Spring 2000, Plant Sci. Ross showed TMV and other viruses induced SAR in tobacco. Resistance later shown by others to be induced by many pathogens, -most often those eliciting a necrotic reaction 3.
Resistance can persist for a week to many weeks.
Some reports describe season-long protection after activation of SAR 5. Repertoire of SAR genes varies in different plant species, perhaps due to different pathogen landscapes during the evolution of the plant species 6. N. glutinosa .x. N. debneyi shows 30 times greater SA accumulation than parents, expresses PR genes and is resistant to pathogens 6. D. Synthesis and partitioning control the level of SA 1.