Expression analysis of CanPIs under induced conditions. [A] RT-PCR amplification (25 cycles) of mRNA from uninduced (UL) and systemic leaf tissues of induced C. annuum infested with aphids (AI), or wounded and treated with water (W+W) or oral secretions (W + OS). Details of primers used are given in Additional file 1: Table S1. cDNA templates were normalized based on 18S rRNA amplification. [B] Abundance of 1-, 2-, 3- and 4-IRD CanPIs upon each induction treatment to C. annuum leaves. Abundance represents the frequency of a specific type of CanPI in the total clones sequenced per induction. The up-regulation of 4-IRD CanPIs in W+OS is evident. [C] Comparison of CanPI expression patterns in C. annuum leaves after different inductions. The Venn diagram presents the number of CanPIs, common or differentially expressed upon each type of induction; AI, W+W or W+OS. W+W showed the highest number of expressed CanPIs. [D] Expression analysis of selected CanPIs in un-induced and systemic leaf tissue of induced C. annuum. The details of gene-specific primers are given in Additional file 1: Table S1.