Department of Biology, University of York, YO1 5DD, York, UK.
Planta. 1987 Jun;171(2):145-57. doi: 10.1007/BF00391090.
Various fluorescent molecular probes have been injected into the cytoplasm of nectary trichome cells of Abutilon striatum to ascertain the conductivity of the plasmodesmata. Most of the probes were based on fluorescein conjugated to a range of amino acids and peptides. The probes are not broken down by cytoplasmic enzymes during the period of observation. The results indicate that there are no specific effects of aromatic amino acids, either polar or hydrophobic types, on the conductivity of the Abutilon plasmodesmata, contrary to reports for other plants. The conductivity of the plasmodesmata in the trichomes is slightly greater than for any that have been studied in the tissues of other plants. It is proposed that in Abutilon the mobility of a probe is determined solely by the effective Stokes radius of the molecule, and that the radius of the molecule is governed by the molecular weight and, in particular, by the nature of the side groups in the peptide chain attached to the fluorochrome. Calculations are presented which indicate that channels between material in the plasmodesmatal annulus are the most likely route for the diffusion of the probes, and that the width of individual channels in the annulus is close to 3 nm.
各种荧光分子探针已被注入到 Abutilon striatum 的蜜腺毛状体细胞质中，以确定胞间连丝的传导性。大多数探针基于荧光素与一系列氨基酸和肽的结合。在观察期间，探针不会被细胞质酶分解。结果表明，芳香族氨基酸（无论是极性还是疏水性）对 Abutilon 胞间连丝的传导性没有特定影响，这与其他植物的报告相反。毛状体中胞间连丝的传导性略高于其他植物组织中研究过的任何胞间连丝。有人提出，在 Abutilon 中，探针的迁移率仅由分子的有效斯托克斯半径决定，而分子的半径则由分子量决定，特别是由连接在荧光染料上的肽链的侧基的性质决定。提出了计算结果，表明在胞间连丝环中的物质之间的通道最有可能是探针扩散的途径，并且环中的单个通道的宽度接近 3nm。
