C → T transition rates in transgenic Arabidopsis line M4, after infection with different Agrobacterium strains for various time periods. A. After VOT infection. B. After XXX infection. Bars indicate the standard error of the mean of three biological repeats, each consisting of about 140-160 plants. Numbers on top of the bars show the respective mean values, not significantly different (P > 0.05), as analysed by Duncan’s multiple range test. Vertical axis shows the mutation rates. (PPT 125 kb)