title: Extremely low frequency weak magnetic fields enhance resistance of NN tobacco plants to tobacco mosaic virus and elicit stress-related biochemical activities.
abstract: Increasing evidence has accumulated concerning the biological effects of extremely low frequency magnetic fields (ELF-MFs) in different plant models. In the present study, effects of ELF-MFs in tobacco plants reacting to tobacco mosaic virus (TMV) with a hypersensitive response (HR) were evaluated. Plants were exposed for 8 or 24 h (either before or after TMV inoculation) to a static MF, at either -17 or 13 microT, combined with a 10 Hz sinusoidal MF with different intensities (25.6 or 28.9 microT). The working variables were the area and number of hypersensitive lesions in leaves. Following ELF-MFs exposure, an increased resistance was detected, particularly after an 8-h treatment, as shown by the decrease in lesion area and number. Moreover, two enzyme activities involved in resistance mechanisms were analyzed: ornithine decarboxylase (ODC) and phenylalanine ammonia-lyase (PAL). Uninoculated leaves previously exposed to ELF-MFs in general showed a significant increase relative to controls in ODC and PAL activities, in particular for 13 microT static MF plus 28.9 microT, 10 Hz sinusoidal MF (24 h) treatment. In conclusion, ELF-MFs seem to influence the HR of tobacco to TMV, as shown by the increased resistance and changes in ODC and PAL activities, indicating the reliability of the present plant model in the study of bioelectromagnetic interactions.
authors.affiliation: Dipartimento di Scienze e Tecnologie Agroambientali, Università di Bologna, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Trebbi
authors.forename: Francesco
authors.initials: F
authors.lastname: Borghini
authors.forename: Lisa
authors.initials: L
authors.lastname: Lazzarato
authors.forename: Patrizia
authors.initials: P
authors.lastname: Torrigiani
authors.forename: G Lorenzo
authors.initials: GL
authors.lastname: Calzoni
authors.forename: Lucietta
authors.initials: L
authors.lastname: Betti
mesh_terms: D004574:Electromagnetic Fields; D009955:Ornithine Decarboxylase / Q000378:metabolism / Q000528:radiation effects; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism / Q000528:radiation effects; D010935:Plant Diseases / Q000821:virology*; D014026:Nicotiana / Q000378:metabolism / Q000528:radiation effects*; D014027:Tobacco Mosaic Virus
chemical_list: D009955:Ornithine Decarboxylase; D010650:Phenylalanine Ammonia-Lyase