Ultrastructural observation related to cell-to-cell movement and long-distance systemic transport on the hosts infected with BBWV 2
与蚕豆萎蔫病毒2号胞间运动和长距离转运相关的寄主细胞超微结构研究

The alteration of ultrastructure in Pisum sativum and Vicia faba leaf cells infected with B935 isolate of BBWV 2 were investigated by electron microscopy,immunogold-labeling technique.The results showed that the membranous proliferation,virus-formed crystals and tubular structures were found in leaf cells of two hosts.At early stages of infection,the tubules containing virus-like particles associate with plasmodesmata in mesophyll cell.Immunogold particles anti-BBWV 2 were localized to the plasmodesmata modified by tubules passing through them.The membranous proliferation and virus-formed tubules were also found in the parenchyma cells,companion cells and transfer cells of vascular bundle.Some virus-like particles located within sieve tube can be labeled immunogold particles anti-BBWV 2.These suggest that BBWV 2,similar CPMV,produce tubules extending into the plasmodesmata.Virions assembled in the cytoplasm are escorted to the tubular structures through interactions with their MP and are then transported to the adjacent cell.Many 160nm in diameter virus-formed tubules in the cytoplasm,as a special aggregate,not directly relate to cell-to-cell movement;Intact virions are long-distance sustemic transported possibly through sieve elements.