RNA Sequencing of Contaminated Seeds Reveals the State of the Seed Permissive for Pre-Harvest Aflatoxin Contamination and Points to a Potential Susceptibility Factor.
Pre-harvest aflatoxin contamination (PAC) is a major problem facing peanut production worldwide. Produced by the ubiquitous soil fungus,Aspergillus flavus, aflatoxin is the most naturally occurring known carcinogen. The interaction between fungus and host resulting in PAC is complex, and breeding for PAC resistance has been slow. It has been shown that aflatoxin production can be induced by applying drought stress as peanut seeds mature. We have implemented an automated rainout shelter that controls temperature and moisture in the root and peg zone to induce aflatoxin production. Using polymerase chain reaction (PCR) and high performance liquid chromatography (HPLC), seeds meeting the following conditions were selected: infected withAspergillus flavusand contaminated with aflatoxin; and not contaminated with aflatoxin. RNA sequencing analysis revealed groups of genes that describe the transcriptional state of contaminated vs. uncontaminated seed. These data suggest that fatty acid biosynthesis and abscisic acid (ABA) signaling are altered in contaminated seeds and point to a potential susceptibility factor,ABR1, as a repressor of ABA signaling that may play a role in permitting PAC.
Department of Horticulture and Institute of Plant Breeding, Genetics & Genomics, The University of Georgia, Tifton, GA 31793, USA. jclev@uga.edu.
Josh
J
Clevenger
Department of Horticulture and Institute of Plant Breeding, Genetics & Genomics, The University of Georgia, Tifton, GA 31793, USA. kath1290@uga.edu.
Kathleen
K
Marasigan
Department of Crop and Soil Sciences, The University of Georgia, Tifton, GA 31793, USA. vliakos@uga.edu.
Vasileios
V
Liakos
USDA-ARS National Peanut Research Laboratory, Dawson, GA 39842, USA. victor.sobolev@ars.usda.gov.
Victor
V
Sobolev
Department of Crop and Soil Sciences, The University of Georgia, Tifton, GA 31793, USA. yiorgos@uga.edu.
George
G
Vellidis
USDA-ARS, Crop Genetics and Breeding Res. Unit, Tifton, GA 31793, USA. corley.holbrook@ars.usda.gov.
Corley
C
Holbrook
Department of Horticulture and Institute of Plant Breeding, Genetics & Genomics, The University of Georgia, Tifton, GA 31793, USA. pozias@uga.edu.
Peggy
P
Ozias-Akins
D000040:Abscisic Acid / Q000096:biosynthesis; D000348:Aflatoxins / Q000032:analysis*; D010367:Arachis / Q000737:chemistry / Q000235:genetics / Q000382:microbiology; D001231:Aspergillus flavus / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D018744:DNA, Plant / Q000235:genetics; D005227:Fatty Acids / Q000096:biosynthesis; D005506:Food Contamination; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D022661:RNA, Untranslated / Q000235:genetics; D012639:Seeds / Q000737:chemistry / Q000235:genetics / Q000382:microbiology; D017423:Sequence Analysis, RNA
D000348:Aflatoxins; D018744:DNA, Plant; D005227:Fatty Acids; D022661:RNA, Untranslated; D000040:Abscisic Acid
Arachis hypogaea; Aspergillus; RNA-seq; aflatoxin; non-coding RNA; uHPLC