Use of chemosensitization to overcome fludioxonil resistance in Penicillium expansum.
OBJECTIVE
To overcome fludioxonil resistance of Penicillium expansum, a mycotoxigenic fungal pathogen causing postharvest decay in apple, by using natural phenolic chemosensitizing agents.


RESULTS
Fludioxonil-resistant mutants of P. expansum were co-treated with different oxidising and natural phenolic agents. Resistance was overcome by natural phenolic chemosensitizing agents targeting the oxidative stress-response pathway. These agents also augmented effectiveness of the fungicide, kresoxim-methyl. Results indicated that alkyl gallates target mitochondrial respiration and/or its antioxidation system. Fungal mitochondrial superoxide dismutase (Mn-SOD) plays a protective role against alkyl gallates.


CONCLUSIONS
Natural chemosensitizing agents targeting the oxidative stress-response system, such as Mn-SOD, can synergize commercial fungicides.


CONCLUSIONS
Redox-active compounds can serve as potent chemosensitizing agents to overcome resistance and lower effective dosages of fungicides. This can reduce costs with coincidental lowering of environmental and health risks.
Plant Mycotoxin Research Unit, Western Regional Research Center, USDA-ARS, Albany, CA, USA.
J H
JH
Kim
B C
BC
Campbell
N
N
Mahoney
K L
KL
Chan
R J
RJ
Molyneux
C L
CL
Xiao
D000935:Antifungal Agents / Q000494:pharmacology*; D004149:Dioxoles / Q000494:pharmacology*; D004347:Drug Interactions; D025141:Drug Resistance, Fungal / Q000187:drug effects*; D005656:Fungal Proteins / Q000378:metabolism; D027845:Malus / Q000382:microbiology; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D008689:Methacrylates / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects; D024101:Mitochondrial Proteins / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D010407:Penicillium / Q000187:drug effects* / Q000302:isolation & purification; D010636:Phenols / Q000494:pharmacology*; D010648:Phenylacetates / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology*; D000073739:Strobilurins; D013482:Superoxide Dismutase / Q000378:metabolism
D000935:Antifungal Agents; D004149:Dioxoles; D005656:Fungal Proteins; D008689:Methacrylates; D024101:Mitochondrial Proteins; D016877:Oxidants; D010636:Phenols; D010648:Phenylacetates; D011758:Pyrroles; D000073739:Strobilurins; C469328:kresoxim-methyl; D013482:Superoxide Dismutase; C108339:fludioxonil