Figure 1.

A schematic depiction of the general mechanism of biotic stress tolerance in plants. When plants are subjected to biotic stress, such as bacterial, viral, and insect infections, signal sensitivity is induced. It activates secondary mediators and regulates hormonal influences, causing transcription factors to be up- or down-regulated. Activated transcription factors will bind to specific promoter region cis-acting elements. The defense-related genes are activated by transcription factors with activation activity, leading to stress tolerance. The activity of defense-related genes is suppressed by transcription factors with repression activity, resulting in susceptibility to stress. ABA—abscisic acid; ET—ethylene; JA—jasmonic acid; SA—salicylic acid; NAC—no apical meristem, Arabidopsis-thaliana-activating factor, cup-shaped cotyledon; MYB—myeloblastosis-related transcription factor; WRKY—WRKY transcription factor; ERF—ethylene-responsive transcription factor; bZIP—basic leucine zipper transcription factor; bHLH—basic helix-loop-helix transcription factor.