Banca de DEFESA: ADSO LEVI SOARES DE FIGUEIREDO MENDES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ADSO LEVI SOARES DE FIGUEIREDO MENDES
DATE: 22/06/2023
TIME: 14:00
LOCAL: Defesa online
TITLE:

Molecular characterization and development of a loop-mediated isothermal amplification (LAMP) assay for rapid diagnosis of a new badnavirus associated with air yam (Dioscorea bulbifera L.). 

KEY WORDS:

Dioscorea, dioscorea bacilliform viruses, Caulimoviridae, Dioscoreaceae

PAGES: 55
BIG AREA: Multidisciplinar
AREA: Biotecnologia
SUMMARY:

Yams (Dioscorea spp.) are important staple crops cultivated worldwide, and air yam (Dioscorea bulbifera) is among the 12 commercially grown species. The productivity and safe germplasm exchange of Dioscorea spp. are hindered by several pests and diseases, and viruses pose a significant threat especially due to the vegetative propagation of yams that propitiate viral accumulation and dissemination. At least eight viral families have been reported infecting yams. The family Caulimoviridae comprises 11 genera, of which Badnavirus is widespread wherever yams are planted, and badnaviral transmission occurs mainly by vegetative propagation and different species of mealybugs. A putative new badnavirus has been recently reported in D. bulbifera plants in Brazil, and tentatively named as dioscorea bacilliform BL virus (DBBLV), but only partial sequences of the reverse transcriptase (RT) and ribonuclease H (RNase H) genomic region have been characterized. To recover the complete genome sequence of DBBLV isolates, total DNA obtained from an DBBLV-infected air yam plant was used as template for enrichment of viral circular DNA via rolling circle amplification and subjected to high-throughput Illumina sequencing. Two complete badnavirus-like genomes of 7,196 (DBBLV-DBH1) and 7,342 (DBBLV-DBH3) bp in size were de novo assembled from 1,273,444 and 539,840 reads and a coverage depth of 177 and 74x, respectively. Both isolates belong to the species novel Dioscorea bacilliform BL virus, sharing ≥88% nucleotide identity with at least one isolate of DBBLV deposited in GenBank. The recombination analysis showed a complex interspecies recombination pattern involving the DBBLV-DBH1 and DBBLV-DBH3 isolates as putative recombinant or parental sequences in four independent recombination events. The Bayesian phylogenetic tree reconstructed based on complete genome and RT-RNase H nucleotide sequences showed the new DBBLV isolates were more closely related to dioscorea bacilliform AL virus (DBALV) sequences, but some topological incongruences were observed between these two trees, probably caused by recombination.

BANKING MEMBERS:
Presidente - 1369412 - GAUS SILVESTRE DE ANDRADE LIMA
Interno(a) - 1119939 - ANTONIO EUZEBIO GOULART SANTANA
Interno(a) - 1358530 - MAGNA SUZANA ALEXANDRE MOREIRA
Externo(a) ao Programa - 2149632 - SARAH JACQUELINE CAVALCANTI DA SILVA
Externo(a) à Instituição - PAULO ROBERTO GAGLIARDI
Externo(a) à Instituição - ROBERTO RAMOS SOBRINHO