Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-5-29
pubmed:abstractText
The phenylpropanoid-derived natural product salicylic acid (SA) plays a key role in disease resistance. However, SA administered in the absence of a pathogen is a paradoxically weak inductive signal, often requiring concentrations of 0.5 to 5 mM to induce acquired resistance or related defense mechanisms or to precondition signal systems. In contrast, endogenous SA accumulates to concentrations of < 70 microM at the site of attempted infection. Here, we show that although 10 to 100 microM SA had negligible effects when administered to soybean cell suspensions in the absence of a pathogen, physiological concentrations of SA markedly enhanced the induction of defense gene transcripts, H2O2 accumulation, and hypersensitive cell death by an avirulent strain of Pseudomonas syringae pv glycinea, with optimal effects being at approximately 50 microM. SA also synergistically enhanced H2O2 accumulation in response to the protein phosphatase type 2A inhibitor cantharidin in the absence of a pathogen. The synergistic effect of SA was potent, rapid, and insensitive to the protein synthesis inhibitor cycloheximide, and we conclude that SA stimulates an agonist-dependent gain control operating at an early step in the signal pathway for induction of the hypersensitive response. This fine control mechanism differs from previously described time-dependent, inductive coarse control mechanisms for SA action in the absence of a pathogen. Induction of H2O2 accumulation and hypersensitive cell death by avirulent P. s. glycinea was blocked by the phenylpropanoid synthesis inhibitor alpha-aminooxy-beta-phenylpropionic acid, and these responses could be rescued by exogenous SA. Because the agonist-dependent gain control operates at physiological levels of SA, we propose that rapid fine control signal amplification makes an important contribution to SA function in the induction of disease resistance mechanisms.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-1123431, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-11607454, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-11607539, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-11607542, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-1409628, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-1525827, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-1623521, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-16593513, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-16667764, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-17757215, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-17810266, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-2239449, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-2318857, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-2781284, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-2835661, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-7479795, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-7670505, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-7732374, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-7902614, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-7954825, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8033202, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8052628, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8266079, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8335641, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8521516, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8525370, http://linkedlifedata.com/resource/pubmed/commentcorrection/9061956-8692867
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1040-4651
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
261-70
pubmed:dateRevised
2010-9-13
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Salicylic acid potentiates an agonist-dependent gain control that amplifies pathogen signals in the activation of defense mechanisms.
pubmed:affiliation
Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't