On the synthesis of protoheme and peroxidase in suspension cultures of Nicotiana tabacum [tobacco]
1981
Maeder, M. | Fuessl, T. | Walker, E. (Heidelberg Univ. (Germany, F.R.). Inst. fuer Botanik)
The protoheme content of tobacco suspension cultures grown in continuous dark - yielding chlorophyll free cells - shows a peak on the 9th day of a two-week culture cycle. The peaks of enzymes of the porphyrin metabolism occur on the same day (porphobilinogenase) or one or two days earlier (delta-aminolaevulinic acid dehydratase). The ratio protoheme content/peroxidase activity - a value for non peroxidase-bound heme - increases markedly at the beginning of exponential growth then decreases to initial values after day 9. Representing the transition of exponential to stationary phase, day 9 is characterized by inhibition of protein, i.e., enzyme synthesis and by gradual decomposition of cellular structures. However, peroxidase synthesis continues beyond this transition. Various possibilities for protoheme supply are discussed.
Показать больше [+] Меньше [-]Библиографическая информация
Эту запись предоставил European Union
