Effect of darkness on isoperoxidases in tobacco tissue cultures

Abstract

In order to study the effect of light on the tobacco tissue culture WR-132, 5 passages (10 days' growth per passage) of these cells were grown in darkness, and 3 passages were separately grown in intense light (16000 lx). All other growth conditions were the same. The resulting isoperoxidase patterns present in these cells and in their growth media were analyzed at 2-day intervals during this period and then compared with the isoperoxidase patterns of cells grown under dim light conditions (10 lx). A new cathodic isoperoxidase (Cn) appeared in the medium within 2 days after the cells were placed in the dark. Cn was present in all media of WR-132 cell cultures analyzed throughout the 5 passages grown in darkness. The fifth passage in darkness produced total cessation of growth (apparent death). Cn increased and new anodic isoperoxidases Aa, Ab, Ad and Ae appeared in the media as the cells approached death in darkness.