玉米根冠中类外连丝的结构特征及其共质传输功能(简报)

THE STRUCTURAL CHARACTERISTICS AND SYMPLASTIC TRANSPORT FUNCTION OF THE ECTODESMATA-LIKE OF ROOT CAP TISSUE IN ZEA MAYS

胞间连丝是植物体内连接两个相邻细胞原生质体的共质运输通道，在胞间物质的转运和通讯联络上发挥重要作用。胞间连丝的功能在生理上主要体现在它对胞间转运物质的通透性（permeability），通透性的变化和调节影响到许多生理过程的进展与协调。在植物的不同组织及其发育的不同阶段，不同的物化因素，不同的逆境胁迫以及病原物的侵染均可导致胞间连丝的通透性呈现相应的变动。胞间连丝存在形式的多样性以及对其不同程度和不同方式的修饰，均可对胞间连丝的生理功能及其通透性有明显的影响。

The ultrastructure and symplastic transport function of Ectodesmata-like （ED-like） of the root cap cells of Zea mays, during the detaching stage,were reported by using fluorescence and electron microscopy. It was described the process that plasmodesmata （PD） were gradually stretched and changed into ED-like. It was discovered that the diameter of appressed endoplasmic reticulum （AER） in PD became thinner while the ED-like still remained some structures of PD. By using fluorescence probe incubating, 457Da Lucifer Yellow （LYCH） which was impermeable to the membrane, could enter the root cap cells through ED-like. The results proved that ED-like still retained physiological ac- tivity and kept the symplastic transport function during a period time. When the root tissues were pretreated by cytochalasin D （CD）, Phalloidin and 2,3-butanedione, 2-monoxime （BDM） and then combined with fluorescence probe detecting, the results showed that F-actin and myosin might take part in the regulation of the substance translocation of the ED-like.