Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, São Paulo, Brazil.
Essays Biochem. 2023 Apr 18;67(3):455-470. doi: 10.1042/EBC20220128.
Xanthomonas plant pathogens can infect hundreds of agricultural plants. These bacteria exploit sophisticated molecular strategies based on multiple secretion systems and their associated virulence factors to overcome the plant defenses, including the physical barrier imposed by the plant cell walls and the innate immune system. Xanthomonads are equipped with a broad and diverse repertoire of Carbohydrate-Active enZymes (CAZymes), which besides enabling the utilization of complex plant carbohydrates as carbon and energy source, can also play pivotal roles in virulence and bacterial lifestyle in the host. CAZymes in xanthomonads are often organized in multienzymatic systems similar to the Polysaccharide Utilization Loci (PUL) from Bacteroidetes known as CUT systems (from Carbohydrate Utilization systems associated with TonB-dependent transporters). Xanthomonas bacteria are also recognized to synthesize distinct exopolysaccharides including xanthan gum and untapped exopolysaccharides associated with biofilm formation. Here, we summarize the current knowledge on the multifaceted roles of CAZymes in xanthomonads, connecting their function with pathogenicity and tissue specificity.
黄单胞菌病原体可感染数百种农作物。这些细菌利用多种分泌系统及其相关毒力因子，采用复杂的分子策略来克服植物防御，包括植物细胞壁和先天免疫系统构成的物理屏障。黄单胞菌拥有广泛而多样的碳水化合物活性酶（CAZymes），除了能够利用复杂的植物碳水化合物作为碳源和能源外，还在毒力和细菌在宿主中的生活方式中发挥关键作用。黄单胞菌中的 CAZymes 通常组织在类似于多酶系统中，类似于熟知的拟杆菌门多糖利用基因座（PUL）的 CUT 系统（与依赖 TonB 的转运蛋白相关的碳水化合物利用系统）。人们还发现，黄单胞菌能够合成独特的胞外多糖，包括 xanthan 胶和与生物膜形成相关的未开发的胞外多糖。在这里，我们总结了 CAZymes 在黄单胞菌中的多方面作用的最新知识，将其功能与致病性和组织特异性联系起来。
