感染柑桔裂皮病类病毒的爪哇三七细胞内的两种闭环RNA

TWO KINDS OF CIRCULAR RNA IN GYNURA AURANTIACA D. C.CELL INFECTED WITH CJTRUS EXOCORTIS VIROID

By two-dimensional electrophoretic technique, a cytoplasmic small circular RNA (cscRNA ) was found in Gynura aurantiaca D.C. leaf. A band similar to that of citrus exocortis viroid ( CEV ) was detected. False result is often caused in detecting CEV in Gynura aurantiaca D.C. by the two-dimensional electrophoretic technique. The result of dot-blotting hyb- ridization, however, showed that there was no detectable sequence homolo-gy between cscRNA and the conserved central region of CEV. Further analysis by polyacrylamide gel electrophoresis ( PAGE ) of nucleic acid that was obtained from the Gynura aurantiaca cell nuclei, revealed no cscRNA in nuclei-rich preparations from healthy Gynura auratiaca D.C.,but CEV was found in nuclei-rich preparations of CEV-infected Gynura auantiaca D.C.. Moreover, the appearance of cscRNA was related with change of seasons, being undetectable in August and September.The above method enables us to avoid spurious result caused by the presence of cscRNA. Therefore, it can be used to diagnose accurately whether Gynura aurantiaca D.C. is infected by CEV or not.