Caracterização molecular de begomovírus associados a Macroptilium spp. no estado de Alagoas

Abstract

The genus Begomovirus has one or two genomic components, is transmitted by Bemisia tabaci and infects eudicottledonous plants. Bean golden mosaic virus (BGMV) and Macroptilium yellow spot virus (MaYSV) are the most economically important begomoviruses in Brazil, and also infect weed species. Total DNA was extracted individually, from each plant sample, and used as a template for PCR. The viral DNA was cloned and extracted from samples that tested negative for PCR analysis for BGMV and MaYSV species. For cloning, amplification was performed using the rolling circle method. The amplified viral genomes were cleaved with the enzymes PstI and Kpn1, and ligated into a pBluescript KS+ plasmid vector. The resulting samples were transformed into Escherichia coli cells and cultivated in medium with ampicillin. Plasmid DNA was extracted and digested to confirm cloning. Clones were sequenced by Macrogen, Inc. Sequences were aligned and used to create phylogenetic trees. A total of 70 samples were obtained from Macroptilium sp., all of which were PCR positive for the genus Begomovirus. 19 viral isolates were selected to be subjected to the cloning and complete genome sequencing process. Multiple sequence alignments were prepared for the full- length DNA-A, and phylogenetic analyzes were performed. A total of 29 clones corresponding to DNA-A were obtained. Pairwise comparisons indicated the presence of only one species of begomovirus: Macroptilium yellow vein virus (MaYVV) from samples of Macroptilium spp. Bayesian phylogenetic trees showed that MaYVV isolates were structured according to geographic region. The Macroptilium yellow spot virus begomovirus was not detected infecting Macroptilium sp., in the state of Alagoas. Macroptilium yellow vein virus is the predominant begomovirus in Macroptilium spp., in different municipalities in the state of Alagoas, in 2019 and 2020. Phylogenetic analysis showed that MaYVV isolates are geographically structured, with division into four clades and two subgroups.