Bemisia tabaci transmission of specific Lettuce infectious yellows virus genotypes derived from in vitro synthesized transcript-inoculated protoplasts.

Bemisia tabaci transmission was demonstrated for virions derived from cloned infectious cDNAs of Lettuce infectious yellows virus (LIYV). RNA transcripts synthesized from the cDNA clone of LIYV RNA 1 and for clones of seven genotypes (pR6, p1-1a, p1-2b, p1-2f, p1-4h, p1-5b, and p1-5d) of LIYV RNA 2 produced virions or virion-like particles (VLPs) when inoculated to tobacco protoplasts. pR6, p1-1a, and p1-2f virions were transmissible to plants by B. tabaci and transmission frequencies ranged from 15 to 80%, depending on the virion concentration. In contrast, no transmission was observed for p1-5b VLPs even though their concentrations were comparable to that of transmissible virions. p1-5b VLPs also differed from transmissible virions by the absence of an intact CPm, and this correlated with an out-of-frame stop codon mutation in the CPm gene. This is the first report of the vector transmissibility of infectious cDNAs-derived virions for a virus in the genus Crinivirus.