Nucleotide sequence of a cucumber mosaic virus satellite RNA associated with a tomato top stunting

A strain of cucumber mosaic cucumovirus (CMV) belonging to the WT subgroup has been isolated in Apulia (Southern Italy) from tomato plants showing a severe shortening of internodes of terminal shoots leading to a bushy appearance. The disease was clearly distinguishable from other CMV-induced disorders in tomato Italian crops like fruit necrosis, lethal necrosis and shoestring-fern leaf (1). Virus preparations purified from naturally infected plants contained CMV genomic RNAs 1-4 and a satellite RNA named TTS-CARNA 5 (CARNA 5 for CMVassociated RNA 5). The virus, for which the name of CMVTTS was adopted, was cultured in Rutgers tomato and purified by a standardized procedure (2). We report here the nucleotide sequence of its satellite RNA (Figure 1). Nucleotide sequence of TTS-CARNA5 was determined using the dideoxy-chain termination method on both strands of three different pUC-cloned cDNA templates, and by direct sequencing on RNA template (3). When compared with other CMV satellite RNAs (1, Bi, B2, D, E, G, I17N, R, S, WL1, WL2, F, K8) (4, 5, 6) the following nucleotides were found to be uniques f6r TTS-CARNA5: T38 (vs C), C 3 9 (vs. T), A269 (vs G). The 3' half of TTS-CARNA 5 does not contain the 'necrogenic consensus' reported for other CMV satellite RNAs (4). Preliminary results strongly suggest that TTS-CARNA5 is involved in causing tomato top stunting by a modulation of symptoms induced by CMV helper strain.