Differential Expression of Genes Associated With Degradation Enhancement of Imazethapyr in Barnyardgrass (Echinochloa crus-galli)

Abstract

The understanding of mechanism of herbicide resistance in weeds is essential for adequate or innovative weed management practices. The aim of this study was to identify and analyze the expression of genes related to degradation enhancement of imazethapyr in barnyardgrass (Echinochloa crus-galli L. Beauv.). One susceptible (SUSSP01) and two populations previouslly identified as resistant to imazethapyr (ARRGR01 and PALMS01) were used. Gene expression of CYP and GST, the translation initiating factor eIF4B, and ALS genes were evaluated after imazethapyr spraying. A reference gene stability analysis was carried out, wherein the genes 18S and actin showed to be more stable in response to the population and herbicide treatment. The gene expression analysis was performed by qRT-PCR. There was no difference in the relative expression of the ALS gene. The CYP81A6 and GSTF1 genes showed higher relative expression in the resistant populations. The CYP81A6 gene had expression 9.61 and 8.44 higher in the resistant populations ARRGR01 and PALMS01, respectively, in comparison with the untreated susceptible population. The expression of this gene was induced by spraying the herbicide imazethapyr. The GSTF1 gene showed higher relative expression in PALMS01 population, reaching 12.30 times higher in plants treated with imazethapyr in relation to untreated susceptible population. The expression of eIF4B gene in the resistant populations treated with imazethapyr was about six times higher than observed in susceptible population. The high relative expression of CYP81A6 and GSTF1 genes indicate the importance of degradation enhancement for the resistance of barnyargrass to imazethapyr.

Effects of sorghum residue in presence of pre-emergence herbicides on emergence and biomass of Echinochloa colona and Chloris virgata

“…PRE herbicides play an integral role in weed control within conservation cropping systems. PRE herbicides such as imazethapyr [(Spinnaker), acetolactate synthase inhibitors], isoxaflutole [(Balance), 4-hydroxyphenyl-pyruvate dioxygenase inhibitors], S-metolachlor [(Dual Gold), cell division/ very long-chain fatty acid inhibitors], pendimethalin [(Rifle), microtubule assembly inhibitors] and prosulfocarb + metolachlor [(Boxer Gold), inhibitors of lipid synthesis and cell division/ very long-chain fatty acid inhibitors] are recommended for the control of grass weeds such as E. colona and C. virgata in many summer crops [14][15][16][17][18][19]. In this study, herbicides with different water solubility (mg/L at 20˚C) [pendimethalin (0.33), isoxaflutole (6), prosulfocarb + metolachlor (16), metolachlor (480), and while metolachlor (200), isoxaflutole (145) and imazethapyr (1.4-173) tend to highly move with soil water [20].…”

Target-Site Mutations and Expression of ALS Gene Copies Vary According to Echinochloa Species

“…Eight reference genes (Rubisco, Actin, 18S, CAP, Tubuline, GAPDH, EF1 and Ubiquitine) chosen among those previously tested on Echinochloa spp. [28] were tested on the cDNA of two populations (161S and 45R). Serial dilutions of cDNA template (1:100, 1:50, 1:25 and 1:6.25) were tested to set up the appropriate experimental conditions.…”

Rapid Reduction of Herbicide Susceptibility in Junglerice by Recurrent Selection with Sublethal Dose of Herbicides and Heat Stress

“…It is possible that other CytP450 genes are involved, which are not included in the selection of primary target genes. Dalazen et al [80] demonstrated the importance of degradation enhancement for resistance of Echinochloa crus-galli to imazethapyr in terms of relatively high expression of CYP81A6 and GSTF1 genes. Wright et al [59] studying a biotype of junglerice with resistance to four herbicides (imazamox, fenoxaprop-P-ethyl, quinclorac and propanil) demonstrated that for two of these herbicides (imazamox and quinclorac) the resistance was reduced when the herbicide was applied with a cytochrome P450 inhibitor (malathion).…”