Related Experiment Video
Updated: Jul 10, 2026
09:21
Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L.
Published on: February 15, 2019
Aspergillus flavus hydrolases: their roles in pathogenesis and substrate utilization
Jay E Mellon1, Peter J Cotty, Michael K Dowd
1US Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, P. O. Box 19687, New Orleans, LA 70179, USA. jmellon@srrc.ars.usda.gov
Applied Microbiology and Biotechnology
|October 17, 2007
Summary
Aspergillus flavus produces extracellular hydrolases for nutrient acquisition and host invasion. Understanding hydrolase regulation is key to controlling aflatoxin contamination in crops.
Area of Science:
- Mycology
- Plant Pathology
- Biochemistry
Background:
- Aspergillus flavus is an opportunistic fungal pathogen impacting agriculture.
- It produces aflatoxins, a carcinogen that reduces crop value.
- Extracellular hydrolases aid nutrient acquisition and host tissue penetration.
Purpose of the Study:
- To investigate the role and regulation of extracellular hydrolases in Aspergillus flavus.
- To understand how hydrolases contribute to fungal virulence and aflatoxin production.
Main Methods:
- Focus on serine and metalloproteinases, pectinase P2c, and amylase.
- Analysis of hydrolase secretion regulation and substrate dependence.
- Correlation of hydrolase secretion with fungal virulence and aflatoxin biosynthesis.
Main Results:
- Hydrolases are crucial for polymer degradation and nutrient capture.
- Proteinases contribute to accessing protein substrates and may enhance virulence.
- Endopolygalacturonase P2c secretion correlates with plant virulence.
- Alpha-amylase is vital for starch digestion and aflatoxin induction in some hosts.
Conclusions:
- Hydrolase production and utilization by A. flavus are complex and substrate-dependent.
- Further research into hydrolase function is critical for managing aflatoxin contamination.
- Targeting hydrolase activity may offer novel strategies for crop protection.
Related Concept Videos
01:29Fungal Group Zygomycota
Zygomycota, previously classified as a distinct fungal group, are primarily terrestrial, saprophytic molds that play a crucial role as decomposers. Recent phylogenetic studies have revealed that these fungi are now divided into two major clades — Mucoromycota, which includes many symbiotic species, and Zoopagomycota, which primarily consists of parasitic and pathogenic fungi. These groups exhibit distinct ecological roles and reproductive strategies while sharing key structural and...
01:15Antifungal Agents
Amphotericin B is a broad-spectrum antifungal agent that exploits structural differences between fungal and mammalian cell membranes. Its amphipathic structure—featuring a hydrophobic polyene-lactone ring and a hydrophilic region containing mycosamine and carboxylic acid groups—enables selective binding to ergosterol, a sterol predominantly found in fungal plasma membranes. This selective interaction underlies the drug’s antifungal activity, although weak binding to cholesterol contributes to...
01:28Fungal Phylum Ascomycota
Phylum Ascomycota, a major division within the subkingdom Dikarya, comprises a diverse range of fungal species, including both unicellular yeasts and filamentous molds such as Aspergillus and Penicillium. These fungi thrive in a variety of habitats, from aquatic ecosystems to terrestrial environments, playing crucial ecological and economic roles.Morphology and ReproductionThe defining characteristic of Ascomycetes, commonly referred to as sac fungi, is the ascus—a sac-like structure that...
01:29Overview of Fungi
Fungi are a diverse group of eukaryotes more closely related to animals than other eukaryotes. Fungal cell walls comprise chitin, a polysaccharide that provides structural strength, and glucans, which contribute to flexibility and integrity. Other polysaccharides, such as mannans and galactosans, may supplement or replace chitin in some fungi. These adaptations, along with their preference for acidic environments and tolerance for high osmotic pressure, enable fungi to thrive in various...
01:28Gene Regulation in Microbial Communities: Quorum Sensing
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
01:26Fungal Phylum Basidiomycota
Basidiomycota is a diverse phylum of fungi that includes ecologically significant decomposers such as white rot fungi, symbionts like mycorrhizal fungi, plant pathogens such as rusts and smuts, and edible species like Agaricus bisporus (the common button mushroom). These fungi play crucial roles in nutrient cycling, symbiotic relationships, and even human health. Their defining feature is the basidium, a microscopic club-shaped structure responsible for producing basidiospores.Fruiting Bodies...