Mitotic-inhibiting herbicide response variation in goosegrass (Eleusine indica) with a Leu-136-Phe substitution in α-tubulin

Abstract

Dithiopyr and dinitroanilines are preemergence-applied, mitotic-inhibiting herbicides used to control goosegrass [Eleusine indica (L.) Gaertn.]) in turfgrass. A suspected resistant E. indica population was collected from a golf course putting green and was evaluated for possible resistance to dithiopyr and prodiamine. After dose-response evaluation, the α-tubulin gene was sequenced for known target-site mutations that have been reported to confer resistance to mitotic-inhibiting herbicides. A mutation was discovered that resulted in an amino acid substitution at position 136 from leucine to phenylalanine (Leu136-Phe). Previous research has indicated that Leu136-Phe does confer resistance to dinitroaniline herbicides. The level of resistance indicated by regression models and I50 values indicates that there is a 54.1-, 4.7-, >100-, and >100-fold resistance to dithiopyr, prodiamine, pendimethalin, and oryzalin, respectively when compared to the susceptible population based on seedling emergence response and 88.4-, 7.8-, >100-, and >100-fold resistance to dithiopyr, prodiamine, pendimethalin, and oryzalin, respectively when compared to the susceptible population based on biomass reduction response. This is the first report of less resistance to prodiamine compared to pendimethalin or oryzalin due to a target-site α-tubulin mutation and the first report of a target-site α-tubulin mutation associated with dithiopyr resistance.

Unveiling the Possible Oryzalin-Binding Site in the α-Tubulin of Toxoplasma gondii

“…It is well known that dinitroaniline derivatives exhibit herbicidal and antiprotozoal activity selectively binding to α-tubulin. 25 The tubulin polymerization inhibitory activity of these compounds has been observed in plants such as A. aequalis (water foxtail), 26 L. rigidum (annual grass), 25 Eleusine indica (goosegrass), 31 and Setaria viridis (green foxtail). 32 Similarly, treatment with dinitroaniline derivatives has shown microtubule disruption activity in protozoa with low half-maximal inhibitory concentrations (IC 50 ).…”

“…aequalis (water foxtail), L. rigidum (annual grass), Eleusine indica (goosegrass), and Setaria viridis (green foxtail) . Similarly, treatment with dinitroaniline derivatives has shown microtubule disruption activity in protozoa with low half-maximal inhibitory concentrations (IC 50 ).…”

Target-site and non–target site mechanisms of pronamide resistance in annual bluegrass (Poa annua) populations from Mississippi golf courses

“…Uribe et al (1998) reported that the α-tubulin gene is expressed at different levels and locations within the plant. Russell (2021) reported that three P. annua populations were 1.6-, 16.5-, and 4.6-fold resistant to prodiamine relative to the susceptible population and concluded that the variation in resistance levels between populations could be explained by both gene copy variation and intra-plant variation in gene expression. This same rationale could also be extended to the absence of prodiamine resistance in BS-S; however, gene expression was not measured in our study.…”

“…Target-site mutations for pronamide resistance have not been reported. Mutations on the α-tubulin gene conferring dinitroaniline herbicide resistance are reported at position 125 from leucine to methionine (Hashim et al 2012), at position 136 from phenylalanine to leucine (Délye et al 2004), at position 202 from valine to phenylalanine (Fleet et al 2018;Hashim et al 2012), at position 239 from threonine to isoleucine (Anthony et al 1998;Breeden et al 2017a;Délye et al 2004;Fleet et al 2018;Russell 2021;Yamamoto et al 1998), at position 243 from arginine to methionine and arginine to lysine (Chu et al 2018), and at position 268 from methionine to threonine (Yamamoto et al 1998), NTSR involves a change in a plant's physiological response to herbicides and can occur due to decreased uptake or translocation, sequestration, or metabolic detoxification of the herbicide in the plant (Délye 2013;Van Eerd et al 2003;Yuan et al 2007). According to some, herbicide detoxification may be the most threatening NTSR mechanism, because it can bestow multiple-herbicide resistance to numerous herbicide modes of action (Ma et al 2013;Preston 2004;Preston et al 1996).…”

Survey of target site resistance alleles conferring resistance in Poa annua

“…In mitotic-inhibiting herbicides, Thr239 and Met268 mutations on the α-tubulin gene both provide an intermediate to high-level of resistance to dinitroaniline herbicides but have not been described as providing cross-resistance to pyridine herbicides (Yamamoto et al, 1998). The Leu136 mutation, however, has been shown to provide varying levels of resistance to herbicides in both the dinitroaniline and pyridine chemical families (Russell et al, 2021).…”