Transgenically Produced Glycinebetaine Protects Ribulose 1, 5-bisphosphate Carboxylase/Oxygenase from Inactivation in Synechococcus sp.PCC7942 under Salt Stress

概要

論文の詳細を見る
Synechococcus sp.PCC7942 cells transformed with Escherichia coli bet genes accumulated glycinebetaine (to about 80 mM) and acquired an increased tolerance to salt stress. Ribulose 1, 5-bisphosphate carboxylase activity in the extract from control cells was found to decrease more rapidly than that of either PSI or PSII under salt stress. We examined levels of the transcript, the protein and the enzyme activity of ribulose 1, 5-bisphosphate carboxylase to determine at which level the enzyme is affected at the early stages of salt stress. The levels of rbcL mRNA in both control and bet-containing cells increased around two-fold under salt stress compared to those under non-stress. Bet-containing cells showed slightly reduced levels of rbcL mRNA under both non-stress and salt stress compared to control cells. The protein levels of the enzyme in the control and bet-containing cells were almost the same and were little changed by salt stress. On the other hand, salt stress drastically decreased the enzyme activity in control cells, but not as much in the bet-containig cells. Interestingly the lowered enzyme activity in extracts from control cells grown under salt stress, as well as acid-denatured enzyme, was partially reactivated by glycinebetaine.
日本植物生理学会の論文