Figure 4.

Increased Disease Susceptibility to a Virulent Strain of P. infestans by Silencing of WRKY8.

(A) Specific gene silencing of WRKY8 in TRV:WRKY8-infected plants. Silencing of WRKY8 was monitored by qRT-PCR using specific primers. WRKY7, which shows high homology to WRKY8 (see Supplemental Figure 1B online), was used as a silencing control. Data are means ± sd from three independent experiments.

(B) Susceptibility to P. infestans in silenced plants. Photographs were taken 5 d after the inoculation.

(C) Effects of infection of TRV:WRKY8 (8) or TRV:SIPK/WIPK (S/W) on P. infestans infection. Biomasses were determined by qPCR 5 d after inoculation. Data are means ± sd from three independent experiments.

(D) Susceptibility to C. orbiculare in silenced plants. Photographs were taken 5 d after the inoculation.

(E) Effects of infection of TRV:8 or TRV:S/W on C. orbiculare infection. The number of disease spots in the leaves was counted 5 d after the inoculation. Data are means ± sd from four independent experiments.

*P < 0.05 and **P < 0.01; two-tailed Student’s t test.