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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #326647

Title: Host-Induced Gene Silencing (HIGS) of aflatoxin synthesis genes in peanut and maize: use of RNA interference and genetic diversity of Aspergillus

item Arias De Ares, Renee
item Dang, Phat
item Sobolev, Victor

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/2/2016
Publication Date: 10/17/2016
Citation: Arias De Ares, R.S., Dang, P.M., Sobolev, V. 2016. Host-Induced Gene Silencing (HIGS) of aflatoxin synthesis genes in peanut and maize: use of RNA interference and genetic diversity of Aspergillus. Meeting Abstract. DOI: 10.4172/2161-0495.C1.018.

Interpretive Summary: This presentation will include a summary of several research projects including molecular tools to develop host-induced gene silencing in Aspergillus, a method to evaluate the effectiveness of RNA interference to reduce/eliminate aflatoxin, and genetic diversity studies of the pathogen as a mean to obtain DNA sequencing level information to better target gene silencing.

Technical Abstract: Approximately 4.5 billion people are chronically exposed to aflatoxins, these are powerful carcinogens produced by Aspergillus flavus and A. parasiticus. High levels of aflatoxins in crops result in approximately 100 million metric tons of cereals, ¬nuts, root crops and other agricultural products being destroyed or diverted to non-human consumption each year. We have targeted silencing of 5-genes in the aflatoxin biosynthesis pathway of Aspergillus by RNA interference (RNAi) from the plant host to reduce/eliminate aflatoxin accumulation in peanut and maize seeds. Given that no method existed to analyze the effectiveness of RNAi against aflatoxins, and that testing of hundreds of plants in the field under aflatoxin-conducive conditions is not an option in this case, we developed a method of challenging with aflatoxigenic Aspergillus the RNAi treated seeds, and then analyze those seeds by ultra-performance liquid chromatography (UPLC). In parallel, we developed a workflow to obtain information of those isolates at the DNA sequencing level. This workflow includes fungal isolation, 25 InDel fingerprinting followed by cluster analysis, and whole genome sequencing of clade representatives. This method also allows analysis of small seed pieces for gene expression by real-time PCR (RT-PCR) and small RNA sequencing. Solving the aflatoxin problem in crops would be equivalent to increasing food production by millions of tons that could be safely consumed instead of being discarded or diverted to other uses.