Molecular Characterization Of Soybean Mosaic Virus Of Shanxi Glycine Max Isolate And Atractylodes Macrocephala Koidz Isolate

Soybean is an important oil plant and food supply, and it is the main source for edible oil and plant proteins. Atractylodes macrocephala Koidz is a Compositae perennial herbaceous plant. It is one of ten chief exports of traditional Chinese medicines. Recently, soybean and Atractylodes macrocephala Koidz with severe mosaic were found to be infected with some viruses. In order to system identification the viral pathogens, extraction of double-stranded RNA (dsRNA), sequence-independent amplification (SIA) and RT-PCR was used.The results were as follows:Soybean mosaic virus (SMV) was detected in both soybean and Atractylodes macrocephala Koidz, and named them SMV-SX and SMV-Am respectively. The genome was9586nts and10044nts long individually. Wihe the typical features of genus of SMV. Based on comparison with the proposed locations of cleavage of other SMV polyproteins,11mature proteins were predicted, which was P1、 HC-Pro、P3、P3-PIPO、6K1、CI、6K2、NIa-Vpg、NIa-Pro、NIb and CP from the N terminus to C terminus. The putative cleavage sites were V-x-x-Q(orE)/(A,S,G or V), the typical recognize model of this genus. Analysis of the conserved motifs of SMV-SX and SMV-Am showed that they were coincided with those of the SMV, and may had the similar functions. To further characterize SMV-SX and SMV-Am, comparison was made between the CP amino acid sequences of SMV-SX and other eight SMV isolates and the phylogenetic analysis was done.The results idiecated that the homology between all those CP sequences was ruther high. The phylogenetic analysis of amino acid sequences of CP showed that SMV-SX was most closely related to SMV-Y5. The same analysis was done between SMV-Am and other24Potyviruses. The results showed that the homology between all those CP sequences was high. SMV-Am and the other SMV were in the same evolution clusters, but SMV-Am shared farther identities at amino acid level with WMV. Phylogenetic analysis of each amino acid between SMV-Am and the isolate of other P V Y suggested that SMV-Am was recombined between SMV and WMV. Similarity and homology of amino acid sequence for SMV CP genes showed high host and partially geological pertinence, while alignment and comparison of amino acid sequence showed that the host pertinence is largely distinct than gelolgical pertinence.