Systemic acquired resistance
Systemic acquired resistance (SAR) is a "whole-plant" resistance response that occurs following an earlier localized exposure to a pathogen. SAR is analogous to the innate immune system found in animals, and although there are many shared aspects between the two systems, it is thought to be a result of convergent evolution.[1]
Discovery
The first plant receptors of conserved microbial signatures were identified in rice (XA21, 1995)[2] and in Arabidopsis (FLS2, 2000).[3]
Mechanism
Plants use pattern-recognition receptors to recognize conserved microbial signatures. This recognition triggers an immune response. Plants also carry immune receptors that recognize highly variable pathogen effectors, these include the NBS-LRR class of proteins. SAR is associated with the induction of a wide range of genes (so called PR or "pathogenesis-related" genes), and the activation of SAR requires the accumulation of endogenous salicylic acid (SA). The pathogen-induced SA signal activates a molecular signal transduction pathway that is identified by a gene called NIM1, NPR1 or SAI1 (three names for the same gene) in the model genetic system Arabidopsis thaliana.
See also
References
- Ausubel FM (October 2005). "Are innate immune signaling pathways in plants and animals conserved?". Nature Immunology. 6 (10): 973–9. doi:10.1038/ni1253. PMID 16177805.
- Song WY, Wang GL, Chen LL, Kim HS, Pi LY, Holsten T, Gardner J, Wang B, Zhai WX, Zhu LH, Fauquet C, Ronald P (December 1995). "A receptor kinase-like protein encoded by the rice disease resistance gene, Xa21". Science. 270 (5243): 1804–6. doi:10.1126/science.270.5243.1804. PMID 8525370.
- Gómez-Gómez L, Boller T (June 2000). "FLS2: an LRR receptor-like kinase involved in the perception of the bacterial elicitor flagellin in Arabidopsis". Molecular Cell. 5 (6): 1003–11. doi:10.1016/S1097-2765(00)80265-8. PMID 10911994.
Further reading
- Miller G, Schlauch K, Tam R, Cortes D, Torres MA, Shulaev V, Dangl JL, Mittler R (August 2009). "The plant NADPH oxidase RBOHD mediates rapid systemic signaling in response to diverse stimuli" (PDF). Science Signaling. 2 (84): ra45. doi:10.1126/scisignal.2000448. PMID 19690331.
- Ryals JA, Neuenschwander UH, Willits MG, Molina A, Steiner HY, Hunt MD (October 1996). "Systemic Acquired Resistance". The Plant Cell. 8 (10): 1809–1819. doi:10.1105/tpc.8.10.1809. PMC 161316. PMID 12239363.
External links
- "Exploiting Plants' Protective Proteins". KeyPlex. 2010.