Trehalose is required for stress resistance and virulence of the Basidiomycota plant pathogen Ustilago maydis

Abstract

Trehalose is an important disaccharide that can be found in bacteria, fungi, invertebrates and plants. In some Ascomycota fungal plant pathogens, the role of trehalose was recently studied and shown to be important for conferring protection against several environmental stresses and for virulence. In most of the fungi studied, two enzymes are involved in the synthesis of trehalose: trehalose-6-phosphate synthase (Tps1) and trehalose-6-phosphate phosphatase (Tps2). To study the role of trehalose in virulence and stress response in the Basidiomycota maize pathogen Ustilago maydis, Δtps2 deletion mutants were constructed. These mutants did not produce trehalose as confirmed by HPLC analysis, showing that the single gene disruption impaired its biosynthesis. The mutants displayed increased sensitivity to oxidative, heat, acid, ionic and osmotic stresses as compared to the wild-type strains. Virulence of Δtps2 mutants to maize plants was extremely reduced compared to wild-type strains, possibly due to reduced capability to deal with the hostile host environment. The phenotypic traits displayed by Δtps2 strains were fully restored to wild-type levels when complemented with the endogenous UmTPS2 gene, or a chimeric construct having the Saccharomyces cerevisiae TPS2 ORF. This report demonstrates the presence of a single biosynthetic pathway for trehalose, and its importance for virulence in this model Basidiomycota plant pathogen.

An Optimized Ustilago maydis for Itaconic Acid Production at Maximal Theoretical Yield

“…The trehalase activity in these cells was increased at the same time, indicating cellular mechanisms for a rapid adaption of the trehalose content. Cervantes-Chávez et al [60] found that U. maydis mutants with a disrupted trehalose biosynthesis pathway were more sensitive to osmotic stress than the wildtype. Assuming that the itaconate produced and the 0.5-1 M glucose pulses had a similar effect, it is reasonable to assume that the U. maydis cells were stressed during the pulsed fed-batch fermentations.…”

Host factors that promote retrotransposon integration are similar in distantly related eukaryotes

“…They are mostly unrelated making it difficult to identify a specific pathway that might mediate integration. The exception is that the metabolic factors included both enzymes responsible for synthesis of trehalose, a disaccharide that mitigates the impact of heat and oxidative stress [ 64 – 66 ]. What is more intriguing is that one of these enzymes trehalose-phosphate synthase (Tps2) is important for Ty1 transposition [ 22 ].…”

Functional validation of pathogenicity genes in rice sheath blight pathogen Rhizoctonia solani by a novel host‐induced gene silencing system

“…Trehalose is an essential disaccharide for the survival and virulence of pathogenic fungi and plays roles during conidiogenesis, spore germination, and sexual development (Botts et al, 2014 ; Cervantes‐Chavez et al, 2016 ; Foster et al, 2003 ; Li et al, 2009 ; Puttikamonkul et al, 2010 ; Song et al, 2014 ). Trehalose protects the cells by preventing protein denaturation and scavenging ROS (Cao et al, 2008 ; Crowe, 2007 ).…”

“…Nevertheless, a Tps2 mutant in U . maydis resulted in a lack of trehalose production with extremely reduced virulence to maize (Cervantes‐Chavez et al, 2016 ). Deficiency of Tps2 in F .…”