植物细胞壁主要由多糖聚合物组成,包括纤维素,半纤维素(木葡聚糖,木聚糖,甘露聚糖,和混合键β-1,3/1,4-葡聚糖),还有果胶.在这些细胞壁多糖中,木葡聚糖,木聚糖,甘露聚糖,果胶通常是O-乙酰化的,多糖O-乙酰化在细胞壁组装和抗病中起着重要作用。遗传和生化分析涉及三组蛋白质参与植物细胞壁多糖O-乙酰化:毛状体双折射样(TBL)/未知功能结构域231(DUF231),减少壁乙酰化(RWA),和改变木葡聚糖9(AXY9)。尽管RWA和AXY9的确切作用尚未确定,已发现TBL/DUF231家族的成员是负责木葡聚糖O-乙酰化的O-乙酰转移酶,木聚糖,甘露聚糖,还有果胶.这里,我们全面概述了O-乙酰化细胞壁多糖的发生,生化特性,结构特征,细胞壁多糖O-乙酰转移酶的进化,以及细胞壁多糖乙酰化操作的潜在生物技术应用。进一步深入研究细胞壁多糖O-乙酰化的生化机制,不仅能丰富我们对细胞壁生物学的认识,而且在工程植物中也具有重要意义,这些植物具有增强的抗病性和减少的生物燃料生产的顽抗性。
Plant cell walls are largely composed of polysaccharide polymers, including cellulose, hemicelluloses (xyloglucan,
xylan, mannan, and mixed-linkage β-1,3/1,4-glucan), and pectins. Among these cell wall polysaccharides, xyloglucan,
xylan, mannan, and pectins are often O-acetylated, and polysaccharide O-acetylation plays important roles in cell wall assembly and disease resistance. Genetic and biochemical analyses have implicated the involvement of three groups of proteins in plant cell wall polysaccharide O-acetylation: trichome birefringence-like (TBL)/domain of unknown function 231 (DUF231), reduced wall acetylation (RWA), and altered xyloglucan 9 (AXY9). Although the exact roles of RWAs and AXY9 are yet to be identified, members of the TBL/DUF231 family have been found to be O-acetyltransferases responsible for the O-acetylation of xyloglucan,
xylan, mannan, and pectins. Here, we provide a comprehensive overview of the occurrence of O-acetylated cell wall polysaccharides, the biochemical properties, structural features, and evolution of cell wall polysaccharide O-acetyltransferases, and the potential biotechnological applications of manipulations of cell wall polysaccharide acetylation. Further in-depth studies of the biochemical mechanisms of cell wall polysaccharide O-acetylation will not only enrich our understanding of cell wall biology, but also have important implications in engineering plants with increased disease resistance and reduced recalcitrance for biofuel production.