1. Partial purification of cytokinins in young Lupinus seeds was attempted by organic solvent extraction, silver precipitation, ion-exchange, paper-roll and paper chromatography, with assay systems using tobacco calluses and radish cotyledons. 2. A purified substance, component L (2.0mg) obtained from 17.3kg of seeds, is held on Dowex 50 at pH 3.0 and eluted with 3N NH4OH, is precipitated by silverions in acid solution, is detected on chromatogram by silver nitrate-bromophenol blue reagent, and has ultraviolet absorption spectrum with a peak at 261mμ and a minimum at 229mμ in ethanol. Component L stimulates cell-division of tobacco callus at the concentrations of 0.1 and 1mg/l, and is inhibitory to the degradation of chlorophyll of radish cotyledons. Therefore component L seems to be a purine derivative with cytokinin activity, and closely related, but not identical, to kinetin.
1. The fresh weight and length of plumular hook section of etiolated Alaska perseedling were remarkably increased by GA throughout 3 days incubation period. IAA had little effect on the fresh weight and length and made the basal portion of plumular hook section globular. KIN had little effect on fresh weight and made the section thick and short. 2. On the increase in the fresh weight, optimum concentration of GA was 10-4-10-3M and optimum concentration of sucrose was 2-4% in both cases of Control andGA treatment and in neutral and alkaline pH the increase was very little in both cases. 3. The GA treatment during the initial 2 hours of incubation period induced almost the same effect as that obtained by GA treatment throughout the incubation period (2 days) and the Control treatment during the initial 6 hours remarkably lowered theresponse of the section to GA. 4. By GA the length of cells in the basal portion of the section was remarkably increased and the width of cells in the widest portion of the section in cortex tissues was hardly affected.
A comsarison of mineral content was made between leaves of different ages and between plants cultured in various soil moisture conditions using rape (Brassica rapa) and cowpea (Vigna sinensis) as the plant materials. The younger leaves and the whole plant cultured in dry soil contain more potassium and a little more phosphorus but less calcium than the older leaves or the whole plant in wet soils, respectively. Magnesium and sodium contents showed, however, very little differences in these comparisons. It may be said that the development of drought tolerance in a plant through drought hardening seems to relate with some features similar to those in younger leaves of the plant with respect to mineral contents. The sum of cations, total millimoles and total milliequivalents, was usually maintained at almost constant levels in one experimental series.
The cell wall constituents of a marine seed plant, Zostera marina, were chemically investigated. They seemed roughly to consist of cellulose, hemicellulose and pectic substance just as in common land plants. However, the methoxyl content of the pectic substance was very low as compared with that of the latter, the extent being approximately only 12% of the total carboxyl group. It was found, in addition, that about 7% of ester-like sulfate was present in this substance. In view of these facts, the pectic substance seemed to participate in the ion absorption of this marine flowering plant.