Analysis of the Developmental Regulation of the Cyanogenic Compounds in Seedlings of Two Lines of \u3cem\u3eLinum usitatissimum\u3c/em\u3e L.

The developmental profiles and tissue distribution of the four cyanogenic compounds in seedlings of two developmentally contrasting inbred lines of flax (Linum usitatissimum L.) were examined using HPLC. During germination, the isoleucine-derived compound, neolinustatin, was hydrolysed faster in the more vigorous of the two lines. Furthermore, in this line, the neolinustatin content was higher in seeds and the accumulation of the other isoleucine-derived compound, lotaustralin, was also higher in the cotyledons of seedlings. In contrast, with one exception, the hydrolysis and accumulation of the valine-derived compounds, linustatin and linamarin, was the same in both lines. Differences in the levels of the compounds during germination, and in the hypocotyls, are interpreted as evidence for the involvement of transient levels of hydrogen cyanide in the autocatalytic regulation of ethylene production

Preliminary Characterization of Peroxidase Isozymes Isolated from Two Flax Genotrophs

Four peroxidase (EC 1.11.1.7) isozymes were isolated from each of two flax genotrophs. All four isozymes were glycoproteins and all exhibited indoleacetic acid (IAA) oxidase activity. The percentage purity of two of the isozymes was very high; these isozymes differed in percentage carbohydrate and in peroxidase and IAA oxidase specific activities. Three of the isozymes displayed molecular weight values of about 43 000; for the fourth, molecular weight was considerably higher. Corresponding isozymes from the genotrophs and from two other flax genotypes displayed molecular weight differences which corresponded to electrophoretic relative mobility differences. Enzyme yield per unit fresh weight was higher for one genotroph than the other, and the balance between peroxidase activity and IAA oxidase activity between the genotrophs was different

Measurement of Activity of Peroxidase Isoenzymes in Flax (\u3cem\u3eLinum usitatissimum\u3c/em\u3e)

Peroxidase isoenzynles may be separated on acrylamide gels and then detected by supplying the substrate in an appropriate reaction system. One such system frequently used contains guaiacol as the hydrogen donor, although this compound has certain drawbacks. Ways of circumventing these drawbacks are suggested, so that quantitative estimates of the activity of individual peroxidase isoenzymes may be obtained

Isolation of Peroxidase Isozymes from Two Flax Genotypes by Column Chromatography

Isolation of the four major peroxidase isozymes (isozymes 1, 2, 3, and 4) of two flax genotypes was achieved by modifying the procedure used by Shannon et al. (1966) for the isolation of horseradish peroxidase isozymes. The net positive and net negative charges of isozymes 1, 2, and 4 were different. Isozyme 3 resembled isozyme 4 in charge but differed in apparent molecular weight. The chromatographic elution profiles of both genotypes were the same. Anionic gel electrophoresis demonstrated that after isolation and repurification, relative mobility differences existed between the corresponding isozymes of the two genotypes for all four isozymes