Endoplasmic reticulum remodeling induced by Wheat yellow mosaic virus infection studied by transmission electron microscopy.

Plant virus was a kind of organism lived depending on infecting viable host cell and propagated their posterity by replicating its hereditary nucleotide, transcripting into protein, assembling protein and nucleotide into virion (Ortín and Parra, 2006; Sanfaçon, 2005). Viral infection usually induces remodeling of host cell, especially endoplasmic reticulum (ER) for generating membrane packed viral factory. During the infection of Bymovirus, a kind of membranous body (MB) was generated in host cells, which is thought as an ER aggregate. In present study we performed a study on Wheat yellow mosaic virus (WYMV) induced MB by several transmission electron microscopy (TEM) based methods, including cytological observation, component analysis by immuno-gold labeling and structural analysis by electron tomography (ET). WYMV infection induced at least two morphologies of MB, including the lamella dominated morphology (lamella-MB) looked like sprawling cirrus, and the tubule dominated morphology (tubule-MB) looked like latticed network. MB was verified composing of ER as revealed by immuno-gold labeling by antibody against endoplasmic reticulum (ER) retention signal as well as by detailed observation of MB construction modules as double layer membrane. By immuno-gold labeling, both two MB morphologies (lamella-MB and tubule-MB) had same components in viral derived protein and membrane origination (from ER). Structural analysis by ET reconstruction revealed the organization of ER in MB. Lamella-MB was composed of cesER like structures arranged irregularly whereas tubule-MB was composed of tubER like structures arranged regularly. This study provided insights into the structural details in how Bymovirus utilizing host membrane system.