Abstract：
Phytopathogen cell wall polysaccharides have important physiological functions. In this study, we isolated and characterized the alkali-insoluble residue on the inner layers of the Rhizoctonia solani AG1 IA cell wall (RsCW-AIR). Through chemical composition and structural analysis, RsCW-AIR was mainly identified as a complex of chitin/chitosan and glucan (ChCsGC), with glucose and glucosamine were present in a molar ratio of 2.7:1.0. The predominant glycosidic bond linkage of glucan in ChCsGC was β-1,3-linked Glcp, both the α and β-polymorphic forms of chitin were presented in it by IR, XRD, and solid-state NMR, and the ChCsGC exhibited a degree of deacetylation measuring 67.08 %. RsCW-AIR pretreatment effectively reduced the incidence of rice sheath blight, and its induced resistance activity in rice was evaluated, such as inducing a reactive oxygen species (ROS) burst, leading to the accumulation of salicylic acid (SA) and the up-regulation of SA-related gene expression. The recognition of RsCW-AIR in rice is partially dependent on CERK1.
摘要：
植物病原体细胞壁多糖具有重要的生理功能。在这项研究中,我们分离并表征了枯萎病丝核菌AG1IA细胞壁（RsCW-AIR）内层的碱不溶性残留物。通过化学成分和结构分析,RsCW-AIR主要被鉴定为几丁质/壳聚糖和葡聚糖（ChCsGC）的复合物，葡萄糖和葡糖胺以2.7:1.0的摩尔比存在。ChCsGC中葡聚糖的主要糖苷键连接是β-1,3-连接的Glcp，甲壳素的α和β多晶型都通过IR呈现在其中，XRD,和固态核磁共振，ChCsGC显示出67.08%的脱乙酰度。RsCW-AIR预处理有效降低了水稻纹枯病的发病率,并对其在水稻中的诱导抗性活性进行了评价，例如诱导活性氧（ROS）爆发，导致水杨酸（SA）的积累和SA相关基因表达的上调。水稻中RsCW-AIR的识别部分依赖于CERK1。
