Articles
MOLECULAR DIVERSITY OF TOSPOVIRUS FROM ARGENTINA: A SUMMARY
Article number
431_23
Pages
261 – 266
Language
Abstract
In this note, we describe advances made in our laboratory on the diversity of Tospovirus in Argentina.
At the beginning of our work in 1992, the Tospovirus genus was thought to be composed of only tomato spotted wilt virus (TSWV) and impatiens necrotic spot virus (INSV) (Law et al. 1991, 1992; de Ávila et al. 1992). At that time, we knew nothing about the presence or absence of different Tospovirus species in Argentina.
We started our work by making a cDNA library of the isolate M316 from Mendoza (Dewey et al. 1995). From the library of about 600 clones, eighteen S RNA-positive clones of variable sizes were detected after hybridization with a probe corresponding to the NSs gene.
The pM316–74 clone (2600 bp in length) showed a positive signal with the oligonucleotide homologous to the 5′ end of the nucleocapsid (N) gene in the viral complimentary strand, which indicates that it covers the entire N-gene sequence.
After sequencing both ends of the clone pM316–74 insert, the length of the insert was determined to be of 2574 bp, and the complete N-gene sequence was established.
Based on nucleotide sequences of the N gene and serological studies, de Avila et al. (1993) defined two additional Tospovirus species, groundnut ringspot virus (GRSV) and tomato chlorotic spot virus (TSCV). In our study, the M316 N gene sequence was aligned and compared with the same region in GRSV, TCSV, TSWV, and INSV. The nucleotide identity and amino acid similarity values indicated that isolate M316 was a GRSV member because it shared the highest identity and similarity percentages (95 and 96%, respectively) with the GRSV N gene.
Later, double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and Western blot confirmed that the M316 isolate belonged to a GRSV member (Dewey et al. 1995). This is the first report of GRSV in Argentina.
At the beginning of our work in 1992, the Tospovirus genus was thought to be composed of only tomato spotted wilt virus (TSWV) and impatiens necrotic spot virus (INSV) (Law et al. 1991, 1992; de Ávila et al. 1992). At that time, we knew nothing about the presence or absence of different Tospovirus species in Argentina.
We started our work by making a cDNA library of the isolate M316 from Mendoza (Dewey et al. 1995). From the library of about 600 clones, eighteen S RNA-positive clones of variable sizes were detected after hybridization with a probe corresponding to the NSs gene.
The pM316–74 clone (2600 bp in length) showed a positive signal with the oligonucleotide homologous to the 5′ end of the nucleocapsid (N) gene in the viral complimentary strand, which indicates that it covers the entire N-gene sequence.
After sequencing both ends of the clone pM316–74 insert, the length of the insert was determined to be of 2574 bp, and the complete N-gene sequence was established.
Based on nucleotide sequences of the N gene and serological studies, de Avila et al. (1993) defined two additional Tospovirus species, groundnut ringspot virus (GRSV) and tomato chlorotic spot virus (TSCV). In our study, the M316 N gene sequence was aligned and compared with the same region in GRSV, TCSV, TSWV, and INSV. The nucleotide identity and amino acid similarity values indicated that isolate M316 was a GRSV member because it shared the highest identity and similarity percentages (95 and 96%, respectively) with the GRSV N gene.
Later, double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and Western blot confirmed that the M316 isolate belonged to a GRSV member (Dewey et al. 1995). This is the first report of GRSV in Argentina.
With the N-gene sequence of the four described species in hand, we selected a pair of genus-specific primers that allowed amplification by reverse transcription polymerase chain reaction (RT-PCR) of a 450-nucleotide fragment of the N gene of fourteen different isolates from several crops and geographical areas of
Authors
R.A. Dewey, L.C. Semorile, O. Grau
Keywords
Online Articles (51)