Integration of Banana Streak Badnavirus into theMusaGenome: Molecular and Cytogenetic Evidence

Abstract

Breeding and tissue culture of certain cultivars of bananas (Musa) have led to high levels of banana streak badnavirus (BSV) infection in progeny from symptomless parents. BSV DNA hybridized to genomic DNA of one such parent, Obino l'Ewai, suggesting integration of viral sequences. Sequencing of clones of Obino l'Ewai genomic DNA revealed an interface between BSV and Musa sequences and a complex BSV integrant. In situ hybridization revealed two different BSV sequence locations in Obino l'Ewai chromosomes and a complex arrangement of BSV and Musa sequences was shown by probing stretched DNA fibers. This is the first report of integrated sequences that possibly lead to a plant pararetrovirus episomal infection by a mechanism differing markedly from animal retroviral systems.

The release of genetically modified crops into the environment

“…It is known that plant viruses can acquire host sequences, but in the case of RNA viruses it would seem highly unlikely that such DNA will become integrated in the genome of a related plant (Tepfer, 1993), although RNA recombination itself may be an HGT issue (Malno et al, 1999). In the case of DNA viruses, there is some evidence for transfer of genetic material from virus to plants (Bejarano et al, 1996;Harper et al, 1999;Jakowitsch et al, 1999). Feeding mice with M13 phage did not exhibit any transformation of potential microbial hosts, but 400-bp M13 DNA fragments could be recovered from faeces, blood and even from cells in offspring developing in female mice (Schubbert et al, 1997;.…”

Development of Real-Time PCR for the Rapid Detection of Episomal Banana streak virus (BSV)

“…In recent years, the virus has caused increasing concern worldwide as infection of new banana hybrids with many desirable traits frequently occurs, curtailing their exploitation. Recent reports indicate that BSV infection may arise from the activation of viral sequences that are integrated into the Musa genome (10,20).…”

“…BSV-OL sequences have been found integrated into the nuclear genome of cv. Obino l'Ewai (AAB group), which is used as a parent for several breeding programs (10,20). One of the characterized integrated sequence represents the full genome of the episomal virus BSV-OL, although the sequence is interspersed with a "scrambled" region containing inverted and noncontiguous viral and non-BSV sequences (20).…”

Detecção e análise da variabilidade de seqüências do Banana streak virus (BSV) em bananeiras no Brasil

“…é uma das fruteiras mais cultivadas nos países tropicais e seus frutos representam a quarta mais importante mercadoria comercializada no mundo (8). O Brasil destaca-se como o segundo produtor mundial (11).O Banana streak virus (BSV) tem se tornado um dos mais importantes vírus em bananeiras e plátanos por ser distribuído em mais de 40 países da África, Ásia, Europa, Oceania e Améri-cas do Sul e Central (10) e pelo fato de evidências indicarem a integração de seqüências do genoma de Musa, causando problema no intercâmbio de germoplasma (6,7,12).O Banana streak virus pertence ao gênero Badnavirus, estando atualmente classificado na família Caulimoviridae (14). …”

“…O Banana streak virus (BSV) tem se tornado um dos mais importantes vírus em bananeiras e plátanos por ser distribuído em mais de 40 países da África, Ásia, Europa, Oceania e Améri-cas do Sul e Central (10) e pelo fato de evidências indicarem a integração de seqüências do genoma de Musa, causando problema no intercâmbio de germoplasma (6,7,12).…”