Proline-106 EPSPS Mutation Imparting Glyphosate Resistance in Goosegrass (Eleusine indica) Emerges in South America. Issue 1 (18th December 2018)

• Record Type: Journal Article
• Authors: Takano, Hudson K.; Mendes, Rafael R.; Scoz, Leonardo B.; Lopez Ovejero, Ramiro F.; Constantin, Jamil; Gaines, Todd A.; Westra, Philip; Dayan, Franck E.; Oliveira, Rubem S.
• Is Part Of: Weed science. Volume 67:Issue 1(2019)
• Page Start: 48
• Page End: 56
• Publication Date: 2018-12-18
• Subjects: Prashant Jha, Montana State University; 5-enolpyruvylshikimate-3-phosphate synthase, -- absorption and translocation, -- EPSPS, -- glyphosate metabolism, -- herbicide-resistance detection, shikimate accumulation, -- target-site resistance; 632.505
• DOI: 10.1017/wsc.2018.71
• Languages: English
• ISSNs: 0043-1745

Abstract

Abstract: Glyphosate-resistant (GR) goosegrass [ Eleusine indica (L.) Gaertn.] was recently identified in Brazil, but its resistance mechanism was unknown. This study elucidated the resistance mechanism in this species and developed a molecular marker for rapid detection of this target-site resistance trait. The resistance factor for the resistant biotype was 4.4-fold compared with the glyphosate-susceptible (GS) in greenhouse dose–response experiments. This was accompanied by a similar (4-fold) difference in the levels of in vitro and in planta shikimate accumulation in these biotypes. However, there was no difference in uptake, translocation, or metabolism of glyphosate between the GS and GR biotypes. Moreover, both biotypes showed similar values for 5-enolpyruvylshikimate-3-phosphate synthase ( EPSPS ) copy number and transcription. Sequencing of a 330-bp fragment of the EPSPS gene identified a single-nucleotide polymorphism that led to a Pro-106-Ser amino acid substitution in the enzyme from the GR biotype. This mutation imparted a 3.8-fold increase in the amount of glyphosate required to inhibit 50% of EPSPS activity, confirming the role of this amino acid substitution in resistance to glyphosate. A quantitative PCR–based genotyping assay was developed for the rapid detection of resistant plants containing this Pro-106-Ser mutation.