Partial characterization of a Potyvirus causing mosaic and flower variegation in Catharanthus roseus / Caracterização de um novo Potyvirus causador de mosaico foliar e variegação floral em Catharanthus roseus

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Catharanthus roseus is known as the common periwinkle or Madagascar periwinkle. It is a perennial, evergreen herb in the family Apocynaceae, which was originally native to the island of Madagascar, although both name and classification are contradictory in some literature. The plants grow up to 80 cm high; have glossy, dark green leaves and bloom during summer. The flowers range from white to hot pink to purple. The species has historically been used in popular medicine to treat a wide assortment of human diseases, as it contains more than 150 useful alkaloids. Plants of C. roseus exhibiting mosaic symptoms followed by malformation of the leaf blades and flower variegation were collected from a garden at the University of São Paulo, School of Agriculture (Piracicaba, State of São Paulo, Brazil). Preliminary electron microscopy exams of negatively stained leaf sap revealed that the symptoms were associated with potyvirus-like particles. The objective of the present work was to obtain further biological, immunological and molecular data to better characterize this species of the genus Potyvirus, family Potyviridae. Of 28 plant species from eight botanical families inoculated mechanically with this potyvirus, only C. roseus and Nicotiana benthamiana developed systemic mosaic, whereas Chenopodium amaranticolor and C. quinoa exhibited only chlorotic local lesions. The virus was transmitted by Aphis gossypii and Myzus nicotianae, but not by Toxoptera citricidus. Polyclonal antiserum raised against this potyvirus reacted with the homologous virus, Passion fruit woodiness virus (PWV) and Cowpea aphid borne mosaic virus (CABMV) in PTA-ELISA. The molecular mass of the coat protein (CP) was approximately 34 kDa. RT-PCR from viral RNA amplified a fragment of approximately 1654 nucleotides (nt) at the 3 -terminal of the viral genome, containing portion of the replicase gene (Nib), the entire CP gene and the 3 untranslated region (3 UTR) (286 nt). When the nucleotide sequence of the CP gene was compared with other members of the Potyviridae family, identities varied from 67.0 to 76.0%. The highest identity was with Omphalodes virus Y. Identity of the deduced amino acid of the CP varied from 62.0 to 71.0%, with the highest for East Asian Passiflora virus. For the 3 UTR, identities varied from 16.8 to 28.6%. The name Catharanthus mosaic virus (CatMV) is proposed for this new potyvirus.

ASSUNTO(S)

potyvirus mosaico (doença de planta) catharanthus mosaic virus planta ornamental transmission rt-pcr elisa transmissão de doenças reação em cadeia por polimerase nucleotide sequence seqüência de aminoácidos pta-elisa

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