Glyphosate resistance in Eleusine indica (L.) Gaertn. from different origins and polymerase chain reaction amplification of specific alleles

Abstract

Glyphosate-resistant populations of Eleusine indica (L.) Gaertn. were found in 4 areas in Malaysia that had received repeated applications of glyphosate for a period ranging from 5 to 15 years. The resistance ratios calculated from dose-response experiments were 2.9 (Chaah), 2.1 (Lenggeng), 3.3 (Bidor), and 2.8 (Temerloh). Two-point mutations were detected in position 875 within the 5-enolpyruvylshikimate 3-phosphate synthase (EPSPS) gene resistant population, causing a C to T transition leading to Pro106 to Ser106 substitution in Bidor and Temerloh or C to A transversion leading to Pro106 to Thr106 substitution in Chaah. Sequence comparisons of the 3115 bp of the EPSPS gene revealed identical sequences in both the susceptible (S) and resistant (R) populations of Lenggeng. The identical sequences in both the Lenggeng populations, S and R, suggest that the resistance mechanism found in Lenggeng R may be different from Chaah R, Bidor R, and Temerloh R. The polymerase chain reaction (PCR) amplification of specific alleles (PASA) was developed to detect 2 distinct single-point mutations, probably conferring herbicide resistance in Chaah R, Bidor R, and Temerloh R. PASA profiles showed only one DNA fragment for the entire S population and 2 different additional fragments, each specific for one resistance allele, for the R population.

Evolution of a Double Amino Acid Substitution in the 5-Enolpyruvylshikimate-3-Phosphate Synthase in Eleusine indica Conferring High-Level Glyphosate Resistance

“…This TIPS EPSPS enables plants to survive high glyphosate rates. Indeed, many glyphosateresistant E. indica populations in Malaysia and other countries have been found to possess mutations at P106 (Baerson et al, 2002;Ng et al, 2003Ng et al, , 2004Kaundun et al, 2008), and in Malaysia, glyphosate was used frequently (every month) and continually (5-10 years) at increased glyphosate rates (0.72-1.92 kg ha…”

“…Low-level glyphosate resistance due to the EPSPS P106 mutations was reported in Malaysian E. indica (Baerson et al, 2002;Ng et al, 2004). Recently, we reported a highly (more than 10-fold the recommended rates) glyphosateresistant Malaysian E. indica population (Jalaludin et al, 2015).…”

“…) to control E. indica (Ng et al, 2004). Therefore, evolution of at least the TIPS mutation can be expected from other glyphosate-resistant E. indica populations in Malaysia and other countries.…”

“…Since the first identification of a resistance-endowing EPSPS point mutation, P106S, in a glyphosate-resistant Eleusine indica population (Baerson et al, 2002), several other resistance-endowing singleamino acid substitutions at P106 (P106T, P106A, and P106L) have been reported in glyphosate-resistant weeds (e.g. Ng et al, 2004;Yu et al, 2007;Kaundun et al, 2011; for review, see Sammons and Gaines, 2014). These singlecodon EPSPS resistance mutations only endow low-level glyphosate resistance (2-to 3-fold the recommended rates).…”

Mechanism of Resistance to Glyphosate in Lolium perenne from Argentina

“…Accordingly, no changes in the nucleotide sequences associated with Gly-101, Thr-102, Pro-106, Gly-144, and Ala-192 were found in either case. The affinity between the glyphosate molecule and EPSPS from resistant plants was not affected, unlike in other cases of glyphosate resistance (Ng et al, 2004;Yu et al, 2007;Simarmata and Penner, 2008;Kaundun et al, 2011).…”