تعیین ترادف کامل ناحیه CP-UTR ، فیلوژنی و شناسایی انواع موتیف در ژنوم ویروس موزائیک معمولی لوبیا

To determine the complete sequence of the CP-UTR region, phylogeny, and motif types in the genome of the Bean common mosaic virus (BCMV) from bean fields around Gorgan showing symptoms such as mosaic, yellowing, and malformation, samples were collected. Viral RNA was extracted from the samples and subjected to RT-PCR. To amplify the coat protein (CP) genome and untranslated region (UTR) of the genome, degenerate primers Oligo1n(F) and Oligo2n(R), designed from other BCMV isolates available in GenBank, were used in the polymerase chain reaction (PCR). The PCR products were sequenced. After sequencing the PCR products, the sequences were compared with existing information in the GenBank database using the NCBI BLAST program, confirming the viral nature of the fragments and their similarity to the BCMV sequences in GenBank. The sequencing results indicated the amplification of a 1122 base pair CP-UTR region, comprising 861 nucleotides from the CP region and 261 nucleotides from the UTR region, consistent with the expected fragment size. The results of this study showed that the highly conserved DAG motif, present in all potyviruses for aphid transmission, was also observed in BCMV-IRAN in the amino region of the coat protein. However, the DAS motif was seen in isolate AF083559 from the USA, and the SAG motif in isolate U37075 from Russia. Additionally, the MVWCIENG motif was present in the central CP region of the Iranian isolate and other studied BCMVs, whereas in the AF045066 isolate from the USA, the D amino acid was in the E position. Furthermore, the phylogenetic tree analysis revealed that all analyzed isolates were classified into five groups. Group one, with the highest number, included a wide range of isolates from Europe, America, and Iran. The CP sequence analysis of BCMV isolates indicated a 99.2% nucleotide similarity between the Iranian isolate and an isolate from Russia, suggesting a close relationship between BCMV in Iran and isolates from different parts of the world. This information could play a significant role in identifying the primary source of evolution for the Iranian isolate. Moreover, a dn/ds ratio of less than one indicated the significant role of negative selection in the diversity and evolution of this virus, suggesting that the main mechanism of BCMV evolution and diversity in Iran has been negative selection.