枇杷果实采后低温贮藏易出现冷害木质化，严重影响果实的商品价值。前期研究表明，枇杷果实木质化过程中果肉不同区域细胞的木质素含量存在差异，但尚不明确木质化过程中积累新合成木质素的主要细胞类型，而这类细胞是引起枇杷果实采后木质化的关键因素，也是木质化调控的靶标细胞。显微技术结合木质素染色、免疫标记等方法只能获得切片时细胞的总木质素分布，无法区分枇杷果实采前原有木质素和采后木质化过程新合成的木质素。本项目拟采用点击化学技术对木质素合成直接前体进行修饰，进而实现枇杷果实采后果肉活细胞新合成木质素在细胞水平的特异性标记，明确新合成木质素细胞的类型和在果实中的分布区域，进一步结合SRS快速显微成像、显微拉曼分子成像、SIM高分辨成像等技术对细胞新合成木质素积累机制开展系统研究，提出枇杷果肉细胞木质素聚合动力学模型，为深入探讨枇杷果实采后木质化机制提供理论支撑，并为调控枇杷果实采后木质化提供细胞靶标。

Chilling injury of lignification is commonly happened when loquat fruit is in postharvest cryopreservation, which affects the fruit’s commercial value seriously. Previous researches show that there are differences in lignin content of cells in different regions of the loquat pulp during lignification. However, the main cell types that accumulate newly synthesized lignin during lignification are not yet known. These cells are the key factors causing postharvest lignification of loquat fruit, and are also the target cells for lignification regulation. Microscopic techniques combined with lignin staining and immunofluorescence labeling can only obtain the distribution of total lignin in the cells at the slicing moment, and it is impossible to distinguish the original lignin in loquat fruit before harvesting and the newly synthesized lignin during the postharvest lignification process. The present project will use the click chemistry technology to modify the direct precursor for lignin synthesis, which will be used to achieve the specific labeling of the newly synthesized lignin in the living cells of the loquat flesh, resulting in identifying the cell type in which the newly synthesized lignin is located and the location of these cells in loquat flesh. Furthermore, SRS microscopic imaging, Raman molecular micro-imaging, and SIM high-resolution imaging techniques will be used to systematically study the accumulation mechanism of newly synthesized lignin in cells. Finally, a kinetic model of lignin synthesis in the cells of loquat flesh will be proposed. The results of the present project will provide theoretical support for further study on lignification mechanism of postharvest loquat fruit, and also provide the target cells for regulating postharvest lignification of loquat fruit.