The Effect of Light on Tobacco Mosaic Virus (TMV) Formation

Abstract

Discs were punched from TMV-inoculated tobacco leaves {Nicotiana tahaciim L.) and illuminated while floating on half strength Vickery's solution maintained at 24 C. After 48 hours some discs were placed in the dark for 24 hours and the amount of TMV formed in the light and dark compared. Discs from young leaves formed more virus in the light than in the dark. Discs from older leaves produced less virus, but as much in the dark as in the light.

Effect of Light on Tobacco Mosaic Virus Formation under Anaerobic Conditions

“…TMV formation in infected discs requires suitable substrates and a supply of ATP. Substrates in the discs are probably not limiting as TMV is formed aerobically in both light and dark, and is only stimulated by light in discs from younger leaves (Olsson 1972). In darkness ATP is produced by respiration, and in the light by photosynthesis and only to a small extent by respiration unless photosynthesis is inhibited.…”

“…Inoculation and treatment of leaf discs Discs were obtained from infected and uninfected leaves of Nicotiana tahacum cv. White Burley as de-scribed in the previous paper (Olsson 1972) and floated on modified Vickery's solution in crystallising dishes. The dishes, covered with glass, were kept at 24 C in a waterbath and continuously illuminated (4000 lx) for 48 hours.…”

“…Discs were infiltrated with solutions in Thunberg tubes by evacuating the tubes and releasing the vacuum quickly. Discs were sampled before and after the experiments and stored at -20 C before TMV was extracted and measured as described in the earlier paper (Olsson 1972).…”