Search

En un estudio realizado durante los años 1999 y 2000, en un vivero de orquídeas ubicado en el Valle Central (Costa Rica), se determinó que el género Potyvirus ocupa el segundo lugar en frecuencia de las infecciones virales detectadas, mediante la prueba de ELISA realizada a 148 plantas de diferentes especies de orquídeas nativas, que mostraban síntomas de posi- ble etiología viral. Durante el año 2002, se evaluaron nuevamente para potyvirus, 33 plantas de orquídeas pertenecientes a nueve géneros, en el vivero men- cionado, de las cuales cinco fueron positivas. En un estudio realizado durante los años 1999 y 2000, en un vivero de orquídeas ubicado en el Valle Central (Costa Rica), se determinó que el género Potyvirus ocupa el segundo lugar en frecuencia de las infecciones virales detectadas, mediante la prueba de ELISA realizada a 148 plantas de diferentes especies de orquídeas nativas, que mostraban síntomas de posi- ble etiología viral. Durante el año 2002, se evaluaron nuevamente para potyvirus, 33 plantas de orquídeas pertenecientes a nueve géneros, en el vivero men- cionado, de las cuales cinco fueron positivas.

Tenuivirus infections are associated with the formation of abundant inclusion bodies and with the accumulation of large quantities of a viral noncapsid protein (NCP) in infected plants. Examination of maize stripe virus and rice hoja blanca virus-infected plant tissues using light, immunofluorescent, and electron microscopy showed that the inclusion bodies induced by the two viruses were very similar. Light microscopy revealed that both induced arrays of ring-like, figure-eight-like, and amorphous inclusions, frequently with a substructure of needle-shaped crystals. Immunofluorescent staining showed that all types of inclusion bodies contained the viral NCP but not the viral N protein, associated to the viral RNA. Electron microscopy revealed abundant amorphous semi-electron-opaque inclusion bodies; these had a fibrillar appearance but also occurred as compact, more electron-dense structures. Filamentous electron-opaque inclusion bodies were also detected. Immunogold labeling of ultrathin sections confirmed that all inclusion bodies included NCP and that none included viral N protein. Examination of purified NCP showed that it can form similar amorphous and crystalline arrays in vitro to the inclusion bodies observed in vivo. We propose that the common presence of NCP in all inclusion bodies implies the existence of a single type of intracellular inclusion body, the different developmental stages of which have previously been considered to be distinct inclusion bodies.