TY - JOUR
T1 - Characterization of the Aspergillus parasiticus Δ 12-desaturase gene
T2 - A role for lipid metabolism in the Aspergillus-seed interaction
AU - Wilson, Richard A.
AU - Calvo, Ana M.
AU - Chang, Perng Kuang
AU - Keller, Nancy P.
PY - 2004/9
Y1 - 2004/9
N2 - In the mycotoxigenic oilseed pathogens Aspergillus flavus and Aspergillus parasiticus and the model filamentous fungus Aspergillus nidulans, unsaturated fatty acids and their derivatives act as important developmental signals that affect asexual conidiospore, sexual ascospore and/or sclerotial development. To dissect the relationship between lipid metabolism and fungal development, an A. parasiticus Δ 12-desaturase mutant that was unable to convert oleic acid to linoleic acid and was thus impaired in polyunsaturated fatty acid biosynthesis was generated. The Δ12-desaturase mutant demonstrates delayed spore germination, a twofold reduction in growth, a reduced level of conidiation and complete loss of sclerotial development, compared to the wild-type. Host colonization is impaired, as reflected by a decrease in conidial production on live peanut and corn seed by the mutant compared to the wild-type. Similarly, the previously isolated A. nidulans Δ12-desaturase mutant has reduced colonization capabilities compared to the wild-type. Therefore, desaturation mutants display a key requisite that affords a genetic solution to oilseed crop contamination by mycotoxigenic Aspergillus species: a reduction in the production of conidia, the infectious particle of the pathogenic aspergilli.
AB - In the mycotoxigenic oilseed pathogens Aspergillus flavus and Aspergillus parasiticus and the model filamentous fungus Aspergillus nidulans, unsaturated fatty acids and their derivatives act as important developmental signals that affect asexual conidiospore, sexual ascospore and/or sclerotial development. To dissect the relationship between lipid metabolism and fungal development, an A. parasiticus Δ 12-desaturase mutant that was unable to convert oleic acid to linoleic acid and was thus impaired in polyunsaturated fatty acid biosynthesis was generated. The Δ12-desaturase mutant demonstrates delayed spore germination, a twofold reduction in growth, a reduced level of conidiation and complete loss of sclerotial development, compared to the wild-type. Host colonization is impaired, as reflected by a decrease in conidial production on live peanut and corn seed by the mutant compared to the wild-type. Similarly, the previously isolated A. nidulans Δ12-desaturase mutant has reduced colonization capabilities compared to the wild-type. Therefore, desaturation mutants display a key requisite that affords a genetic solution to oilseed crop contamination by mycotoxigenic Aspergillus species: a reduction in the production of conidia, the infectious particle of the pathogenic aspergilli.
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U2 - 10.1099/mic.0.27207-0
DO - 10.1099/mic.0.27207-0
M3 - Article
C2 - 15347747
AN - SCOPUS:4844228962
SN - 1350-0872
VL - 150
SP - 2881
EP - 2888
JO - Microbiology
JF - Microbiology
IS - 9
ER -