VIEW ARTICLE

Effect of Temperature on the Synthesis of Tobacco Mosaic Virus and X-protein in Nicotiana tabacum ‘Xanthi nc’. S. Kajita, Plant Pathology Laboratory, Faculty of Agriculture, Nagoya University, Nagoya, Japan; C. Matsui, Plant Pathology Laboratory, Faculty of Agriculture, Nagoya University, Nagoya, Japan. Phytopathology 62:615-620. Accepted for publication 10 January 1972. DOI: 10.1094/Phyto-62-615.

At 25 C, Nicotiana tabacum ‘Xanthi nc’ showed the hypersensitive response to tobacco mosaic virus (TMV) infection and formed necrotic local lesions on inoculated leaves. At 38 C, on the other hand, the plant showed the systemic response to TMV concentration. Although there was no difference in TMV concentration in plants given the two treatments, infective RNA and X-protein concentrations were higher in the infected plants at 38 C. Under both treatments, incorporation of ¹⁴C-leucine into TMV fraction increased throughout the incubation period. Net incorporation of ¹⁴C-leucine into the X-protein fraction occurred throughout the incubation period at 38 C, but not at 25 C. When the inoculated leaves were incubated 1 day at 38 C and then 1 day at 25 C, incorporation of ¹⁴C-leucine into the X-protein fraction occurred until the appearance of necrotic local lesions; thereafter no net incorporation occurred. The relationships between virus RNA and virus protein in the hypersensitive and systemic responses to virus infection are discussed.