[Metabolism of diphenylacetylglycine in higher plants]. / Beiträge zum Stoffwechsel von Diphenylacetylglycin in höheren Pflanzen.

Studies were conducted on the biotransformation of the growth-regulating diphenylacetylglycine. For this purpose this substance was radio-labelled prepared from (14COOH)diphenylacetic acid and glycine. In plants of wheat of the sort "Remo", barley of the sort "Certina", and tomatoes of the sort "Harzfeuer" the agent undergoes only a low metabolism. Diphenylacetic acid is not formed, therefore, the peptide linkages are rather stable. Only little quantities of more polar metabolites have been found, one of them being chromatographically indicated as diphenylacetylglycine glucose ester.

[The metabolism of fenazox in tomato plants]. / Untersuchungen zum Metabolismus von Fenazox in Tomatenpflanzen.

Results from investigations on the metabolism of 14C-Fenazox show that in 6-8 weeks old tomato-plants (sort "Harzfeuer") the agent undergoes a biotransformation. After chromatographic separation the structure of the biotransformation products was elucidated by comparison to authentic test substances, by derivatization as well as by means of physico-chemical methods. With that, the following metabolites were identified: non-transformed Fenazox, o-hydroxyazobenzene, o-hydroxyaniline, and p-hydroxyaniline. Probably, the agent is first transformed enzymatically or non-enzymatically into o-hydroxyazobenzene, then follows a reductive cleavage into o-hydroxyaniline and aniline. In its turn, the latter is transformed into o-hydroxy- and p-hydroxyaniline. Experiments in the field of transformation kinetics indicated that the concentration of the applied Fenazox rapidly decreases and that the first transformation product o-hydroxyazobenzene in the beginning increases and then again decreases in its concentration. With increasing application time it comes to an increase of the non-extractable residues.

Comparative Investigations on the Metabolism of 2-(2,4-Dichlorophenoxy)Isobutyric Acid in Plants and Cell Suspension Cultures of Lycopersicon esculentum.

The metabolism of [(14)CH(3)]2-(2,4-dichlorophenoxy)isobutyric acid (DIB) was studied in plants and cell suspension cultures of Lycopersicon esculentum Mill. sp. ;Lukullus'. Both plants and cells in suspension culture showed a rapid uptake of DIB from nutrient media. The metabolites, isolated by extraction with methanol and separated by chromatographic methods, were identified by enzymic, chemical, and spectrometric methods. Two conjugates of the carboxyl with 2 and 3 moles glucose per mole DIB and, to a smaller extent, its beta-d-glucopyranosyl ester, were formed in both intact plants and cell suspension cultures, but there were quantitative differences.

Abscisic Acid Metabolism in Intact Wheat Seedlings under Normal and Stress Conditions.

Metabolism of abscisic acid (ABA) was studied in intact seedlings of Triticum aestivum during 14 days. (2-(14)C)-ABA solution (2.5 × 10(-4) M) was applied to the roots of plants for 24 h; after that plants were further grown in nutrient solution. Distribution of radioactivity between ABA and its metabolites was investigated in shoots, roots, and remaining seed parts. In whole seedling as well as in different plant parts the level of free ABA is decreased rapidly during 3 days after application, whereas the level of conjugates rises. Acidic ABA metabolites were detected in low concentration. The growth behaviour of seedlings is correlated strongly with ABA metabolism. ABA application for 24 h inhibits plant growth for three days. If most of the ABA applied is transformed to conjugates the seedlings start to grow rapidly. No evidence was obtained that ABA conjugates are translocation forms or storage forms of ABA. Short time drought stress condition did not alter ABA metabolism in wheat.

[Uptake and distribution of Camposan in rye]. / Uber Aufnahme und Verteilung von Camposan in Roggen.

Experiments for uptaking and distribution of the culm stabiliser "camposan" with the agens ethephon are very important to tell something about the dwarf behaviour of the treated plants of rye. The radioactive labelled ethephon is infiltrated through the roots, leaves and cuttings of culms. Uptaking through the roots is more complete than those about the foliar dissepiment. Otherwise uptaking through the foliar dissepiment is higher than about the leaves only. After radioautographic experiments, culmcutting-experiments and experiments with intact rye in the 5--6 leaf-stage we have found that the agens is transported acropetal in the xylem of the plants after uptaking by the roots up to 3 days. The labelled ethephon is translocated in a higher concentration in the phloem after foliar dissepiment application. The concentration of the agens decreases in the investigated plants up to the 5th day enormously (40--50% and after then slightly following the degradation to gaseous compounds. During 4 days ethephon is metabolized to about 5--15% ethylene and additional to about 18--20% carbondioxide.