Lipoxygenase Activity Accelerates Programmed Spore Germination in Aspergillus fumigatus
Gregory J Fischer1, William Bacon2, Jun Yang3
1Department of Genetics, University of Wisconsin-Madison, MadisonWI, USA.
Frontiers in Microbiology
|May 25, 2017
Summary
Aspergillus fumigatus uses a lipoxygenase, LoxB, to regulate spore germination. LoxB impacts transitions from spore to germling, especially in environments rich in polyunsaturated fatty acids like arachidonic acid.
Area of Science:
- Mycology
- Molecular Biology
- Pathogen Biology
Background:
- * *Aspergillus fumigatus* is an opportunistic human pathogen.
- * Fungal germination is a critical step for invasive growth.
- * Lipoxygenases play roles in fungal development and metabolism.
Purpose of the Study:
- * To investigate the role of a novel lipoxygenase, LoxB, in *A. fumigatus* spore germination.
- * To understand how LoxB influences the transition from dormant spore to germling.
- * To explore the impact of arachidonic acid and its metabolites on germination.
Main Methods:
- * Gene manipulation (overexpression and deletion) of *loxB* in *A. fumigatus*.
- * Analysis of spore germination stages (swollen spore, germling) under various conditions.
- * Supplementation with arachidonic acid (AA) and 5-hydroxyeicosatetraenoic acid (5-HETE).
Main Results:
- * Overexpression of *loxB* accelerated the progression to the germling stage.
- * Deletion of *loxB* delayed germination to the swollen spore stage, particularly with arachidonic acid.
- * Addition of 5-HETE, a metabolite of AA, rescued the germination delay caused by *loxB* deletion.
Conclusions:
- * *A. fumigatus* LoxB is a key regulator of programmed spore germination.
- * LoxB activity is influenced by polyunsaturated fatty acids and their oxygenated products.
- * The fungal lipoxygenase LoxB may enhance germination in lipid-rich environments, contributing to pathogenicity.
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