Glyphosate Resistance in Tridax procumbens via a Novel EPSPS Thr-102-Ser Substitution

• DOI: 10.1021/acs.jafc.8b01651
• Publication Date: 2018-07-09T16:28:36Z
• Authors: Jingbo Li; Qiong Peng; Heping Han; Alex Nyporko; Tymofii Kulynych; Qin Yu; Stephen Powles
• Keywords: Threonine; 0106 biological sciences; 0301 basic medicine; Glyphosate; Herbicides; Amino Acid Motifs; Glycine; Mutation, Missense; Asteraceae; 01 natural sciences; Phosphoenolpyruvate; 03 medical and health sciences; Amino Acid Substitution; Serine; 3-Phosphoshikimate 1-Carboxyvinyltransferase; Herbicide Resistance; Plant Proteins

This study confirmed the first case of glyphosate resistance in Tridax procumbens and investigated glyphosate-resistance mechanisms. Sequencing cloning full 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) coding sequences revealed a point mutation (ACC to TCC) at amino acid position 102, resulting novel Thr-102-Ser substitution. Other possible mechanisms (i.e., target-site EPSPS-gene overexpression, nontarget-site differential uptake translocation) were also examined unlikely be involved this population. Structural modeling wild-type mutant EPSPS complex with phosphoenolpyruvate (PEP) that substitution weakly decreased affinity glyphosate, but sharply increased natural substrate, PEP. Therefore, is very likely responsible for observed tetraploid weed species via dual reducing binding favoring PEP EPSPS.