title: A single base pair in the right terminal domain of tomato planta macho viroid is a virulence determinant factor on tomato.
abstract: Tomato planta macho viroid (TPMVd), including isolates previously designated as Mexican papita viroid (MPVd), causes serious disease on tomatoes in North America. Two predominant variants, sharing 93.8% sequence identity, incited distinct severe (MPVd-S) or mild (MPVd-M) symptoms on tomato. To identify virulence determinant factor, a series of chimeric infectious clones were generated using synthetic DNA approach to progressively replace each structural domain between the two variants. In bioassays on tomato 'Rutgers', three chimeras containing Terminal Left and Pathogenicity (MPVd-H1), Central (MPVd-H2), or Variable (MPVd-H3) of MPVd-S, incited mild to intermediate symptoms. However, a chimera containing Terminal Right (TR) of MPVd-S (MPVd-H4) incited severe symptoms. Only one base-pair mutation in the TRdomain between MPVd-M (176U:A185) and MPVd-S (174G:C183) was identified. A reciprocal mutant (MPVd-H5) rendered the chimeric viroid mild on tomato. This single base-pair in the TRdomain was determined as the virulence determinant factor for TPMVd.
authors.affiliation: U.S. Department of Agriculture - Agricultural Research Service, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC, USA; Agdia Inc., 52642 County Road 1, Elkhart, IN 46514, USA. Electronic address: Rugangli@yahoo.com.
authors.forename: Rugang
authors.initials: R
authors.lastname: Li
authors.affiliation: U.S. Department of Agriculture - Agricultural Research Service, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC, USA. Electronic address: Chellappan.Padmanabhan@ars.usda.gov.
authors.forename: Chellappan
authors.initials: C
authors.lastname: Padmanabhan
authors.affiliation: U.S. Department of Agriculture - Agricultural Research Service, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC, USA. Electronic address: Kai.Ling@ars.usda.gov.
authors.forename: Kai-Shu
authors.initials: KS
authors.lastname: Ling
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D018551:Solanum lycopersicum / Q000821:virology*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000821:virology*; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014772:Viroids / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D014774:Virulence; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins; D037521:Virulence Factors
keywords: Infectious clone; Mexican papita viroid; Recombinant viroid; Solanum lycopersicum; Tomato disease; Tomato planta macho viroid