Systemic acquired resistance signal transduction |
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Authors: | Michelle D. Hunt John A. Ryals Dr. Dieter Reinhardt |
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Affiliation: | 1. Agricultural Biotechnology Research Unit , Ciba‐Geigy Corporation , 3054 Cornwallis Road, Research Triangle Park, NC, 27709;2. Agricultural Biotechnology Research Unit , Ciba‐Geigy Corporation , 3054 Cornwallis Road, P.O. Box 12257, Research Triangle Park, NC, 27709, USA;3. Plant Biology Laboratory , The Salk Institute , 10010 N. Torrey Pines Rd., La Jolla, CA, 92037 |
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Abstract: | Systemic acquired resistance (SAR) is an inducible plant defense response in which a prior foliar pathogen infection activates resistance in noninfected foliar tissues. Salicylic acid (SA) accumulation is essential for the establishment of SAR. While SA is probably not the long‐distance systemic signal instrumental for SAR activation, it is required for transduction of the signal in noninfected tissues. Although SAR was first described as a response to necrogenic pathogen infection, synthetic chemicals have been identified that effectively activate SAR. Elucidation of SAR signal transduction has been facilitated by the identification and characterization of Arabidopsis mutants. Disease lesion mimic mutants exhibit constitutive SAR as well as spontaneous lesion formation similar to pathogen‐associated hypersensitive cell death. Some disease lesion mimic mutants do not exhibit a lesioned phenotype when SA accumulation is prevented, thereby providing evidence for a feedback loop in SAR signal transduction. Moreover, characterization of mutants compromised for SAR activation has provided additional evidence for common signaling components between SAR and gene‐for‐gene resistance. |
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Keywords: | cell death disease resistance hydrogen peroxide hypersensitive response lesions simulating disease mutants pathogenesis‐related proteins salicylic acid signal transduction |
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