黄瓜花叶病毒单克隆抗体的制备及其对株系特异性的研究

黄瓜花叶病毒CMV-Ca分离株免疫的BALB/c小鼠,取脾淋巴细胞与小鼠骨髓瘤SP2/0细胞融合,筛选分离出杂交瘤细胞3A2,回接小鼠所得到的腹水中单克隆抗体,经酶联免疫吸附试验(ELISA)测得效价为1:2.5×10~6。在琼脂双扩散及免疫电泳反应中与同源抗原CMV-Ca产生沉淀线,与黄瓜花叶病毒其它分离株CMV-p,CMV-Cul,CMV-m不起反应。在ELISA试验中与同源抗原反应强烈,只有在病毒浓度很高时才与其他几个分离株起反应,但反应很弱。最后讨论了株系变异可能是部分改变了抗原决定簇的组份或结构以及单克隆抗体用作探针检查这些变异的可能性。     

IDENTIFICATION OF A RICKETTSIA-LIKE ORGANISM AND ITS INTERCELLULAR MOVEMENT IN SYSTEMATICALLY INFECTED WHEAT PLANT

According to the electron microscopic observation the wheat yellow curl-leaf disease wascaused by a rickettsia-like organism (RLO). The morphology and structure of the pathogenand its distribution within the host plant were of typical characteristics of the RLO. RLO_Swere seen in the phloem and xylem of the host plant. In xylem elements RLO particleswere closely related to electron-dense materials spreading in them. Some channels wereformed in the cell walls of protoxylem, and sometimes in the cell walls of mature xylem ele-ments which were eroded. RLOs entered adjacent cells and intercellular spaces via thesechannels. A large number of RLOs were seen in sieve elements and they could get intoadjacent sieve elements via sieve pores. The places of intercellular movement of RLOs weremostly in the plasmodesmata-dense areas or pit fields where the primary cell walls amongplasmodesmata were dissolved to form some channels by the invasion of RLOs. And theforming of less intercellular channels did not relate to plasmodesmata and pit fields. Basedon these results the mechanism of systematical infection of host plant caused by the RLO isdiscussed in this paper.     

类立克次氏体的鉴定及其在系统感染小麦植株中的胞间转移

本文论述经电子显微镜观察、诊断后证明,小麦黄化卷叶病系类立克次氏体(RLO)侵染所致。病原物的形态结构及其在寄主植株内的分布具有典型的类立克次氏体特征。在寄主维管束的韧皮部、木质部均能见到RLO。导管中RLO颗粒与一些弥漫于导管中的电子致密物质关系密切,经常可见原木质部的管壁,有时是成熟的导管壁受到腐蚀而形成孔道,RLO可经这些孔道进入相邻细胞和细胞间隙。筛管中可见大量RLO,它们可以经过筛孔进入另一筛分子。RLO穿越细胞壁的位置大多在胞间连丝密集区,或纹孔区。这些地方连丝间的次生壁因RLO的侵染而消融形成孔道。少数胞间孔道与胞间连丝或纹孔无关。基于上述观察结果,对该病原物造成寄主系统感染的机制进行了讨论。