Fig. 4.

StLRPK1 positively regulates late blight resistance in potato. (A) Representative images of detached leaves of transgenic potato cv. ‘E-potato-3’ (E3) overexpressing (OE) or RNAi StLRPK1, and E3 and EV (35S:GUS transformant) controls infected with P. infestans and photographed at 5 dpi. The lower images are of leaves stained with trypan blue. (B) Average P. infestans lesion area (mm²) at inoculation sites on OE lines, RNAi lines, and E3 and EV controls measured at 5 dpi. Leaves were detached from 8-week-old potato plants and inoculated with suspensions of sporangia of P. infestans isolates HB09-21 and HB09-14-2 (10⁵ sporangia ml⁻¹) separately. The total number of samples per line involved more than 60 leaves combined with three or four replicates from four plants of each line. Values labeled with different letters are statistically different by one-way ANOVA using pairwise multiple comparison procedures with the Holm–Sidak method (P<0.05); error bars show ±SD. (C) Representative image of P. infestans lesions development (left) and dynamic growth of the pathogen biomass (right) at infected sites on leaves of OE and RNAi lines, and E3 and EV controls, from 1 to 4 dpi. Biomass was calculated at infected sites using qRT-PCR. Error bars represent ±SE. Three biological replicates were performed, each combining five inoculation sites.