Fig. 2.

A 16-bp fragment of the rice Xa27 promoter mediates transcriptional activation via AvrXa27. (A) Graphical representation of the analyzed promoter constructs. Yellow arrows and boxes represent the Bs3 promoter and cds, respectively. The UPT_AvrBs3 and UPT_AvrXa27 boxes are shown as blue and black boxes, respectively. A black box with a white bar marks the UPT_AvrXa27* box of the xa27 promoter. Letters on yellow background represent Bs3 promoter sequence. The asterisk (*) marks the position where Xa27/xa27 promoter sequences were inserted. Bold-face black letters mark nucleotide polymorphisms between Xa27 and xa27. Red letters mark the predicted TATA box. The gray background highlights the minimal UPT_AvrXa27 box. “+” and “−” indicates the presence or absence of an HR in N. benthamiana upon codelivery of 35S promoter-driven avrXa27 gene. (B) In planta analysis of UPT_AvrXa27 box deletion constructs. Promoter constructs were delivered together with a 35S promoter-driven avrXa27 gene via A. tumefaciens into N. benthamiana leaves. Asterisks mark areas where only the avr but no R promoter constructs were infiltrated. Dashed lines mark the inoculated areas. Four days after inoculation, the leaves were harvested and cleared with ethanol to visualize the HR (dark areas).