Phy.to.plas-ma.Gr.masc.n.phytosaplant;N.L.neut.n. Phytoplasma a form from a plant. Phytoplasmas are wall-less, nutritionally fastidi- ous, and phytopathogenic prokaryotes 0.2–0.8μm in diameter that morphologically resemble nonhelical members of the class Mollicutes. Sequencing of nearly full-length PCR-amplified 16S rRNA genes, combined with earlier studies, provided the first comprehensive phylogeny of the organisms and showed that they constitute a unique, monophyletic clade within the Mollicutes. These organisms are most closely related to members of the genus Acholeplasma within the Anaero- plasma clade as defined by Weisburg et al. Despite decades of efforts and recent progress, sustained pure culture in cell-free media has not yet been demon- strated for any phytoplasma. Their genome sizes have been estimated to range from 530 to 1,350kb, and the DNA G+C content is about 23–30mol%. The presence of a characteristic oligonucleotide sequence in the 16S rRNA gene, CAA GAY BAT KAT GTK TAG CYG GDC T, and standard codon usage indicate thaphytoplasmasrepresentadistinctgenus-leveltaxonfor which the name ‘Candidatus Phytoplasma’ has been adopted. At present, for any subtaxa within the pro- visional genus, the designation ‘Candidatus’ must still be used.
Gasparich G.E., A.B. (2020). ‘Candidatus Phytoplasma’. New York : John Wiley & Sons [10.1002/9781118960608.gbm01259.pub3].
‘Candidatus Phytoplasma’
A. Bertaccini;
2020
Abstract
Phy.to.plas-ma.Gr.masc.n.phytosaplant;N.L.neut.n. Phytoplasma a form from a plant. Phytoplasmas are wall-less, nutritionally fastidi- ous, and phytopathogenic prokaryotes 0.2–0.8μm in diameter that morphologically resemble nonhelical members of the class Mollicutes. Sequencing of nearly full-length PCR-amplified 16S rRNA genes, combined with earlier studies, provided the first comprehensive phylogeny of the organisms and showed that they constitute a unique, monophyletic clade within the Mollicutes. These organisms are most closely related to members of the genus Acholeplasma within the Anaero- plasma clade as defined by Weisburg et al. Despite decades of efforts and recent progress, sustained pure culture in cell-free media has not yet been demon- strated for any phytoplasma. Their genome sizes have been estimated to range from 530 to 1,350kb, and the DNA G+C content is about 23–30mol%. The presence of a characteristic oligonucleotide sequence in the 16S rRNA gene, CAA GAY BAT KAT GTK TAG CYG GDC T, and standard codon usage indicate thaphytoplasmasrepresentadistinctgenus-leveltaxonfor which the name ‘Candidatus Phytoplasma’ has been adopted. At present, for any subtaxa within the pro- visional genus, the designation ‘Candidatus’ must still be used.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
