Journal Article

Acetohydroxyacid synthase mutations conferring resistance to imidazolinone or sulfonylurea herbicides in sunflower

Berry, S, Slabaugh, M.B, Maes, N, Bruniard, J.M, Abratti, G, Miller, J.F, Kolkman, J.M, Olungu, C, Zambelli, A, Bushman, B.S

2004

Overview

Wild biotypes of cultivated sunflower (Helianthus annuus L.) are weeds in corn (Zea mays L.), soybean (Glycine max L.), and other crops in North America, and are commonly controlled by applying acetohydroxyacid synthase (AHAS)-inhibiting herbicides. Biotypes resistant to two classes of AHAS-inhibiting herbicides-imidazolinones (IMIs) or sulfonylureas (SUs)-have been discovered in wild sunflower populations (ANN-PUR and ANN-KAN) treated with imazethapyr or chlorsulfuron, respectively. The goals of the present study were to isolate AHAS genes from sunflower, identify mutations in AHAS genes conferring herbicide resistance in ANN-PUR and ANN-KAN, and develop tools for marker-assisted selection (MAS) of herbicide resistance genes in sunflower. Three AHAS genes (AHAS1, AHAS2, and AHAS3) were identified, cloned, and sequenced from herbicide-resistant (mutant) and -susceptible (wild type) genotypes. We identified 48 single-nucleotide polymorphisms (SNPs) in AHAS1, a single six-base pair insertion-deletion in AHAS2, and a single SNP in AHAS3. No DNA polymorphisms were found in AHAS2 among elite inbred lines. AHAS1 from imazethapyr-resistant inbreds harbored a C-to-T mutation in codon 205 (Arabidopsis thaliana codon nomenclature), conferring resistance to IMI herbicides, whereas AHAS1 from chlorsulfuron-resistant inbreds harbored a C-to-T mutation in codon 197, conferring resistance to SU herbicides. SNP and single-strand conformational polymorphism markers for AHAS1, AHAS2, and AHAS3 were developed and genetically mapped. AHAS1, AHAS2, and AHAS3 mapped to linkage groups 2 (AHAS3), 6 (AHAS2), and 9 (AHAS1). The C/T SNP in codon 205 of AHAS1 cosegregated with a partially dominant gene for resistance to IMI herbicides in two mutant x wild-type populations. The molecular breeding tools described herein create the basis for rapidly identifying new mutations in AHAS and performing MAS for herbicide resistance genes in sunflower.

• Publisher: Springer,Springer Nature B.V
• Subject: acetolactate synthase / Acetolactate Synthase - genetics / AHAS genes / Amino Acid Sequence / Arabidopsis thaliana / Base Sequence / Biological and medical sciences / chromosome mapping / Classical genetics, quantitative genetics, hybrids / Codon / DNA, Plant / DNA, Plant - genetics / DNA, Plant - isolation & purification / drug effects / Fundamental and applied biological sciences. Psychology / gene expression / Genes / Genes, Plant / Genetic aspects / Genetic Markers / Genetic research / Genetics / Genetics of eukaryotes. Biological and molecular evolution / Genomics / Glycine max / Helianthus / Helianthus - drug effects / Helianthus - genetics / Helianthus annuus / Herbicide resistance / Herbicides / Herbicides - toxicity / Hypoglycemic agents / Imidazolines / Imidazolines - toxicity / imidazolinone herbicides / Immunity, Innate / Immunity, Innate - genetics / isolation & purification / messenger RNA / Molecular Sequence Data / multigene family / Mutation / nucleotide sequences / Pteridophyta, spermatophyta / Sequence Alignment / Sequence Homology, Amino Acid / single nucleotide polymorphism / Single nucleotide polymorphisms / Sulfonylurea Compounds / Sulfonylurea Compounds - toxicity / sulfonylurea herbicides / toxicity / transferases / Vegetals / Zea mays