Work

Aspergillus tamarii and A. flavus Differentially Allocate Resources Between Mycelial Growth and Sporulation During Competition on Maize Kernels

Year: 2026

Type: article

Abstract: Understanding the ecology of fungi in Aspergillus section Flavi is necessary to identify factors that contribute to aflatoxin accumulation risk and to improve interventions to reduce contamination. For example, interactions between non-aflatoxigenic and aflatoxigenic Aspergillus species play a key role in determining the aflatoxin-producing potential of crop-associated fungi. The non-aflatoxigenic species A. tamarii is often associated with agricultural soils and occasionally with crops, prompting the question as to whether A. tamarii and aflatoxigenic A. flavus compete on these crops. In this study, interactions between A. tamarii and A. flavus during co-colonization and sporulation on maize kernels were assessed. In co-culture experiments, mycelial and conidial growth were measured for each species using a custom quantitative PCR assay, and aflatoxin was measured via lateral flow. Both A. tamarii and A. flavus exhibited reduced growth under co-culture, confirming that these species compete for shared resources in maize kernels. However, their responses diverged in ways that suggest distinct life history strategies. In competition, there was a significant relationship between mycelial growth and production of conidia for A. tamarii. In contrast, for A. flavus isolates, the mycelial biomass in kernels and conidia production during co-colonization of maize kernels with A tamarii were not correlated. This suggests differences in resource allocation between growth and reproduction between the two species. Additionally, isolate identity influenced competitive outcomes and aflatoxin production, underscoring the importance of genotype-level variation in fungal interactions. Understanding these species-specific interactions provides insight into fungal dynamics on crops and may inform strategies for managing aflatoxin contamination events. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2026.

Source: PhytoFrontiers™

DOI: 10.1094/phytofr-09-25-0094-r

Authors: Allison Q. Byrne, Hillary L. Mehl, Kenneth A. Callicott

Institutions: Agricultural Research Service, United States Department of Agriculture, U.S. Arid Land Agricultural Research Center

Language: English

Topic: Mycotoxins in Agriculture and Food

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: diamond

Funder: Agricultural Research Service