Figure 1.

Changes in expression during responses of plant samples to pathogens. The plant's reaction to biotic stress involves a few steps: after the initial signal input from the pathogen which is recognized by the related receptors (putative R genes), transcription of the cascade of the plant defence mechanism is triggered, including oxidative stress changes. Inside the cell, signals are transmitted to lead to the production of defence molecules (PR-proteins, heat shock proteins and secondary metabolites). Genes with experimental indication of involvement in the biotic stress are gathered on the main panel (coloured with dark grey), while genes and pathways that are putatively involved in biotic stress pathway are shown on the left and right sides (coloured in light grey). a) Potato samples 30 minutes after inoculation with potato virus Y. b) Tobacco samples 24 hours after inoculation with M. secta. In both cases, the signal after infection is expressed as a ratio relative to the signal in unifected controls, converted to a log₂ scale, and displayed. The scale is shown in the figures.