感染玉米粗缩病毒后玉米植株的超微结构病变研究

Ultrastructural Alteration of Maize Plants Infected with Maize Rough Dwarf Virus

对接种后感染玉米粗缩病毒 (MRDV)的玉米植株的叶片及侧根超微结构进行了电镜观察。研究结果表明 ,受侵染的玉米叶肉细胞中叶绿体的数量有所减少 ,细胞质丰富 ,细胞器发生了不同程度的病变。液泡膜发生明显内陷 ,随着病情的严重液泡膜内陷加剧 ,呈极度松弛状态 ,局部破裂 ;叶绿体被膜破裂 ,轻者成为一松弛的单膜结构 ,严重者被膜完全消失 ,叶绿体中的片层膜系统消失 ,取而代之的是大量淀粉粒。线粒体及细胞核形态异常 ,随着病害的加重 ,线粒体逐渐肿大 ,基粒缩小 ,膜破裂 ,类囊物流入细胞中 ,细胞膜破裂。在玉米植株的根部细胞中观察到了大量的病毒粒体 ,这些粒体大多集中在细胞壁处形成病毒质体。感病细胞的叶绿体、线粒体、核。

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.