Hxt1, a monosaccharide transporter and sensor required for virulence of the maize pathogen Ustilago maydis. Issue 3 (10th February 2015)

• Record Type: Journal Article
• Authors: Schuler, David; Wahl, Ramon; Wippel, Kathrin; Vranes, Miroslav; Münsterkötter, Martin; Sauer, Norbert; Kämper, Jörg
• Is Part Of: New phytologist. Volume 206:Issue 3(2015)
• Page Start: 1086
• Page End: 1100
• Publication Date: 2015-02-10
• Subjects: biotrophic development -- monosaccharide sensor -- monosaccharide transport -- plant pathogen -- transceptor -- Ustilago maydis; Botany -- Periodicals; 580
• DOI: 10.1111/nph.13314
• Languages: English
• ISSNs: 0028-646X

Abstract

Summary: The smut Ustilago maydis, a ubiquitous pest of corn, is highly adapted to its host to parasitize on its organic carbon sources. We have identified a hexose transporter, Hxt1, as important for fungal development during both the saprophytic and the pathogenic stage of the fungus. Hxt1 was characterized as a high‐affinity transporter for glucose, fructose, and mannose; ∆hxt1 strains show significantly reduced growth on these substrates, setting Hxt1 as the main hexose transporter during saprophytic growth. After plant infection, ∆hxt1 strains show decreased symptom development. However, expression of a Hxt1 protein with a mutation leading to constitutively active signaling in the yeast glucose sensors Snf3p and Rgt2p results in completely apathogenic strains. Fungal development is stalled immediately after plant penetration, implying a dual function of Hxt1 as transporter and sensor. As glucose sensors are only known for yeasts, 'transceptor' as Hxt1 may constitute a general mechanism for sensing of glucose in fungi. In U. maydis, Hxt1 links a nutrient‐dependent environmental signal to the developmental program during pathogenic development. Abstract : See also the Commentary by Jan Schirawski