Frischmuth T, Engel M, Lauster S, Jeske H
Biologisches Institut, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Germany.
J Gen Virol. 1997 Oct;78 ( Pt 10):2675-82. doi: 10.1099/0022-1317-78-10-2675.
The nucleotide sequences of two Sida-infecting geminiviruses from Honduras were determined. The symptoms of both viruses are identical in Sida rhombifolia but different in Nicotiana benthamiana. An additional symptom of one virus was yellow vein clearing on infected N. benthamiana leaves. Both Sida golden mosaic viruses (SiGMV-Ho and SiGMV-Ho(yv)) have bipartite genomes (DNAs A and B). From the SiGMV-Ho(yv)-infected S. rhombifolia plant two different DNA B molecules were isolated and cloned. They differ in length by 24 nucleotides [SiGMV-Ho(yv) B1 (2593 nt) and B2 (2569 nt)] and at eight nucleotide positions. Both proteins encoded by DNA B (BV1 and BC1) are affected by these substitutions. Computer analysis shows that the bipartite genomes resemble those of other whitefly-transmitted geminiviruses. From homology analyses we conclude that both viruses are closely related but distinct. Comparison with a Sida-infecting virus from Costa Rica (SiGMV-Co) showed that the two viruses from Honduras are more similar to each other than either of them are to SiGMV-Co. Exchange of SiGMV-Ho and SiGMV-Ho(yv) genomic components resulted in viable pseudorecombinant viruses. SiGMV-Ho DNA A was able to produce a viable pseudorecombinant with SiGMV-Co DNA B while the reciprocal exchange was not infectious in N. benthamiana. SiGMV-Ho(yv) DNA A and SiGMV-Co DNA B produced a viable pseudorecombinant virus whereas only pseudorecombination of SiGMV-Co DNA A with SiGMV-Ho(yv) DNA B2, and not with DNA B1, was infectious in N. benthamiana.
测定了来自洪都拉斯的两种侵染 sida 属植物的双生病毒的核苷酸序列。这两种病毒在菱叶西番莲上症状相同，但在本氏烟草上症状不同。其中一种病毒在感染的本氏烟草叶片上的另一个症状是黄脉褪绿。两种西番莲金色花叶病毒（SiGMV-Ho 和 SiGMV-Ho(yv)）都具有双分体基因组（DNA A 和 DNA B）。从感染 SiGMV-Ho(yv)的菱叶西番莲植株中分离并克隆出两个不同的 DNA B 分子。它们在长度上相差 24 个核苷酸[SiGMV-Ho(yv) B1（2593 个核苷酸）和 B2（2569 个核苷酸）]，且在八个核苷酸位置上存在差异。DNA B 编码的两种蛋白质（BV1 和 BC1）都受到这些替换的影响。计算机分析表明，双分体基因组与其他粉虱传播的双生病毒的基因组相似。通过同源性分析我们得出结论，这两种病毒密切相关但又有所不同。与来自哥斯达黎加的一种侵染 sida 属植物的病毒（SiGMV-Co）比较表明，来自洪都拉斯的这两种病毒彼此之间比它们与 SiGMV-Co 中的任何一种都更相似。SiGMV-Ho 和 SiGMV-Ho(yv)基因组组分的交换产生了有活力的假重组病毒。SiGMV-Ho DNA A 能够与 SiGMV-Co DNA B 产生有活力的假重组体，而反向交换在本氏烟草中没有感染性。SiGMV-Ho(yv) DNA A 和 SiGMV-Co DNA B 产生了有活力的假重组病毒，而只有 SiGMV-Co DNA A 与 SiGMV-Ho(yv) DNA B2（而非 DNA B1）的假重组在本氏烟草中具有感染性。
