Ultrastructural Alteration of Maize Plants Infected with Maize Rough Dwarf Virus

The ultrastructural alteration of maize plants infected with maize rough dwarf virus (MRDV) was studies with transmission electron microscopy. The results revealed that aggregates of the virus particles,the diameter was about 60nm,were found in the root cell, and always distributed near vacuole membrane, but no such particles were checked in the leaves cell. Moreover, the virus was not observed in choroplasts, mitochondria nuclei, plasmodesmata and intercellular canal of all kinds of infected cells of maize. Structures of various organelles changed in leaf and root cells of infected maize. An invard collapse of tonoplast and localized splitting of the tonoplast were observed, the chloroplast structure was destroyed by MRDV, and the number of destroyed or dysplasia chloroplast in leaf cells with serious symptoms were more than that in leaves without symptoms. The matrix of mitochondria in cells infected by MRDV decreased and some of them expanded and destructed. Nucleus was abnormal and nuclear membrane was broken. In addition, infected cells were characterized by a voluminous cytoplasm containing hypertrophied endoplasmic reticulum, a rich ribosome content and a lot of starcn grain.