Publications (2)16.87 Total impact
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Article: Loss-of-function mutation of REDUCED WALL ACETYLATION2 in Arabidopsis leads to reduced cell wall acetylation and increased resistance to Botrytis cinerea.
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ABSTRACT: Nearly all polysaccharides in plant cell walls are O-acetylated, including the various pectic polysaccharides and the hemicelluloses xylan, mannan, and xyloglucan. However, the enzymes involved in the polysaccharide acetylation have not been identified. While the role of polysaccharide acetylation in vivo is unclear, it is known to reduce biofuel yield from lignocellulosic biomass by the inhibition of microorganisms used for fermentation. We have analyzed four Arabidopsis (Arabidopsis thaliana) homologs of the protein Cas1p known to be involved in polysaccharide O-acetylation in Cryptococcus neoformans. Loss-of-function mutants in one of the genes, designated REDUCED WALL ACETYLATION2 (RWA2), had decreased levels of acetylated cell wall polymers. Cell wall material isolated from mutant leaves and treated with alkali released about 20% lower amounts of acetic acid when compared with the wild type. The same level of acetate deficiency was found in several pectic polymers and in xyloglucan. Thus, the rwa2 mutations affect different polymers to the same extent. There were no obvious morphological or growth differences observed between the wild type and rwa2 mutants. However, both alleles of rwa2 displayed increased tolerance toward the necrotrophic fungal pathogen Botrytis cinerea.Plant physiology 01/2011; 155(3):1068-78. · 6.53 Impact Factor -
Article: Host-pathogen warfare at the plant cell wall.
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ABSTRACT: Plants have evolved sensory mechanisms to detect pathogen attack and trigger signalling pathways that induce rapid defence responses. These mechanisms include not only direct detection of pathogen-derived elicitors (e.g. pathogen-associated molecular patterns (PAMPs) and avirulence factors or effectors) but also indirect sensing of pathogens' impact on the host plant. Among the first plant barriers to pathogen ingress are the cell wall and the cuticle. For those pathogens that penetrate the plant cell wall to gain access to water and nutrients of the plant protoplast, small wounds at penetration sites are created by enzymatic or physical disruption of the plant cell wall. Thus, cell wall integrity sensing is one mechanism by which plants may detect pathogen attack. Some plant cell wall fragments, notably oligogalacturonic acids, elicit similar defence responses in plants as the non-specific PAMP elicitors (e.g. production of reactive oxygen species, elevated expression of defence-associated genes), suggesting that PAMP signalling may provide a good model for studying cell wall integrity sensing in plants. However, much remains to be discovered about this sensing mechanism.Current opinion in plant biology 08/2009; 12(4):406-13. · 10.33 Impact Factor
