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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #408316
Research Project: Aflatoxin Control through Identification of Intrinsic and Extrinsic Factors Governing the Aspergillus Flavus-Corn Interaction

Location: Food and Feed Safety Research

Title: Microbiota of maize kernels as influenced by Aspergillus flavus infection in susceptible and resistant inbreds

Author
item Moore, Geromy
item CHALIVENDRA, SUBBAIAH - Louisana State University
item Mack, Brian
item Gilbert, Matthew
item Cary, Jeffrey
item Rajasekaran, Kanniah - Rajah

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2023
Publication Date: 11/6/2023
Citation: Moore, G.G., Chalivendra, S., Mack, B.M., Gilbert, M.K., Cary, J.W., Rajasekaran, K. 2023. Microbiota of maize kernels as influenced by Aspergillus flavus infection in susceptible and resistant inbreds. Frontiers in Microbiology. 14:1291284. https://doi.org/10.3389/fmicb.2023.1291284.
DOI: https://doi.org/10.3389/fmicb.2023.1291284

Interpretive Summary: Nearly everything on Earth harbors a microbiome. A microbiome is a community of bacteria, fungi, and viruses that share physical space and experience positive and/or negative interactions with each other. Although the corn microbiome has been characterized, community changes that result from the application of fungal biocontrol strains, such as non-aflatoxigenic Aspergillus flavus, have not. In this study, we exposed field-grown corn to a non-aflatoxigenic strain (K49), a highly toxigenic strain (Tox4), and a combination of both strains. Two types of corn were treated, one that is susceptible to A. flavus infection and one that is resistant. We found that corn kernel communities (bacteria and fungi) for both corn types were significantly impacted by the introduction of A. flavus. Overall, bacterial communities were more diverse than fungal communities. Organisms that are beneficial to corn plants, like the fungus Sarocladium, responded well to the presence of A. flavus biocontrol strains, indicating they could be used to enhance biocontrol efficacy, while also helping to fight harmful organisms.

Technical Abstract: In this study, we silk-inoculated field-grown maize separately with a non-aflatoxigenic biocontrol strain (K49), a highly toxigenic strain (Tox4), and a combination of both A. flavus strains. Two maize inbreds were treated, A. flavus-susceptible B73 and A. flavus-resistant CML322. We assessed the impacts of A. flavus introduction on the epibiota and endobiota of their maize kernels and found that the native microbial communities were significantly affected, irrespective of genotype or sampled tissue. Overall, bacteriomes exhibited greater diversity of genera than mycobiomes. The abundance of certain genera was unchanged by treatment, including genera of bacteria (e.g., Enterobacter, Pantoea) and fungi (e.g., Sarocladium, Meyerozyma) that are known to be beneficial, antagonistic, or both on plant growth and health. Beneficial microbes like Sarocladium that responded well to A. flavus biocontrol strains are expected to enhance biocontrol efficacy, while also displacing/antagonizing harmful microbes.