Some Effects of Temperature on the Early Stages of Tobacco Necrosis Virus Multiplication

Abstract

SUMMARYThe number of infective centres which were established successfully following the manual inoculation of French bean leaves with tobacco necrosis virus strain D (TNVD) or with TNVD RNA, decreased with increasing temperature between 13 and 30 °C. At 3o °C or above, primary and probably also secondary infections could not be established, though it is likely that a limited amount of virus RNA and nucleoprotein was produced at 3o °C in cells in which infection had been established previously at 23 °C. During the first day after inoculation, 23 °C was optimal for virus accumulation. Between 23 and 3o °C the rate at which lesions increased in diameter decreased with increasing temperature. The inhibitory effect of supraoptimal temperatures on the establishment of infection may be due to degradation of the infective entity by ribonuclease(s).

Effects of Low Temperature on Stress Ethylene Biosynthesis in Soybean Hypersensitively Responding to Tobacco Necrosis Virus

“…This possibility, however, appears less convincing because GODEFROY-COLBURN et al (1986) found in tobacco hypersensitively responding to alfalfa mosaic virus that such a protein (P3) accumulated strongly at 10 °C. MCCARTHY et al (1976) found that low temperature (14 °C) did not substantially affect the rate of TNV-RNA accumulation in bean leaves. Our present results confirm that chilling does not affect accumulation of TNV antigen in soybean leaves.…”

“…MARTIN and GALLET (1966) found that at 13 °C, tobacco mosaic virus lesion size was decreased in tobacco hypersensitive to the virus. MCCARTHY et al (1976) found that accumulation of infective tobacco necrosis virus (TNV) RNA in bean was only slightly inhibited by low temperature, but no data on lesion size were given. As far as we know, there is no report giving information on the effect of chilling on stress ethylene produced during hypersensitivity.…”