Figure 4.

dHax3.RR.HD₁₂ DNA-Binding Activity and Efficiency.

Sequence of effector dHax3.RR.HD₁₂ and T-preceded EBE boxes, polyA, G, T, and C, in minimal Bs3 promoter (mBs3) that drives uidA reporter gene expression. The constitutive 35S-driven dHax3.RR.HD₁₂ clone was co-delivered, separately, with mBs3 containing polyA, G, T, or C EBE clone via A. tumefaciens into N. benthamiana leaves. dHax3.RR.HD₁₂ alone and dHax3.RR.HD₁₂ with mBs3 served as negative controls and dHax3 with mBs3.dHax3.EBE served as positive control. Leaf discs were collected 2 d post infiltration; half were stained with X-Gluc and half were used for quantitative measurement of GUS activities. The results show that the dHax3.RR.HD₁₂ effector strongly activated the expression of mBs3polyC-driven uidA reporter. These experiments were repeated at least three times, with similar results. RR, Ralstonia repeat; EBE, DNA-binding element.