Figure 1.

Glyphosate resistance analysis of EPSPS mutants via growth of E. coli transformant. DH5α was transformed with pBREP (wild type), pBREP-P106L, and pBREP-G101A. The transformants were cultured in liquid MOPS medium containing glyphosate in increased concentration gradients. Aliquots of culture sample were measured for OD₆₀₀ before (OD_b) and after (OD_a) 12 h of incubation in 37°C by vigorous vibration. Error bars represent the sd resulting from three repetitions. A, Bar chart; OD₆₀₀ increment was calculated as (OD_a − OD_b)/OD₀, in which OD₀ is the final value of OD₆₀₀ absent glyphosate. B, Curve chart; the curve was determined by fitting data of OD_b to f(x) = C + (D − C)/(1 + (x/LD₅₀)^b) (Seefeldt et al., 1995; Igor Pro 4.00), where C = lower limit, D = upper limit, LD₅₀ = 50% lethal dose, and b = slope of the curve at LD₅₀. The first and last points on the curve represent the data of OD₀ and OD_b.