title: Quantitative expression analysis of GH3, a gene induced by plant growth regulator herbicides in soybean.
abstract: Symptoms resembling off-target plant growth regulator (PGR) herbicide injury are frequently found in soybean fields, but the causal agent is often difficult to identify. The expression of GH3, an auxin-regulated soybean gene, was quantified from soybean leaves injured by PGR herbicides using real-time RT-PCR. Expression of GH3 was analyzed to ascertain its suitability for use in a diagnostic assay to determine whether PGR herbicides are the cause of injury. GH3 was highly induced by dicamba within 3 days after treatment (DAT) and remained high at 7 DAT, but induction was much lower at 17 DAT. GH3 was also highly induced at 7 DAT by dicamba + diflufenzopyr, and to a lesser extent by the other PGR herbicides clopyralid and 2,4-D. The non-PGR herbicides glyphosate, imazethapyr, and fomesafen did not significantly induce GH3 expression above a low constitutive level. These results indicate that a diagnostic assay for PGR herbicide injury based on overexpression of auxin-responsive genes is feasible, and that GH3 is a potential candidate from which a diagnostic assay could be developed. However, time course analysis of GH3 expression indicates the assay would be effective for a limited time after exposure to the herbicide.
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Kelley
authors.forename: Kris N
authors.initials: KN
authors.lastname: Lambert
authors.forename: Aaron G
authors.initials: AG
authors.lastname: Hager
authors.forename: Dean E
authors.initials: DE
authors.lastname: Riechers
mesh_terms: D015870:Gene Expression / Q000187:drug effects*; D006540:Herbicides / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D030262:Soybean Proteins / Q000235:genetics*; D013025:Glycine max / Q000378:metabolism*
chemical_list: C070797:GH3 protein, soybean; D006540:Herbicides; D010937:Plant Growth Regulators; D030262:Soybean Proteins