Fig. 3

Foliar MYB transcription factor gene expression in Arabidopsis grown at different levels of CO₂, nitrate fertilization and wounding stress. Arabidopsis plants were grown under ambient (440 ppm) or elevated (880 ppm) carbon dioxide (CO₂) levels and fertilized with either 1 mM or 10 mM nitrate (1 mM N or 10 mM N). At 6 weeks, rosette leaves were mechanically damaged (mech. damaged, black bars) or untouched (control, white bars). Expression of transcription factors that regulate glucosinolate biosynthesis a) AtMYB28 b) AtMYB29 c) AtMYB76 d) AtMYB34 and e) AtMYB51. Statistical differences were determined by 3-factor analysis of variance (Additional file 4: Table 3). When interactions were significant (p ≤ 0.05), data were separated to show treatment effects. In CO₂ levels and nitrate fertilization treatments, only significant changes in gene expression are highlighted. Significant differences in response to treatments are denoted by alphabetical letters