In planta expression of a protein encoded by the extrachromosomal DNA of a phytoplasma and related to geminivirus replication proteins

An extrachromosal DNA, EcOYW1, from onion yellows phytoplasma (OY-W) is reported. The complete nucleotide sequence of EcOYW1 was found. The replicon was shown to encode a homologue of geminivirus replication protein Rep, but not found in OY-M, a mild symptom line derived from OY-W. It appears it may be related to the pathogenicity of OY-W. Plant pathogenic phytoplasmas are prokaryotes lacking cell walls and associated with various plant diseases including some in garland chrysanthemums.