Systemic Acquired Resistance and Signal Transduction in Plant

Systemic acquired resistance (SAR), known as broad-spectrum, inducible plant immunity, is a defense response triggered by pathogen infection. The response begins with the recognition of plant resistance (R) with the corresponding avirulence (avr) gene from the pathogen. There are some genes for convergence of signals downstream of different R/avr interacting partners into a single signaling pathway. Salicylic acid (SA) is required for the induction of SAR and involved in transducing the signal in target tissues. The SA signal is transduced through NPR1, a nuclear-localized protein that interacts with transcription factors that are involved in regulating SA-mediated gene expression. Some chemicals that mimic natural signaling compounds can also activate SAR. The application of biochemical activators to agriculture for plant protection is a novel idea for developing green chemical pesticide.