Journal or Publishing Institution: Pest Management Science
Study: http://www.ncbi.nlm.nih.gov/pubmed/24497375
Author(s): Nandula, V.K., Wright, A.A., Bond, J.A., Ray, J.D., Eubank, T.W. and Molin, W.T.
Article Type: Peer Reviewed Study
Record ID: 1712
Abstract:
BACKGROUND:
Amaranthus spinosus, a common weed of pastures, is a close relative of Amaranthus palmeri, a problematic agricultural weed with widespread glyphosate resistance. These two species have been known to hybridize, allowing for transfer of glyphosate resistance. Glyphosate-resistant A. spinosus was recently suspected in a cotton field in Mississippi.
RESULTS:
Glyphosate-resistant A. spinosus biotypes exhibited a fivefold increase in resistance compared with a glyphosate-susceptible biotype. EPSPS was amplified 33-37 times and expressed 37 times more in glyphosate-resistant A. spinosus biotypes than in a susceptible biotype. The EPSPS sequence in resistant A. spinosus plants was identical to the EPSPS in glyphosate-resistant A. palmeri, but differed at 29 nucleotides from the EPSPS in susceptible A. spinosus plants. PCR analysis revealed similarities between the glyphosate-resistant A. palmeri amplicon and glyphosate-resistant A. spinosus.
CONCLUSIONS:
Glyphosate resistance in A. spinosus is caused by amplification of the EPSPS gene. Evidence suggests that part of the EPSPS amplicon from resistant A. palmeri is present in glyphosate-resistant A. spinosus. This is likely due to a hybridization event between A. spinosus and glyphosate-resistant A. palmeri somewhere in the lineage of the glyphosate-resistant A. spinosus plants. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Keywords: Amaranthus spinosus, Cotton, Gene Transfer, Biotypes, Pastures, Glyphosate, Interspecific Hybridization, Nucleotides, Genes, Weeds; Amaranthus palmeri, Polymerase Chain Reaction, Mississippi; 3-Phosphoshikimate 1-Carboxyvinyltransferase, Amaranthus, Gene Amplification, Gene Dosage, Glycine, Herbicide Resistance, Herbicides, Genetic Hybridization, Mississippi, Plant Weeds; Drug Effects, Enzymology, Genetics, Pharmacology; EPSPS, Introgression
Citation: Nandula, V.K., Wright, A.A., Bond, J.A., Ray, J.D., Eubank, T.W. and Molin, W.T., 2014. EPSPS amplification in glyphosate‐resistant spiny amaranth (Amaranthus spinosus): a case of gene transfer via interspecific hybridization from glyphosate‐resistant Palmer amaranth (Amaranthus palmeri). Pest Management Science, 70(12), pp.1902-1909.
