie, Xing Li, Jiaxin Zheng
During the freeze-thaw cycles, yeast cell integrity is disrupted, and yeast suffers reduced metabolic capacity and weakened fermentation, resulting in the deterioration of dough quality. This study was carried out to explore how the cellular calcium signaling pathway regulates yeast cell response to freeze-thaw cycle stress during different production of frozen dough. The results showed that intracellular calcium content increased significantly under freeze-stress, while calcium content in mitochondria decreased. When yeast cells faced freezing and freeze-thaw stress, the Ca 2+ -ATPase activity of the cell and mitochondrial membrane was decreased. MID1 and CCH1(calcium signal generation), YVC1, PMC1, and VCX1 (regulation of intracellular calcium signal) , CMD1, and CRZ1(intracellular calcium transduction) expression were higher in the freezing and freeze-thaw group than in the control . With the increase of the freeze-thaw cycle, AQY1 (regulation of cell water channel) , CSG2 (encodes endoplasmic reticulum calcium channels) , and MNR2 (encodes Mg2+ transporter protein in the vacuole) expressions were increased significantly; AKR1 , PHO86 (regulation of amino acid metabolism) , VPS27 and PEP3 (protein sorting) , and SGF29 genes (transcriptional regulatory) were up-regulated. During freeze-thaw cycles, calcium signaling responds to stress by regulating the gene expressions related to ionic homeostasis, metabolism, protein sorting, and transcription. This study pioneers a comprehensive calcium signaling map of yeast under freeze-thaw stress in a dough-relevant environment, bridging laboratory findings with industrial applications by identifying specific calcium-regulated genes as molecular targets for enhancing yeast freeze-thaw tolerance and providing actionable strategies for manufacturers to optimize yeast vitality through calcium signaling modulation, thereby improving product quality and production efficiency.