Die Trennung von Zellteilung und Suberinsynthese in dereprimiertem pflanzlichem Speichergewebe durch Tris-(hydroxymethyl-)aminomethan

Abstract

Differential derepression of the genome of potato tuber cells by slicing of the tuber tissue leads to cell divisions. This mitotic activity is totally suppressed by Tris-(hydroxymethyl)-aminomethane (Tris)-buffer widely used in biochemical research. The blockage is reversible if tissue slices are transferred to water in order to wash out the Tris-ions.The actual reason for the inhibition of mitotic activity by Tris is as yet unknown. As a possible mechanism of action an uncoupling of electron transfer from phosphorylation in the mitochondrial respiratory chain is discussed. However, experiments show no difference in O2-absorption between Tris-treated tissue and control in water. Moreover the application of several inhibitors of respiration causes exactly the same effects in both tissues. Amytal (blockage of flavoproteids) has no influence on the respiratory rate at any time. Antimycin A (blockage of electron flow from cytochrome b to cytochrome c) as well as HCN (inhibition of cytochrome-oxidase) inhibit respiration of both tissues during the first 24 hours after derepression. Later on the respiration becomes resistant to both inhibitors. So the quality of respiration is assumed to be the same in mitotic active potato slices as in the Tris-treated tissue.Recent results of biochemical analyses of events in carbohydrate breakdown of the tissues in question point to a differential effect of Tris on several enzymes as possible reason for its inhibitory action.

Inhibition of the Development of a Cation Accuniulatory System and of Tris‐induced Uptake in Storage Tissues by N6‐benzyladenine and Kinetin

“…An interesting aspect is that unlike beetroot disks swede disks do not show a distinct lag phase in the development of cation uptake capability and, instead of stimulating cation uptake tris has an inhibitory effect on swede disks. Tris might also cause a modification of developmental processes during the aging of disks, an idea which finds support in the observation of Kahl et al (1969) that mitotic activity in potato disks is totally suppressed by high concentrations of tris.…”

Der Glucosestoffwechsel dereprimierten pflanzlichen Speicherparenchyms nach Hemmung der Mitoseaktivitat durch Tris‐ (hydroxymethyl‐) aminomethane

“…Die -nach Auswaschung des Trisions reversible -Hemmwirkung kann somit nicht auf eine Beeinflussung der Atmungskette oder eine Entkopplung der oxydativen Phosphorylierung zuriickgefuhrt werden (vgl. Kahl et al 1969 a).…”