A Novel Satellite RNA of Cucumber Mosaic Virus Induces Unique Line-pattern Mosaic Symptoms in Tobacco

The CMV(YW) isola le of cucumber mosaic vi rus (CMV) induced unique line-pattern mosa ic symptoms in systemically infected leaves of tobacco (NicOliullo rabacllm cv. Ky57). By northern hybridizalion a nalysis using cDNA to CMV(y) sa Lellile RNA as a probe, il was confirmed lhat CMV(YW) co ntained a salellile RNA, which was u~signated sa t-YW RNA; this was 388 nuclcolides in length and did not. have either tl conserved domain that induces necrosis in tomato or chlorosis in tobacco. CMV(YW) free of sa l-YW RNA. which was isola led by the single lesion isolation method using Chenopodium (lmarallf;color. did not induce the unique line-pattern mosaic symptom. Furthermore. the sat-YW RNAmediated line-paltern mosaic symptom was also induced by ill I:i, /"o transcribed infectiolls sat-YW RNA in tobaccos infecled wilh either CMV(YW) or CMV(Y) genomic RNA. These resullS clearly demonslrated lhal sal-YW RNA induces the unique line-pattern mosa ic symptom on CMV-infecled lobaccos.