Zaim Mohammad, Kumar Yogesh, Hallan Vipin, Zaidi A A
Microbial Technology & Entomology Department, CSIR-Central Institute of Medicinal & Aromatic Plants, P. O. CIMAP, Lucknow, 226015, Uttar Pradesh, India.
Virus Genes. 2011 Aug;43(1):138-46. doi: 10.1007/s11262-011-0610-z. Epub 2011 May 10.
Velvet bean [Mucuna pruriens (L.) DC] is one of the most important medicinal plants. It is used to treat many ailments, but is widely used for the treatment especially for Parkinson's disease because of the presence of 3,4-dihydroxyphenylalanine (L-dopa) in it. It was noticed in last 5 years that the plants in the field showed severe mosaic, downward curling of the leaves, stunting, etc. This is consistently observed over the years in India. The disease was transmitted by whiteflies and by grafting and the causal agent was found to be a bipartite begomovirus. The whole genome was amplified by rolling circle amplification (RCA) using ϕ-29 DNA polymerase and characterized. DNA-A and DNA-B shared a 124-nucleotide (nt) long highly conserved (98%) common region (CR). Comparisons with other begomovirus showed that DNA-A sequence has highest identity (76%) with an isolate of Mungbean yellow mosaic India virus (MYMIV; AY937195) reported from India. This data suggested that the present isolate is a new species of genus Begomovirus for which the name "Velvet bean severe mosaic virus" (VbSMV) is proposed. DNA-B has a maximum sequence identity of 49% with an isolate of Horsegram yellow mosaic virus (HgYMV; AM932426) reported from India. Infectious clones consisting of a 1.7 mer partial tandem repeat of DNA-A and a dimer of DNB-B were constructed and agro-inoculated to Macuna pruriens (L.) DC plants, which showed field observed symptoms 24 days post-infiltration (dpi). In phylogenetic analysis, DNA-A and DNA-B of the present isolate grouped with DNA-A of different begomoviruses reported from fabaceous crops. The study presents first ever molecular evidence of any disease in velvet bean and whole genome analysis of the causative virus which is a distinct bipartite species of Begomovirus.
藜豆[刺毛黧豆（Mucuna pruriens (L.) DC）]是最重要的药用植物之一。它可用于治疗多种疾病，但因其含有3,4 - 二羟基苯丙氨酸（左旋多巴），故而广泛用于治疗尤其是帕金森病。在过去5年中注意到，田间的植株出现严重花叶病、叶片向下卷曲、发育不良等症状。多年来在印度一直持续观察到这种病害。该病害通过粉虱和嫁接传播，并且发现致病因子是一种双分体菜豆金色花叶病毒属病毒。使用ϕ-29 DNA聚合酶通过滚环扩增（RCA）对全基因组进行扩增并进行了特征分析。DNA-A和DNA-B共享一个124个核苷酸（nt）长的高度保守（98%）的共同区域（CR）。与其他菜豆金色花叶病毒属病毒比较表明，DNA-A序列与从印度报道的绿豆黄花叶印度病毒（MYMIV；AY937195）的一个分离株具有最高的同一性（76%）。该数据表明，当前分离株是菜豆金色花叶病毒属的一个新物种，为此提出了“藜豆严重花叶病毒”（VbSMV）这一名称。DNA-B与从印度报道的黑吉豆黄花叶病毒（HgYMV；AM932426）的一个分离株的最大序列同一性为49%。构建了由DNA-A的1.7聚体部分串联重复序列和DNB-B的二聚体组成的感染性克隆，并通过农杆菌接种到刺毛黧豆（Mucuna pruriens (L.) DC）植株上，这些植株在浸润后24天（dpi）出现了田间观察到的症状。在系统发育分析中，当前分离株的DNA-A和DNA-B与从豆科作物报道的不同菜豆金色花叶病毒属病毒的DNA-A归为一类。该研究首次提供了藜豆任何病害的分子证据以及致病病毒的全基因组分析，该病毒是菜豆金色花叶病毒属一个独特的双分体物种。
