Accumulation of trehalose by overexpression of tps1, coding for trehalose-6-phosphate synthase, causes increased resistance to multiple stresses in the fission yeast Schizosaccharomyces pombe

Recent studies have shown that heat shock proteins and trehalose synthesis are important factors in the thermotolerance of the fission yeast Schizosac charomyces pombe. We examined the effects of trehalose-6-phosphate (trehalo se-6P) synthase overexpression on resistance to several stresses in cells o f S. pombe transformed with a plasmid bearing the tps1 gene, which codes fo r trehalose-6P synthase, under the control of the strong thiamine-repressib le promoter. Upon induction of trehalose-6P synthase, the elevated levels o f intracellular trehalose correlated not only with increased tolerance to h eat shock but also with resistance to freezing and thawing, dehydration, os mostress, and toxic levels of ethanol, indicating that trehalose may be the stress metabolite underlying the overlap in induced tolerance to these str esses. Among the isogenic strains transformed with this construct, one in w hich the gene coding for the trehalose-hydrolyzing enzyme, neutral trehalas e, was disrupted accumulated trehalose to a greater extent and was more res istant to the above stresses. Increased trehalose concentration is thus a m ajor determinant of the general stress protection response in S. pombe.