Abstract
The effectiveness of countercurrent distribution, Sephadex G-10 column chromatography and silicic acid partition column chromatography in the purification of gibberellin-like substances from extracts of etiolated Phaseoltu multiflorus seedlings, and elongating vegetative shoots of Arizona cypress (Cupressus arizonica Greene) and coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) was followed by the use of the barley half-seed α-amylase bioassay and dry-weight measurements. Countercurrent distribution resulted in a 10- to 30-fold reduction in the dry weight of the acidic, ethyl acetate-soluble fraction. Sephadex G-10 column chromatography further lowered the dry weight by about two-thirds. Silicic acid partition column chromatography separated gibberellin-like substances from each other and again reduced the dry weight. Enhancement of bioassay activity was noted at each step of the purification procedure. It is concluded that the above procedures constitute useful and efficient tools for the initial purification of gibberellin-like substances from plant tissue.