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Drought stress and aflatoxin contamination: transcriptional responses of Aspergillus flavus to oxidative stress are related to stress tolerance and aflatoxin production capability

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Relation http://oar.icrisat.org/10290/
 
Title Drought stress and aflatoxin contamination: transcriptional responses of Aspergillus flavus
to oxidative stress are related to stress tolerance and aflatoxin production capability
 
Creator Fountain, J C
Bajaj, P
Yang, L
Pandey, M K
Kumar, V
Jayale, A S
Chitikineni, A
Lee, R D
Scully, B T
Kemerait, R C
Varshney, R K
Guo, B
 
Subject Groundnut
Oil seeds
Aflatoxins
 
Description Oilseed crops such as maize and peanut are staple food crops
which are vital for global food security. The contamination of
these crops with carcinogenic aflatoxins during infection by Aspergillus
flavus under drought stress conditions is a serious threat
to the safety of these commodities. In order to better understand
the role of aflatoxin production in the biology of this pathogen
under environmental stress, a collaborative transcriptome project
was undertaken to examine the transcriptional responses of
toxigenic and atoxigenic isolates of A. flavus to oxidative stress.
Selected isolates were cultured in aflatoxin production-conducive
and non-conducive media amended with varying levels of
H2O2. Isolates which possessed greater tolerance to H2O2
stress and aflatoxin production capability exhibited fewer differentially
expressed genes (DEGs) than those which possessed
less tolerance and lower aflatoxin production. Primary metabolic
mechanisms were also stimulated in response to stress along
with antioxidant enzyme-encoding genes. Genes related to
fungal development such as aminobenzoate degradation genes
and conidiation regulators were also differentially expressed
in response to stress. Secondary metabolite biosynthetic processes
also formed a large component of the isolate responses
to stress including those for aflatoxin, aflatrem, and kojic acid.
Co-expression analyses also showed that aflatoxin biosynthetic
gene expression along with antioxidant genes were highly correlated
with toxigenic isolate biomass under variable stresses.
These results along with others in the literature suggest that the
production of these secondary metabolites may provide supplemental
oxidative stress alleviation. Additional data validation using
proteomics, metabolomics and whole genome resequencing
(WGRS) approaches will also be discussed.
 
Date 2017-02
 
Type Conference or Workshop Item
PeerReviewed
 
Format application/pdf
 
Language en
 
Rights —
 
Identifier http://oar.icrisat.org/10290/1/Abstract_Book_120.pdf
Fountain, J C and Bajaj, P and Yang, L and Pandey, M K and Kumar, V and Jayale, A S and Chitikineni, A and Lee, R D and Scully, B T and Kemerait, R C and Varshney, R K and Guo, B (2017) Drought stress and aflatoxin contamination: transcriptional responses of Aspergillus flavus to oxidative stress are related to stress tolerance and aflatoxin production capability. In: InterDrought-V, February 21-25, 2017, Hyderabad, India.