Abstract
Systemic disease resistance induced by various stimuli from outside, such as pathogen infection and wounding, are governed by phytohormones like salicylic acid, jasmonic acid, ethylene, and brassinosteroid. These signalings have crosstlaks between each other, even with ABA signaling activated by abiotic stresses. These crosstalks would play an important role in regulation of living systems of plants under various conditions. To control this regulation system by transgenic technology or chemicals would be practically useful.