通过类菌原体ＭＬＯ侵入泡桐筛管，引起寄主细胞变化的观察和对细胞差别透性的分析、病健组织结构的观察，研究了ＭＬＯ侵入泡桐后对寄主组织和细胞的影响。结果表明：ＭＬＯ的侵入使筛管细胞产生胼胝质，胼胝质的聚集堵塞了筛板孔和由胞间连丝连接筛管与相邻细胞的通道，使得皮部细胞的差别透性增大，木质部的差别透性减小，形成层相对厚度变薄。 MLO invades Paulownia sieve, inducing the change of host cells and analyzing the difference of cell permeability, observing the diseased tissue structure, and studying the influence of MLO on the host tissues and cells after invading Paulownia. The results showed that MLO invaded the scaffold cells to produce callose, and the accumulation of callose blocked the scaffold holes and the channels connecting the scaffolds and the adjacent cells by the intercellular connection, which increased the permeability of the dermal cells, The difference in xylem permeability decreases and the relative thickness of the formation layer becomes thinner.