信号识别是糖类信息物质发挥功能的重要环节，典型植物病原相关分子模式几丁寡糖的受体识别是植物糖生物学领域的热点问题，前期工作揭示含LysM结构域受体激酶LYK在几丁寡糖受体识别过程中发挥重要作用，但忽视了另一类胞外LysM蛋白LysMe。为明确LysMe在几丁寡糖识别过程中作用，在申请人发现一个拟南芥LysMe（AtLysMe3）可强化几丁寡糖信号识别等前期基础上，本项目拟开展实验明确AtLysMe3对几丁寡糖的结合能力与方式；明确AtLysMe与AtCERK1形成受体复合体的机制、结构及对几丁寡糖的响应能力与模式；明确AtLysMe是否是拟南芥对几丁寡糖信号识别过程中行使结合作用的主要元件；进行AtLysMe3-AtCERK1-几丁寡糖多元复合体的晶体结构解析；最终阐明AtLysMe3在几丁寡糖信号识别过程中的作用机制，完善对现有植物几丁寡糖受体系统的认知，加深对糖类信号识别机制的理解。

Perception of extracellular chitin molecule is essential for defense responses in plants, and the recognition interaction between receptor and the phytopathogen-associated molecular pattern, such as chitin oligosaccharides, is a hot topic in the field of plant glycobiology. In the previous report, the important role of Lysine motif receptor kinase (LYK) in the recognition of chitin oligosaccharide-induced signaling has been described. However, the role of another important Lysine motif (LysM) protein-the extracellular lysine motif protein (LysMe) in this process has been overlooked. Primary results from the present study showed that the chitin oligosaccharides-induced signaling can be enhanced by an extracellular Arabidopsis LysMe (AtLysMe3), which may play an important role in recognizing the chitin oligosaccharides-induced signaling. In the present study, the role of AtLysMe3 in the recognition of chitin oligosaccharides in Arabidopsis will be systematically addressed. The binding mechanism of AtLysMe3 to chitin and different degree of polymerization of chitin oligosaccharides will be verified. Furthermore, the interaction between AtLysMe3 and AtCERK1, with or without of chitin, will be investigated. Moreover, the detailed interaction between AtLysMe3, AtCERK1, and chitin oligosaccharides will be studied by crystallography through co-crystallization. These finding will elucidate the role of AtLysMe3 in chitin oligosaccharides-induced signaling, which will contribute to the understanding of chitin recognition system in plants and deepen understanding of the mechanism of carbohydrate signal recognition.