User:Eugene M. Izhikevich/Proposed/Induced systemic resistance
Dr. Corné Pieterse accepted the invitation on 2 February 2009 (self-imposed deadline: 2 August 2009).
Induced systemic resistance (ISR) refers to a state of enhanced defensive capacity developed by a plant when appropriately stimulated. ISR is not the creation of resistance where there is none, but the activation of latent innate immune responses that are expressed upon subsequent, so-called “challenge” inoculation with a pathogen. ISR occurs naturally as a result of colonization of the roots by beneficial soil-borne microorganisms, such as plant-growth promoting rhizobacteria and mycorrhizal fungi. Different beneficial microbe-associated molecular patterns (MAMPs) are recognized by the plant, which results in a mild, but effective activation of the plant immune responses in systemic tissues. Systemic induced resistance can also be triggered upon limited infection by a pathogen, particularly when the plant develops a hypersensitive reaction. This type of systemically induced resistance is often referred to as systemic acquired resistance (SAR). Both ISR and SAR are characterized by the fact that they confer a broad spectrum resistance in systemic tissues against many types of plant pathogens, including viruses, bacteria, fungi, and oomycetes and in some cases even insect herbivores.