ENDOSYMBIOTIC BACTERIA ASSOCIATED WITH CIRCULATIVE TRANSMISSION OF POTATO LEAFROLL VIRUS BY MYZUS-PERSICAE
ENDOSYMBIOTIC BACTERIA ASSOCIATED WITH CIRCULATIVE TRANSMISSION OF POTATO LEAFROLL VIRUS BY MYZUS-PERSICAE
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DOI：
10.1099/0022-1317-75-10-2559
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发表时间：
1994-10-01
影响因子：
3.8
通讯作者：
VANDERWILK, F
中科院分区：
文献类型：
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作者：
VANDENHEUVEL, JFJM;VERBEEK, M;VANDERWILK, F
为了了解蚜虫循环传播马铃薯卷叶病毒（PLRV）的分子机制，我们使用蛋白质印迹的病毒重叠测定筛选了桃蚜蛋白作为推定的PLRV结合分子。通过这种方式，我们发现纯化的 PLRV 颗粒对五种蚜虫蛋白表现出亲和力。最容易检测到的一种 M(r) 为 63K，被鉴定为共生素。这是由蚜虫的细菌内共生体合成的主要蛋白质，并释放到血淋巴中。由于进一步的研究清楚地表明 PLRV 颗粒也与天然共生素结合，因此可以设想，当病毒颗粒进入蚜虫的血腔时，会与共生素相互作用。在获得 PLRV 之前，通过用含抗生素的人工饲料喂养桃蚜若虫来抑制原核蛋白合成，可将病毒传播减少 70% 以上。经抗生素处理的蚜虫发现病毒的主要外壳蛋白被降解；这显然会导致病毒 RNA 暴露于酶分解的情况增加，并随之丧失感染性。由于这些原因，我们得出结论，内共生细菌在确定蚜虫血淋巴中 PLRV 的持久性方面发挥着至关重要的作用，而共生素可能是这种相互作用中的关键蛋白质。
In order to understand the molecular mechanisms underlying circulative transmission of potato leafroll virus (PLRV) by aphids, we screened Myzus persicae proteins as putative PLRV binding molecules using a virus overlay assay of protein blots. In this way, we found that purified PLRV particles exhibited affinity for five aphid proteins. The one most readily detected has an M(r) of 63K, and was identified as symbionin. This is the predominant protein synthesized by the bacterial endosymbiont of the aphid and is released into the haemolymph. Since further studies clearly showed that PLRV particles also bind to native symbionin, it was envisaged that virus particles when acquired into the haemocoel of an aphid interact with symbionin. Inhibition of prokaryotic protein synthesis by feeding M. persicae nymphs on an antibiotic-containing artificial diet prior to PLRV acquisition reduced virus transmission by more than 70 %. The major coat protein of the virus was found to be degraded in the antibiotic-treated aphids; this would obviously have resulted in an increased exposure of viral RNA to enzymic breakdown and concomitant loss of infectivity. For these reasons we conclude that endosymbiotic bacteria play a crucial role in determining the persistent nature of PLRV in the aphid haemolymph and that symbionin is probably the key protein in this interaction.