Construction of a stable and highly infectious intron-containing cDNA clone of plum pox potyvirus and its use to infect plants by particle bombardment.

An infectious plum pox potyvirus cDNA clone was constructed placing a copy of the full-length sequence of the virus genome between an enhanced cauliflower mosaic virus 35S promoter and a nopaline synthase termination signal. Stabilization of the clone and faster growth of bacteria, in addition to higher plasmid yield, followed a modification consisting of the insertion of an intron which interrupted the viral open reading frame at the P3 region. This intron-containing clone was infectious when inoculated into plants after undergoing in vivo transcription and splicing. Particle bombardment delivery of the cDNA greatly increased the efficiency of plant infection.