Clover proliferation phytoplasma: ‘Candidatus Phytoplasma trifolii’

Abstract

Clover proliferation phytoplasma (CP R ) is designated as the reference strain for the CP phylogenetic group or subclade, on the basis of molecular analyses of genomic DNA, the 16S rRNA gene and the 16S-23S spacer region. Other strains related to CP R include alfalfa witches'-broom (AWB), brinjal little leaf (BLL), beet leafhopper-transmitted virescence (BLTV), Illinois elm yellows (ILEY), potato witches'-broom (PWB), potato yellows (PY), tomato big bud in California (TBBc) and phytoplasmas from Fragaria multicipita (FM). Phylogenetic analysis of the 16S rRNA gene sequences of BLL, CP R , FM and ILEY, together with sequences from 16 other phytoplasmas that belong to the ash yellows (AshY), jujube witches'-broom (JWB) and elm yellows (EY) groups that were available in GenBank, produced a tree on which these phytoplasmas clearly clustered as a discrete group. Three subgroups have been classified on the basis of sequence homology and the collective RFLP patterns of amplified 16S rRNA genes. AWB, BLTV, PWB and TBBc are assigned to taxonomic subgroup CP-A, FM belongs to subgroup CP-B and BLL and ILEY are assigned to subgroup CP-C. Genetic heterogeneity between different isolates of AWB, CP R and PWB has been observed from heteroduplex mobility assay analysis of amplified 16S rRNA genes and the 16S-23S spacer region. Two unique signature sequences that can be utilized to distinguish the CP group from others were present. On the basis of unique properties of the DNA from clover proliferation phytoplasma, the name 'Candidatus Phytoplasma trifolii' is proposed for the CP group.

‘Candidatus Phytoplasma’, a taxon for the wall-less, non-helical prokaryotes that colonize plant phloem and insects

“…Phytoplasma', identified as described above, and a list of 16S rRNA gene sequences of related strains. The listed taxa either have already been described individually in past issues of IJSEM or are described in accompanying papers in this issue or in forthcoming papers; the reader is referred to the original papers for their detailed descriptions (Zreik et al, 1995;Davis et al, 1997;White et al, 1998;Griffiths et al, 1999;Sawayanagi et al, 1999;Montano et al, 2001;Jung et al, 2002Jung et al, , 2003aHiruki & Wang, 2004;Lee et al, 2004a, b;Marcone et al, 2004a, b;Seemüller & Schneider, 2004 Lee, I.-M., Davis, R. E. & Hiruki, C. (1991). Genetic interrelatedness among clover proliferation mycoplasmalike organisms (MLOs) and other MLOs investigated by nucleic acid hybridization and…”

Automated RFLP pattern comparison and similarity coefficient calculation for rapid delineation of new and distinct phytoplasma 16Sr subgroup lineages

“…It was not until the mid-1970s that the aetiological agent of the disease was determined to be a phytoplasma (Hiruki & Wang, 2004). Since then, many emerging and previously unknown diseases have been found to be associated with infection by various phytoplasma strains of the clover proliferation group (16SrVI).…”

The first detection of ‘Candidatus Phytoplasma trifolii’ in Rhododendron hybridum

“…'Candidatus Phytoplasma trifolii', a novel Candidatus species was designed for the clover proliferation phylogenetic group and is represented by the reference strain, clover proliferation phytoplasma (CP R ). Three subgroups have been classified by sequence homology and by the collective RFLP patterns of amplified 16SrRNA genes: CP-A, CP-B and CP-C (Hiruki and Wang 2004). Plants affected by 16SrVI phytoplasma group have been found in North America and Asia; few reports on wild plants have been published in Europe.…”

“…The phytoplasma was identified as a member of clover proliferation phytoplasma group (16SrVI group) (Lee et al 1998) or ('Candidatus Phytoplasma trifolii') (Hiruki and Wang 2004).…”