Loss-of-Function Mutation of REDUCED WALL ACETYLATION2 in Arabidopsis Leads to Reduced Cell Wall Acetylation and Increased Resistance to Botrytis cinerea
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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DOI：
10.1104/pp.110.168989
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发表时间：
2011-03-01
期刊：
影响因子：
7.4
通讯作者：
Scheller, Henrik Vibe
中科院分区：
文献类型：
--
作者：
Manabe, Yuzuki;Nafisi, Majse;Scheller, Henrik Vibe
植物细胞壁中几乎所有的多糖都是O-乙酰化的，包括各种果胶多糖和半纤维素木聚糖、甘露聚糖和木葡聚糖。然而，参与多糖乙酰化的酶尚未被鉴定。虽然多糖乙酰化在体内的作用尚不清楚，但已知通过抑制用于发酵的微生物来降低来自木质纤维素生物质的生物燃料产率。我们已经分析了四个拟南芥（拟南芥）同源蛋白Cas 1 p已知参与多糖O-乙酰化的新型隐球菌。其中一个基因的功能丧失突变体，命名为减少壁乙酰化2（RWA 2），乙酰化细胞壁聚合物的水平降低。从突变体叶片中分离的细胞壁材料用碱处理释放的乙酸量比野生型低约20%。在几种果胶聚合物和木葡聚糖中发现相同水平的乙酸盐缺乏。因此，rwa 2突变以相同的程度影响不同的聚合物。在野生型和rwa 2突变体之间没有观察到明显的形态学或生长差异。然而，这两个等位基因的rwa 2表现出增加对坏死营养型真菌病原体灰葡萄孢的耐受性。
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.