Figure 10.

Dynamic and Differential Contributions of PAD4 and SID2 and Their Interactions in Response to flg22, Virulent Pto DC3000, and Avirulent Pto AvrRpt2.

(A) Scheme of three hypothetical scenarios in signaling allocation analysis of genes whose expression levels are higher in Col-0 than in pad4 sid2. If the functions of PAD4 and SID2 depend completely on each other (synergistic), the signaling allocation is PAD4 = 0 (black), SID2 = 0 (black), and PAD4:SID2 = 2 (magenta). If PAD4 and SID2 act additively and independently (no interaction), the signaling allocation is PAD4 = 1 (magenta), SID2 = 1 (magenta), and PAD4:SID2 = 0 (black). If PAD4 and SID2 fully compensate the loss of the other (redundant), the signaling allocation is PAD4 = 2 (magenta), SID2 = 2 (magenta), and PAD4:SID2 = −2 (green). Thus, positive and negative interaction values are indicative of synergistic and redundant relationships between PAD4 and SID2, respectively. Genes whose expression levels are lower in the wild type than in pad4 sid2 are expected to show the opposite signaling allocation patterns.

(B) Genes that commonly show significant transcriptional responses to flg22, Pto DC3000, and Pto AvrRpt2 in Col-0 (q < 0.01 and |log₂FC| > 1) and show significantly higher or lower expression in Col-0 than in pad4 sid2 (q < 0.01 and |log₂FC| > 1) were selected. The selected 193 genes were subjected to signaling allocation analysis and the statistically significant effects (q < 0.01) were visualized by heat maps (magenta-green). The gene induction and suppression levels in Col-0 are also shown (yellow-blue).