Overexpression of MET4 Leads to the Upregulation of Stress-Related Genes and Enhanced Sulfite Tolerance in Saccharomyces uvarum

Abstract

Saccharomyces uvarum is one of the few fermentative species that can be used in winemaking, but its weak sulfite tolerance is the main reason for its further use. Previous studies have shown that the expression of the methionine synthase gene (MET4) is upregulated in FZF1 (a gene encoding a putative zinc finger protein, which is a positive regulator of the transcription of the cytosolic sulfotransferase gene SSU1) overexpression transformant strains, but its exact function is unknown. To gain insight into the function of the MET4 gene, in this study, a MET4 overexpression vector was constructed and transformed into S. uvarum strain A9. The MET4 transformants showed a 20 mM increase in sulfite tolerance compared to the starting strain. Ninety-two differential genes were found in the transcriptome of A9-MET4 compared to the A9 strain, of which 90 were upregulated, and two were downregulated. The results of RT-qPCR analyses confirmed that the expression of the HOMoserine requiring gene (HOM3) in the sulfate assimilation pathway and some fermentation-stress-related genes were upregulated in the transformants. The overexpression of the MET4 gene resulted in a significant increase in sulfite tolerance, the upregulation of fermentation-stress-related gene expression, and significant changes in the transcriptome profile of the S. uvarum strain.

Transcriptome Analysis of Low-Temperature-Treated Tetraploid Yellow Actinidia chinensis Planch. Tissue Culture Plantlets

“…The 2 (− ΔΔCt) method [ 21 ] was employed to analyze the data. We calculated the correlation coefficient and difference significances using Microsoft Excel 2007 (Microsoft Corporation, Redmond, WA, USA) [ 27 ].…”

The Isolation of Anaerobic and Facultative Anaerobic Sulfate-Reducing Bacteria (SRB) and a Comparison of Related Enzymes in Their Sulfate Reduction Pathways

“…Information on enzymes related to the sulfate reduction pathway can be found on the KEGG website (http://www.kegg.jp/, accessed on 26 April 2023), and the amino acid sequences encoding the target enzymes, i.e., the genetic codes for these enzymes, can be found in the proteomes of the downloaded standard type strains. However, previous studies have focused separately on the Dsr of the dissimilatory sulfate reduction pathway [28], as well as the enzymes in the assimilation pathway, such as sulfite reductase (NADPH) [29], but have rarely reported the similarities and differences in the distribution between the related enzymes in the sulfate reduction pathway of anaerobic SRB and facultative anaerobic SRB.…”