Figure 1.

Overexpression of SlREM1 decreases the resistance of tomato leaves to B. cinerea and induces cell death in N. benthamiana leaves. A, Lesion development on wild-type (WT) and SlREM1 transgenic tomato leaves infected by B. cinerea (overexpression lines: OE-1, OE-2, and OE-3; RNAi lines: RNAi-1, RNAi-2, and RNAi-3). Data represent means from 24 leaves and the error bars are sd. Asterisks indicate significant differences compared with wild-type plants using ANOVA with a post hoc Tukey’s Honestly Significant Difference test (P < 0.05). B, Disease symptoms at 48 h after inoculation with B. cinerea on wild-type and SlREM1-overexpressing (OE-1, OE-2, and OE-3) tomato leaves. The leaves were digitally extracted for comparison. C, Heterologous expression of 3×Flag-SlREM1 in N. benthamiana leaves triggers cell death. N. benthamiana leaves were infiltrated with A. tumefaciens strain carrying 3×Flag-SlREM1. Cell death symptoms were photographed at 6 dpi. The red circles indicate the infiltration areas. D, Immunoblot analysis for transiently expressed 3×Flag-SlREM1 in N. benthamiana leaves at 2 dpi. Total proteins were isolated from N. benthamiana leaves transiently expressing 3×Flag-SlREM1 and 3×Flag, respectively, followed by immunoblotting using anti-Flag antibody. ACTIN protein level was used as a loading control. E, N. benthamiana leaves transiently expressing 3×Flag and 3×Flag-SlREM1 were stained using trypan blue at 5 dpi. Red circles indicate the infiltration areas. F, Determination of electrolyte leakage from leaf areas transiently expressing 3×Flag and 3×Flag-SlREM1. Data are means and sd of three independent biological replicates. Asterisks indicate significant differences compared with leaves expressing 3×Flag using ANOVA with a post hoc Tukey’s Honestly Significant Difference test (*P < 0.05 and **P < 0.01).