A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis

• DOI: 10.1371/journal.pbio.1000303
• Publication Date: 2010-02-08T23:02:20Z
• Authors: Ramon Wahl; Kathrin Wippel; Sarah Goos; Jörg Kämper; Norbert Sauer
• Keywords: Ustilago; Virulence factor

Plant pathogenic fungi cause massive yield losses and affect both quality safety of food feed produced from infected plants. The main objective plant is to get access the organic carbon sources their carbon-autotrophic hosts. However, chemical nature source(s) mode uptake are largely unknown. Here, we present a novel, plasma membrane-localized sucrose transporter (Srt1) corn smut fungus Ustilago maydis its characterization as fungal virulence factor. Srt1 has an unusually high substrate affinity, absolutely specific, allows direct utilization at plant/fungal interface without extracellular hydrolysis and, thus, production monosaccharides known elicit immune responses. srt1 expressed exclusively during infection, deletion strongly reduces virulence. This emphasizes central role this protein for efficient supply avoidance apoplastic signals potentially recognized by host.