Functional characterization of a plant-like sucrose transporter from the beneficial fungus Trichoderma virens. Regulation of the symbiotic association with plants by sucrose metabolism inside the fungal cells.
• Sucrose exuded by plants into the rhizosphere is a crucial component for the symbiotic association between the beneficial fungus Trichoderma and plant roots. In this article we sought to identify and characterize the molecular basis of sucrose uptake into the fungal cells. • Several bioinformatics tools enabled us to identify a plant-like sucrose transporter in the genome of Trichoderma virens Gv29-8 (TvSut). Gene expression profiles in the fungal cells were analyzed by Northern blotting and quantitative real-time PCR (qRT-PCR). Biochemical and physiological studies were conducted on Gv29-8 and fungal strains impaired in the expression of TvSut. • TvSut exhibits biochemical properties similar to those described for sucrose symporters from plants. The null expression of tvsut caused a detrimental effect on fungal growth when sucrose was the sole source of carbon in the medium, and also affected the expression of genes involved in the symbiotic association. • Similar to plants, T. virens contains a highly specific sucrose/H(+) symporter that is induced in the early stages of root colonization. Our results suggest an active sucrose transference from the plant to the fungal cells during the beneficial associations. In addition, our expression experiments suggest the existence of a sucrose-dependent network in the fungal cells that regulates the symbiotic association.
Department of Plant Pathology and Microbiology Texas A&M University, College Station, TX 77843, USA.|Present address: Centro Hispanoluso de Investigaciones Agrárias (CIALE), Departamento de Microbiologia y Genética, Universidad de Salamanca, 37185 Salamanca, Spain.
Walter A
WA
Vargas
Department of Plant Pathology and Microbiology Texas A&M University, College Station, TX 77843, USA.
Frankie K
FK
Crutcher
Department of Plant Pathology and Microbiology Texas A&M University, College Station, TX 77843, USA.
Charles M
CM
Kenerley
D001692:Biological Transport / Q000235:genetics; D015152:Blotting, Northern; D005656:Fungal Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D038821:Mycorrhizae / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013395:Sucrose / Q000378:metabolism*; D013559:Symbiosis / Q000502:physiology*; D027981:Symporters / Q000378:metabolism; D014242:Trichoderma / Q000166:cytology / Q000235:genetics* / Q000502:physiology; D003313:Zea mays / Q000382:microbiology
D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D010940:Plant Proteins; D027981:Symporters; C078729:sucrose transport protein, plant; D013395:Sucrose