Zellnig Günther, Pöckl Michael Herbert, Möstl Stefan, Zechmann Bernd
University of Graz, Institute of Plant Physiology, Schubertstrasse 51, A-8010 Graz, Austria.
University of Graz, Institute of Plant Physiology, Schubertstrasse 51, A-8010 Graz, Austria.
J Struct Biol. 2014 May;186(2):245-52. doi: 10.1016/j.jsb.2014.03.006. Epub 2014 Mar 13.
Infection of plants by Zucchini Yellow Mosaic Virus (ZYMV) induces severe ultrastructural changes. The aim of this study was to investigate ultrastructural changes during ZYMV-infection in Cucurbita pepo L. plants on the two and three dimensional (2D and 3D) level and to correlate these changes with the spread of ZYMV throughout the plant by transmission electron microscopy (TEM) and image analysis. This study revealed that after inoculation of the cotyledons ZYMV moved into roots [3 days post inoculation (dpi)], then moved upwards into the stem and apical meristem (5 dpi), then into the first true leaf (7 dpi) and could finally be found in all plant parts (9 dpi). ZYMV-infected cells contained viral inclusion bodies in the form of cylindrical inclusions (CIs). These CIs occurred in four different forms throughout the cytosol of roots and leaves: scrolls and pinwheels when cut transversely and long tubular structures and bundles of filaments when cut longitudinally. 3D reconstruction of ZYMV-infected cells containing scrolls revealed that they form long tubes throughout the cytosol. The majority has a preferred orientation and an average length and width of 3 μm and 120 nm, respectively. Image analysis revealed an increased size of cells and vacuoles (107% and 447%, respectively) in younger ZYMV-infected leaves leading to a similar ratio of cytoplasm to vacuole (about 1:1) in older and younger ZYMV-infected leaves which indicates advanced cell growth in younger tissues. The collected data advances the current knowledge about ZYMV-induced ultrastructural changes in Cucurbita pepo.
西葫芦黄花叶病毒（ZYMV）感染植物会引发严重的超微结构变化。本研究旨在通过透射电子显微镜（TEM）和图像分析，在二维和三维（2D和3D）水平上研究西葫芦植株在ZYMV感染过程中的超微结构变化，并将这些变化与ZYMV在整株植物中的传播情况相关联。本研究表明，接种子叶后，ZYMV在接种后3天进入根部，然后向上移动到茎和顶端分生组织（接种后5天），接着进入第一片真叶（接种后7天），最终在所有植物部位都能检测到（接种后9天）。受ZYMV感染的细胞含有呈柱状内含体（CIs）形式的病毒包涵体。这些CIs在根和叶的细胞质中呈现四种不同形态：横向切割时为卷轴状和风车状，纵向切割时为长管状结构和丝状束。对含有卷轴状内含体的受ZYMV感染细胞进行三维重建显示，它们在整个细胞质中形成长管。大多数卷轴状内含体具有优先取向，平均长度和宽度分别为3μm和120nm。图像分析显示，较年轻的受ZYMV感染叶片中细胞和液泡的大小增加（分别增加107%和447%），导致较老和较年轻的受ZYMV感染叶片中细胞质与液泡的比例相似（约为1:1），这表明较年轻组织中的细胞生长更为活跃。所收集的数据推进了目前关于ZYMV诱导西葫芦超微结构变化的知识。
