Table 1.
Expression of EPSPS cDNA in glyphosate-resistant and -susceptible A. palmeri is not affected by glyphosate treatment
| Biotype | Glyphosate | Shikimate 8 HAT (Δ ng shikimate μL−1) | EPSPS expression relative to ALS 8 HAT [2(ΔCt)] |
| Susceptible | − | 0.5 (0.3) | 0.8 (0.1) |
| Susceptible | + | 15.0 (1.8) | 0.8 (0.1) |
| Resistant | − | −0.9 (0.6) | 35.1 (4.7) |
| Resistant | + | −0.5 (0.3) | 35.0 (5.7) |
EPSPS cDNA was measured relative to ALS using quantitative PCR and expressed as 2^ΔCt (threshold cycle), where ΔCt = (Ct, ALS − Ct, EPSPS). The + glyphosate data were obtained 8 HAT with 0.4 kg ha−1 glyphosate, and the − glyphosate data were obtained 8 HAT with water. Means and standard errors (in parentheses) are from two experimental runs with four biologic replicates each.