Einfluß verschiedener Wuchsstoffe und Stoffwechselgifte auf Atmung und Zuckergehalt in dem Wurzel-regenerierenden Gewebe von Phaseolus vulgaris L.

Abstract

Summary In hypocotyl cuttings of Phaseolus vulgaris L., which had been subjected to the influence of various growth substances and metabolic inhibitors, changes in the oxygen uptake and in the contents of glucose, fructose and sucrose in the root regenerating tissue were investigated after 2, 4 and 6 days of regeneration. The cuttings were treated with the growth substances indole-3-acetic acid (IAA) and indol-3-butyric acid (IBA), with 2,3,5-triiodobenzoic acid (TIBA), an inhibitor of the basipetal auxin transport, and with the oxidative phosphorylation inhibitors 2,4-dinitrophenol (DNP) and sodium azide (NaN 3 ). The root regenerating tissue of the control cuttings evidenced a slight increase in the oxygen uptake per mg N with progressing regeneration. The total sugar content was in all regenerative stages below that of the initial stage. IAA and IBA resulted in a distinct promotion of root formation, which was more pronounced on treatment with IBA than with IAA. The oxygen uptake per mg N of the root regenerating tissue was clearly stimulated following treatment with IAA, but the effect was twice as great at all stages after treatment with IBA. In both cases the contents of glucose, fructose and sucrose were greatly increased, especially after 2 days of regeneration, but decreased slightly in the following period. TIBA resulted in an inhibition of root formation accompanied by a simultanous pronounced formation of callus within the hypocotyl. The oxygen uptake increased continuously throughout the entire period of treatment. Following an initial decrease in the sugar contents, the content of sucrose in particular increased greatly in the hypocotyl. After resulting in an initial inhibitory effect, DNP induced a promotion of the new-formation of roots, which was clearly demonstrable after 10 days of regeneration. Under the influence of DNP the oxygen uptake was considerably increased and the total sugar content was clearly above that of the control, especially after 2 and 4 days of regeneration. NaN 3 completely prevented the process of root formation. The oxygen uptake — apart from an initial increase — was strongly inhibited; the contents of sugars decreased likewise.