title: Temporal expression of PR-1 and enhanced mature plant resistance to virus infection is controlled by a single dominant gene in a new Nicotiana hybrid.
abstract: A new variety of Nicotiana edwardsonii, designated N. edwardsonii cv. Columbia, expresses pathogenesis-related (PR) proteins in a temporal manner 45 to 49 days postplanting and also exhibits enhanced resistance to Tobacco mosaic virus, Tobacco necrosis virus, and Tomato bushy stunt virus. In contrast, PR proteins were not expressed in the original N. edwardsonii variety at comparable ages but were induced after onset of a hypersensitive response to viral infection. The temporal induction of PR proteins in 'Columbia' was correlated with increases in salicylic acid and glycosylated salicylic acid. Earlier studies noted that some Nicotiana hybrids derived from interspecific crosses constitutively express PR proteins, but the genetic basis of this phenomenon had not been investigated, likely because many interspecific Nicotiana crosses are sterile. However, the close genetic relationship between N. edwardsonii and 'Columbia' indicated that a hybrid between these two plants might be fertile, and this proved to be true. Genetic crosses between 'Columbia' and N. edwardsonii demonstrated that a single, dominant gene conditioned temporal expression of PR proteins and enhanced resistance. This gene was designated TPR1 (for temporal expression of PR proteins).
authors.affiliation: Department of Plant Microbiology and Pathology, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Cole
authors.forename: Lóránt
authors.initials: L
authors.lastname: Király
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Lane
authors.forename: B Elizabeth
authors.initials: BE
authors.lastname: Wiggins
authors.forename: Kathleen
authors.initials: K
authors.lastname: Ross
authors.forename: James E
authors.initials: JE
authors.lastname: Schoelz
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D007113:Immunity, Innate / Q000235:genetics; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D014026:Nicotiana / Q000235:genetics* / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000472:pathogenicity*; D017898:Tobamovirus / Q000472:pathogenicity*
chemical_list: D029681:Arabidopsis Proteins; C077262:PR-1 protein, Arabidopsis