Location: Food and Feed Safety ResearchTitle: Host-induced silencing of Aspergillus flavus genes to control preharvest aflatoxin contamination in maize
|Rajasekaran, Kanniah - Rajah|
|Wei, Qijian - Mei Mei|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/6/2019
Publication Date: N/A
Technical Abstract: RNA interference (RNAi)-mediated host-induced gene silencing (HIGS) of key Aspergillus flavus genes to reduce fungal virulence, growth and/or toxin production by the fungus in susceptible crops such as maize is a promising and consumer-friendly approach to control dangerous levels of carcinogenic aflatoxins (AF). This RNAi-mediated technology does not require production of a foreign protein in the host plant; as such, food and feed produced from these resistant lines of maize should be more acceptable to regulatory agencies and consumers. For prevention of AF contamination in maize, we targeted A. flavus genes that are critical to its growth, development, and AF biosynthesis. These include the veA and nsdC genes, both global regulators required for normal A. flavus development and AF production and the a-amylase gene, required for starch degradation by the invading fungus, among others. Fungal growth was monitored in transgenic kernels using a green fluorescent protein (GFP)-expressing A. flavus and AF measurement was carried out by UPLC. Results from transgenic kernel infection studies demonstrated significant reductions in fungal growth, invasion, and AF production in transgenic maize RNAi lines that targeted fungal genes critical for growth and/or AF biosynthesis, either alone or in combination. Further details on effective reduction in aflatoxin contamination of maize kernels from several transgenic lines will be presented.