Figure 5.

Transient expression of the NbCAT1 and GmCAT1 genes alleviates PsCRN63-triggered plant PCD. A, Suppression of PsCRN63-induced PCD by NbCAT1 and GmCAT1. GFP was used as a negative control and PsCRN115 as a positive control. Leaves of N. benthamiana were infiltrated with A. tumefaciens carrying the corresponding constructs. The photographs was taken at 4 d after infiltration. The numbers in each circled area represent summary data showing the number of infiltrated area(s) exhibiting cell death over the total number of leaf areas infiltrated with a particular construct or combination of constructs. B, The presence of the PsCRN63 protein was confirmed by immunoblotting using anti-HA antibodies. P, Ponceau S staining of the membrane to show equal loading. C, Quantification of PCD by measurement of electrolyte leakage. N. benthamiana leaves were agroinfiltrated with the corresponding constructs. Electrolyte leakage from the infiltrated leaf discs was measured as a percentage of leakage from boiled discs at 4 d after infiltration. Error bars represent se calculated from five biological replicates. The same letter indicates no significant difference between values, and different letters indicate significant differences between values (P < 0.01, nonparametric Kruskal-Wallis test). D, H₂O₂ production in N. benthamiana leaves as determined by DAB staining. N. benthamiana leaves were infiltrated with the corresponding constructs, and the measurement was performed at 2 d after infiltration. E, Specific suppression of PsCRN63 triggered by transient expression of NbCAT1. P. infestans INF1, P. sojae Avh241, and R3a/AVR3a were used in this assay to test the specificity of PCD suppression. Photographs in D and E were taken at 4 d after infiltration. The numbers in each circled area represent summary data showing the number of infiltrated area(s) exhibiting cell death over the total number of leaf areas infiltrated with a particular construct or combination of constructs.