Multigene Sequence Analysis of Aster Yellows Phytoplasma Associated with Primrose Yellows

Primula acaulis (L.) Hill. plants showing stunting, leaf-yellowing and virescence were first discovered in the Czech Republic. Polymerase chain reactions with subsequent restriction fragment length polymorphism analyses and sequencing enabled classification of the detected phytoplasmas into the aster yellows group, ribosomal subgroup 16SrI-B, tufI-B, rpI-B, groELIB-III and SecY-IB subgroups. Phylogeny of the 16S rRNA gene sequences as well as sequence analysis of several chromosomal regions, such as the 16S-23S ribosomal operon, ribosomal proteins, spc ribosomal protein operon, genes for elongation factor EF-Tu, molecular chaperonin large subunit GroEL, immunodominant membrane protein, ribosome recycling factor, urydilate kinase, ATP- and Zn2+-dependent proteases not only confirmed its affiliation with the Candidatus Phytoplasma asteris' species but also enabled its detailed molecular characterization. The less researched regions of phytoplasma genome (amp, adk, hflB, pyrH-frr genes) could be valuable as additional markers for phytoplasma through differentiation especially within the 16SrI-B ribosomal subgroup.