Heat shock, copper sulfate and oxidative stress activate the retrotransposon MAGGY resident in the plant pathogenic fungus Magnaporthe grisea.
MAGGY is a gypsy-like retrotransposon isolated from the plant pathogenic fungus Magnaporthe grisea. The ability of various stresses to activate MAGGY was tested in the original and in a heterologous host (Colletotrichum lagenarium), using beta-glucuronidase (GUS) as a reporter. The MAGGY promoter was activated in M. grisea by either heat shock, copper sulfate, or oxidative stress, but not by the antifungal substance p-coumaric acid. Transcriptional up-regulation of MAGGY RNA was also observed following heat shock and oxidative stress. The MAGGY promoter remained responsive to the above-mentioned stresses when transformed into a M. grisea isolate that had no endogenous MAGGY elements. In C. lagenarium, however, the MAGGY promoter showed only basal expression of GUS and no further up-regulation was induced by any of the stress treatments, suggesting that the stress-responding cis-element(s) in the MAGGY promoter is not functional in a wider range of fungi. The relationship between the activation of MAGGY by stress and phenotypic diversification in M. grisea, including variations in pathogenicity, is discussed.
Ikeda
K
K
Laboratory of Plant Pathology, Faculty of Agriculture, Kobe University, Nada, Japan.
Nakayashiki
H
H
Takagi
M
M
Tosa
Y
Y
Mayama
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D020231:Colletotrichum / Q000235:genetics; D019327:Copper Sulfate / Q000494:pharmacology*; D003373:Coumaric Acids / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D005966:Glucuronidase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018869:Heat-Shock Response; D020082:Magnaporthe / Q000235:genetics*; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics; D018384:Oxidative Stress; D010269:Paraquat / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011422:Propionates; D012313:RNA / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018626:Retroelements / Q000235:genetics*; D014170:Transformation, Genetic; D014908:Triticum / Q000235:genetics
D003373:Coumaric Acids; D011422:Propionates; D011993:Recombinant Fusion Proteins; D018626:Retroelements; D012313:RNA; D005966:Glucuronidase; C495469:p-coumaric acid; D019327:Copper Sulfate; D010269:Paraquat