Aspergillus flavus growing on corn kernels

GENETICS OF ASPERGILLUS RESISTANCE

Aspergillus is a common mold that is normally associated with soils and decaying vegetation.  However, it will infect living plants when conditions for its growth are favorable, most notably when plants are exposed to high humidity over a long period of time or are damaged due to drought or other stressors.  Growth of Aspergillus on plants can lead to the buildup of aflatoxins, compounds secreted by the growing fungi.  Aflatoxins are toxic and carcinogenic to animals.

We recently began a collaboration with Dr. Paul Williams and his colleagues at the USDA-ARS's Corn Host Plant Resistance Research Unit (CHPRRU) at Mississippi State University.  Specifically, we are working with the CHPRRU to study maize genes involved in resistance to Aspergillus flavus infection (and subsequently aflatoxin contamination).  Through a newly-funded competitive grant from the Mississippi Corn Promotion Board, MGEL will construct a 4X BAC library for the Aspergillus/aflatoxin-resistant line Mp313E.  BAC macroarrays will then be screened with QTL markers and overgos designed from ESTs that are up- and down-regulated in Aspergillus-challenged Mp313E as compared to an Aspergillus-challenged susceptible maize line.  Through a combination of mapping techniques, MGEL hopes to identify and sequence intact candidate resistance genes.