Loss-of-Function Mutation of REDUCED WALL ACETYLATION2 in Arabidopsis Leads to Reduced Cell Wall Acetylation and Increased Resistance to Botrytis cinerea

• Published in: Plant physiology (Bethesda) 2011-03, Vol.155 (3), p.1068-1078
• Main Authors: Manabe, Yuzuki, Nafisi, Majse, Verhertbruggen, Yves, Orfila, Caroline, Gille, Sascha, Rautengarten, Carsten, Cherk, Candice, Marcus, Susan E, Somerville, Shauna, Pauly, Markus, Knox, J. Paul, Sakuragi, Yumiko, Scheller, Henrik Vibe
• Format: Article
• Language: English
• Subjects: Acetylation; Adaptation, Physiological; Alleles; Arabidopsis - immunology; Arabidopsis - microbiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; BIOCHEMICAL PROCESSES AND MACROMOLECULAR STRUCTURES; Biofuels; Biological and medical sciences; Botrytis - physiology; Botrytis cinerea; Cell Wall - metabolism; Cell walls; Cryptococcus neoformans; DNA, Bacterial - genetics; Epitopes; Epitopes - immunology; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungal Proteins - chemistry; Gene Expression Profiling; Gene Expression Regulation, Plant; Glucans - metabolism; Immunity, Innate - immunology; Leaves; Mutagenesis, Insertional - genetics; Mutant Proteins - isolation & purification; Mutation - genetics; Pectins - metabolism; Phylogeny; Phytopathology. Animal pests. Plant and forest protection; Plant cells; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Epidermis - cytology; Plant Epidermis - metabolism; Plant physiology and development; Plants; Polysaccharides; Protein Transport; Proteins; Sequence Homology, Amino Acid; Subcellular Fractions - metabolism; Xylans; Xylans - metabolism
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.110.168989

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.