a novel high-affinity sucrose transporter is required for virulence of the plant pathogen ustilago maydis需要一种新颖的高亲和性蔗糖转运蛋白毒性的植物病原体黑粉菌属maydis.pdfVIP

A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis 1,2.¤ 3. 1 ¨ ¨ 1,2¤ 3 Ramon Wahl , Kathrin Wippel , Sarah Goos , Jorg Kamper *, Norbert Sauer * 1 Karlsruhe Institute of Technology, Institute for Applied Biosciences, Department of Genetics, Karlsruhe, Germany, 2 Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany, 3 Friedrich-Alexander-University Erlangen-Nuremberg, Molecular Plant Physiology, Erlangen, Germany Abstract Plant pathogenic fungi cause massive yield losses and affect both quality and safety of food and feed produced from infected plants. The main objective of plant pathogenic fungi is to get access to the organic carbon sources of their carbon- autotrophic hosts. However, the chemical nature of the carbon source(s) and the mode of uptake are largely unknown. Here, we present a novel, plasma membrane-localized sucrose transporter (Srt1) from the corn smut fungus Ustilago maydis and its characterization as a fungal virulence factor. Srt1 has an unusually high substrate affinity, is absolutely sucrose specific, and allows the direct utilization of sucrose at the plant/fungal interface without extracellular hydrolysis and, thus, without the production of extracellular monosaccharides known to elicit plant immune responses. srt1 is expressed exclusively during infection, and its deletion strongly reduces fungal virulence. This emphasizes the central role of this protein both for efficient carbon supply and for avoidance of apoplastic signals potentially recognized by the host. ¨ Citation: Wahl R, Wippel K,