Dhiraj Thakare1, Jianwei Zhang1,2, Rod A. Wing1,2, Peter J. Cotty3 and Monica A. Schmidt1,*
1BIO5 Institute, School of Plant Sciences, University of Arizona, 1657 E. Helen Street, Tucson, AZ 85721, USA.
2Arizona Genomics Institute, 1657 E. Helen Street, Tucson, AZ 85721, USA.
3Agricultural Research Service, U.S. Department of Agriculture, and School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA.
↵*Corresponding author. Email: firstname.lastname@example.org
Science Advances 10 Mar 2017:
Vol. 3, no. 3, e1602382
Aflatoxins, toxic secondary metabolites produced by some Aspergillus species, are a universal agricultural economic problem and a critical health issue. Despite decades of control efforts, aflatoxin contamination is responsible for a global loss of millions of tons of crops each year. We show that host-induced gene silencing is an effective method for eliminating this toxin in transgenic maize. We transformed maize plants with a kernel-specific RNA interference (RNAi) gene cassette targeting the aflC gene, which encodes an enzyme in the Aspergillus aflatoxin biosynthetic pathway. After pathogen infection, aflatoxin could not be detected in kernels from these RNAi transgenic maize plants, while toxin loads reached thousands of parts per billion in nontransgenic control kernels. A comparison of transcripts in developing aflatoxin-free transgenic kernels with those from nontransgenic kernels showed no significant differences between these two groups. These results demonstrate that small interfering RNA molecules can be used to silence aflatoxin biosynthesis in maize, providing an attractive and precise engineering strategy that could also be extended to other crops to improve food security.