Figure 1.

The PAMP-triggered Ca²⁺ burst is altered in bik1 pbl1 mutants. To normalize expression of the apoaequorin transgene, bik1 pbl1/pMAQ2 was generated by crossing. Leaf discs were harvested from individual 4-week old plants grown on soil in short-day chambers as described previously²⁹ and were floated in 12.5 μM coelenterazine (LUX Innovate) overnight in the dark prior to treatment with 100 nM flg22 (EZBiolab), 100 nM elf18 (EZBiolab), 1 μM AtPep1 (EZBiolab), or 100 μg/mL chitin (Sigma Aldrich). The induced cytosolic Ca²⁺ burst was measured as relative light units (RLU) using a charge-coupled device camera (Photek Ltd.) as described previously.¹⁷ Values are means ± standard deviation (n=8). Experiments were performed at least 3 times with similar results.