A putative amino acid transporter is specifically expressed in haustoria of the rust fungus Uromyces fabae.
A cDNA library constructed from haustoria of the rust fungus Uromyces fabae was screened for clones that are differentially expressed in haustoria. One family of cDNAs (in planta-induced gene 2 [PIG2] was isolated and found to encode a protein with high homologies to fungal amino acid transporters. A cDNA clone containing the complete coding region of PIG2 and the corresponding genomic clone were isolated and sequenced, revealing the presence of 17 introns in the PIG2 gene. Expression of PIG2 mRNA appeared to be restricted to haustoria. With antibodies raised against synthetic peptides, the PIG2-encoded protein was found in membranes fractions of isolated haustoria but not of germinated rust spores. With immunofluorescence microscopy, the putative amino acid transporter was localized to plasma membranes of the haustorial bodies, but not detected in the haustorial neck, haustorial mother cells, or intercellular fungal hyphae growing within infected leaf tissue. These data present for the first time molecular evidence that the rust haustorium plays a special role in the uptake of nutrients from an infected host cell.
Hahn
M
M
Fakultät für Biologie, Universität Konstanz, Germany.
Neef
U
U
Struck
C
C
Göttfert
M
M
Mendgen
K
K
D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems; D000596:Amino Acids / Q000378:metabolism*; D001487:Basidiomycota / Q000235:genetics* / Q000378:metabolism; D001692:Biological Transport; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D002451:Cell Compartmentation; D007887:Fabaceae / Q000382:microbiology; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins; D015870:Gene Expression; D005800:Genes, Fungal; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D010946:Plants, Medicinal; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D017386:Sequence Homology, Amino Acid
D026905:Amino Acid Transport Systems; D000596:Amino Acids; D002352:Carrier Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; C106314:PIG2 protein, Uromyces; D012331:RNA, Fungal; D012333:RNA, Messenger