Methyl Salicylate Is a Critical Mobile Signal for Plant Systemic Acquired Resistance
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- Sang-Wook Park
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA.
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- Evans Kaimoyo
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA.
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- Dhirendra Kumar
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA.
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- Stephen Mosher
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA.
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- Daniel F. Klessig
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA.
抄録
<jats:p>In plants, the mobile signal for systemic acquired resistance (SAR), an organism-wide state of enhanced defense to subsequent infections, has been elusive. By stimulating immune responses in mosaic tobacco plants created by grafting different genetic backgrounds, we showed that the methyl salicylate (MeSA) esterase activity of salicylic acid–binding protein 2 (SABP2), which converts MeSA into salicylic acid (SA), is required for SAR signal perception in systemic tissue, the tissue that does not receive the primary (initial) infection. Moreover, in plants expressing mutant SABP2 with unregulated MeSA esterase activity in SAR signal–generating, primary infected leaves, SAR was compromised and the associated increase in MeSA levels was suppressed in primary infected leaves, their phloem exudates, and systemic leaves. SAR was also blocked when SA methyl transferase (which converts SA to MeSA) was silenced in primary infected leaves, and MeSA treatment of lower leaves induced SAR in upper untreated leaves. Therefore, we conclude that MeSA is a SAR signal in tobacco.</jats:p>
収録刊行物
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- Science
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Science 318 (5847), 113-116, 2007-10-05
American Association for the Advancement of Science (AAAS)