Loss of a callose synthase results in salicylic acid-dependent disease resistance.

Abstract

Plants attacked by pathogens rapidly deposit callose, a beta-1,3-glucan, at wound sites. Traditionally, this deposition is thought to reinforce the cell wall and is regarded as a defense response. Surprisingly, here we found that powdery mildew resistant 4 (pmr4), a mutant lacking pathogen-induced callose, became resistant to pathogens, rather than more susceptible. This resistance was due to mutation of a callose synthase, resulting in a loss of the induced callose response. Double-mutant analysis indicated that blocking the salicylic acid (SA) defense signaling pathway was sufficient to restore susceptibility to pmr4 mutants. Thus, callose or callose synthase negatively regulates the SA pathway.

• Authors: Marc T Nishimura, Monica Stein, Bi-Huei Hou, John P Vogel, Herb Edwards, Shauna C Somerville
• Journal: Science (New York, N.Y.) (Science) Vol. 301 Issue 5635 Pg. 969-72 (Aug 15 2003) ISSN: 1095-9203 [Electronic] United States
• PMID: 12920300 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Glucans
• Membrane Proteins
• Schizosaccharomyces pombe Proteins
• callose
• Glucosyltransferases
• 1,3-beta-glucan synthase
• Salicylic Acid

Topics

• Alleles
• Arabidopsis (cytology, genetics, metabolism, microbiology)
• Ascomycota (physiology)
• Cell Death
• Gene Expression Profiling
• Gene Expression Regulation, Plant
• Genes, Plant
• Glucans (metabolism)
• Glucosyltransferases (genetics, metabolism)
• Membrane Proteins
• Mutation
• Oligonucleotide Array Sequence Analysis
• Phenotype
• Plant Diseases
• Plant Leaves (metabolism)
• Salicylic Acid (metabolism)
• Schizosaccharomyces pombe Proteins
• Signal Transduction