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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Molecular Plant Pathology Laboratory » Research » Publications at this Location » Publication #326228
Title: ‘Candidatus Phytoplasma hispanicum’, a novel taxon associated with Mexican periwinkle virescence disease of Catharanthus roseus

Author
item Davis, Robert
item HARRISON, N - University Of Florida
item Zhao, Yan
item Wei, Wei
item DALLY, ELLEN - Retired ARS Employee

Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2016
Publication Date: 9/1/2016
Citation: Davis, R.E., Harrison, N.A., Zhao, Y., Wei, W., Dally, E.L. 2016. ‘Candidatus Phytoplasma hispanicum’, a novel taxon associated with Mexican periwinkle virescence disease of Catharanthus roseus. International Journal of Systematic and Evolutionary Microbiology. 66:3463-3467. doi: 10.1099/ijsem.0.001218.

Interpretive Summary: Minute bacteria known as phytoplasmas are responsible for serious diseases of crop plants and plants in natural habitats around the world. Many harmful phytoplasmas occur outside North America, and it is important to prevent these “exotic” phytoplasmas from entering the USA. One such phytoplasma is called Mexican periwinkle virescence (MPV) phytoplasma, of which related strains cause diseases in plants growing in Mexico and South America. There is need to identify this phytoplasma by a specific name, and to obtain precise molecular markers for identification and classification of the phytoplasma, to aid the design of safe and effective disease control measures and to enable quarantine measures that effectively prevent spread of the of the phytoplasma across national borders. Using molecular methods to study specific genes, we found that the MPV phytoplasma represents a previously undescribed species level lineage, for which we have proposed the designation, ‘Candidatus Phytoplasma hispanicum’. Our results provide genome-based molecular markers by which ‘Candidatus Phytoplasma hispanicum’ may be detected and identified, benefitting measures to control diseases caused by this phytoplasma, as well as aiding implementation of quarantine measures to prevent its spread. Such progress will aid the cause of food security and sustainable agricultural production. This report will be of interest to diagnostics laboratories, research scientists, farmers, and quarantine agencies internationally.

Technical Abstract: Mexican periwinkle virescence (MPV) phytoplasma was originally discovered in diseased plants of Madagascar periwinkle (Catharanthus roseus) in Yucatán, Mexico. On the basis of results from RFLP analysis of PCR-amplified 16S rRNA gene sequences, strain MPV was previously classified as the first known member of phytoplasma group 16SrXIII, and a new subgroup (16SrXIII-A) was established to accommodate MPV phytoplasma. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain MPV represents a lineage distinct from previously described ‘Candidatus Phytoplasma’ species. Nucleotide sequence alignments revealed that strain MPV shared less than 97.5% 16S rRNA gene sequence similarity with all previously described ‘Ca. Phytoplasma’ species. Based on unique properties of the DNA, we propose recognition of Mexican periwinkle virescence phytoplasma strain MPV as representative of a novel taxon, ‘Ca. Phytoplasma hispanicum’.