Carbon source-dependent variation of acquired mutagen resistance of Moniliophthora perniciosa: similarities in natural and artificial systems.
The basidiomycete Moniliophthora perniciosa causes Witches' Broom disease in Theobroma cacao. We studied the influence of carbon source on conditioning hyphae to oxidative stress agents (H(2)O(2), paraquat, 4NQO) and to UVC, toward the goal of assessing the ability of this pathogen to avoid plant defenses involving ROS. Cells exhibited increased resistance to H(2)O(2) when shifted from glucose to glycerol and from glycerol to glycerol. When exposed to paraquat, cells grown in fresh medium were always more resistant. Apparently glycerol and/or fresh media, but not old glucose media, up-regulate oxidative stress defenses in this fungus. For the mutagens UVC and 4NQO, whose prime action on DNA is not via ROS, change of carbon source did not elicit a clear change in sensitivity/resistance. These results correlate with expression of fungal genes that protect against ROS and with biochemical changes observed in infected cacao tissues, where glycerol and high amounts of ROS have been detected in green brooms.
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Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus, CEP 45662-000 Brasil, BA, Brazil.
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Cascardo
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Brendel
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Pungartnik
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D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D000363:Agaricales / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D002099:Cacao / Q000382:microbiology; D002244:Carbon / Q000378:metabolism*; D025141:Drug Resistance, Fungal; D005656:Fungal Proteins / Q000235:genetics; D015870:Gene Expression; D005990:Glycerol / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D025301:Hyphae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D009153:Mutagens / Q000494:pharmacology*; D018384:Oxidative Stress; D010269:Paraquat / Q000494:pharmacology; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology; D021381:Protein Transport; D015533:Transcriptional Activation; D014466:Ultraviolet Rays
D005656:Fungal Proteins; D009153:Mutagens; D015112:4-Nitroquinoline-1-oxide; D002244:Carbon; D006861:Hydrogen Peroxide; D005990:Glycerol; D010269:Paraquat