Fig. 2: DSBR deficiency causes increased EGT in somatic cells.

a, Workflow of the genetic screens for EGT based on kanamycin (Kan) selection. Plants regenerating during primary selection (white arrow) are considered candidate EGT lines. Lines that also regenerate during secondary selection are considered genuine EGT events, while lines that are kanamycin sensitive during secondary selection (black arrows) are considered ‘escapes’. Scale bars, 3 cm. b, Frequencies of gene transfer events (coloured) and escapes (grey) per hundred leaf pieces (hlp) in each genotype at the end of Experiments 1 and 2. N_lp, number of leaf pieces screened. c,d, Change in the cumulative FGT during primary selection in Experiments 1 (c) and 2 (d). The calculations of FGT per cell number are based on previous estimates of cell counts in tobacco leaves (Methods). The change of FGT over time per genotype was analysed through simultaneous linear regressions (Models 1 and 2, Supplementary Table 1). Each data point corresponds to an FGT calculated using the total number of EGT events that had been obtained up to that day (cumulative FGT). The coloured shading corresponds to the 95% confidence interval of the cumulative FGT, calculated according to the values fitted by Models 1 and 2 at each time point. The filled green circle represents a single FGT value for Nt-RB98 (equivalent to one event per hlp) reported in a previous study¹⁸, based on a measurement made at the end of a fixed primary selection period of 60 days (in an otherwise similar experimental set-up; the time dependence of FGT measurements was unknown at the time)¹⁸.