title: Aflatoxin-free transgenic maize using host-induced gene silencing.
abstract: Aflatoxins, toxic secondary metabolites produced by someAspergillusspecies, 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 theaflCgene, which encodes an enzyme in theAspergillusaflatoxin 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.
authors.affiliation: BIO5 Institute, School of Plant Sciences, University of Arizona, 1657 E. Helen Street, Tucson, AZ 85721, USA.
authors.forename: Dhiraj
authors.identifier: 0000-0002-4870-5064
authors.initials: D
authors.lastname: Thakare
authors.affiliation: BIO5 Institute, School of Plant Sciences, University of Arizona, 1657 E. Helen Street, Tucson, AZ 85721, USA.; Arizona Genomics Institute, 1657 E. Helen Street, Tucson, AZ 85721, USA.
authors.forename: Jianwei
authors.identifier: 0000-0001-8030-5346
authors.initials: J
authors.lastname: Zhang
authors.affiliation: BIO5 Institute, School of Plant Sciences, University of Arizona, 1657 E. Helen Street, Tucson, AZ 85721, USA.; Arizona Genomics Institute, 1657 E. Helen Street, Tucson, AZ 85721, USA.
authors.forename: Rod A
authors.identifier: 0000-0001-6633-6226
authors.initials: RA
authors.lastname: Wing
authors.affiliation: Agricultural Research Service, U.S. Department of Agriculture, and School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Peter J
authors.identifier: 0000-0003-3887-833X
authors.initials: PJ
authors.lastname: Cotty
authors.affiliation: BIO5 Institute, School of Plant Sciences, University of Arizona, 1657 E. Helen Street, Tucson, AZ 85721, USA.
authors.forename: Monica A
authors.initials: MA
authors.lastname: Schmidt
mesh_terms: D000348:Aflatoxins / Q000096:biosynthesis / Q000235:genetics; D001230:Aspergillus / Q000235:genetics / Q000378:metabolism; D020868:Gene Silencing; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D018749:RNA, Plant / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000235:genetics; D003313:Zea mays / Q000235:genetics / Q000378:metabolism / Q000382:microbiology
chemical_list: D000348:Aflatoxins; D018749:RNA, Plant; D034741:RNA, Small Interfering
keywords: Aspergillus; Biotechnology; HIGS; aflatoxin; host-induced gene silencing; maize; mycotoxin