Permeability changes in the hypersensitive reaction of Nicotiana tabacum cv. Xanthi nc. after infection with tobacco mosaic virus

Abstract

Changes in permeability in leaves of Nicotiana tabacum cv. Xanthi nc. after infection with tobacco mosaic virus (TMV) have been determined by measuring electrolyte leakage by conductometry. Measurements were carried out every hour from 16 h after inoculation until a a few hours after the appearance of symptoms, and from 2 h after transfer of infected plants from 32 to 22 °C until a few hours after symptoms appeared. Increased electrolyte leakage in the “normal” hypersensitive reaction was statistically significant from 7 h before the first symptoms became visible, and 1 h before cell collapse started after transfer from 32 to 22 °C. TMV-infected N. tabacum cv. Samsun did not show increased electrolyte leakage in the same period. The results indicate that permeability changes are an early event in the hypersensitive reaction of N. tabacum cv. Xanthi nc. following infection with TMV.