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A comparative study on a pure cationic and a pure anionic protein from peanut cells and petunia stem tissue respectively, both with peroxidative activity, was made. The cationic protein weighs 44 Kd and the anionic 36 Kd. No immunological cross reactivity could be detected between the two proteins. In assays for peroxidative activity using the substrates 4-aminoantipyrine, guaiacol and eugenol it was noted that the anionic protein had 1.9, 12.7, and 27.7 fold greater enzymatic activity, respectively. For overall peroxidative measurements it is suggested that aminoantipyrine is probably the superior substrate. With regard to IAA oxidase activity of the two protein fractions it was noted that the cationic enzyme possessed optimal activity at pH 3.6 and the anionic protein at pH 7.0. The latter value could only be obtained by the addition of H2O2 and dichlorophenol (DCP). Since no additives were needed for the assay of IAA oxidation by the cationic protein it is suggested that this is a true IAA oxidase while the anionic fraction is a peroxidase involved in other reactions such as lignin biosynthesis.

Transient expression of chloramphenicol acetyl transferase gene has been detected in cultured barley (Hordeum vulgare L. cv. Heartland) cells and freshly isolated immature zygotic embryos (cv. Ellice) following the introduction of the gene by microprojectile bombardment. The DNA expression vector used to introduce the CAT gene, pCaMVI1CN, is a pUC8 derivative and consisted of a CaMV35S promoter, a fragment of alcohol dehydrogenase intron1, a CAT coding region and NOS polyadenylation region. The inclusion of the Adh1 intron1 was essential for the expression of CAT activity in cultured cells as well as immature zygotic embryos. Expression of CAT activity, which was dependent upon the DNA concentration used, could be detected as early as 20 h after bombardment. The results also suggested that the recipient cells have to be in an active state of cell division in order for the introduced gene to be expressed since mature zygotic as well as somatic embryos failed to reveal any gene expression. The effect of other parameters which influence the expression of the introduced gene as well as the potential of this novel technology for cereal transformation are also discussed.

Two peroxidases, one anionic and one cationic, have been purified from the proteins secreted by peanut (Arachis hypogaea L. var Virginia 56R) cells in suspension culture. These two peroxidases apparently have identical catalytic properties.

By inserting nitrocellulose strips into agarose gels alongside the electrophoresed lanes and passing an electric current perpendicularly in the direction of the strips, highly efficient transfer of DNA bands onto the membrane in the form of concentrated dots is achieved. DNA detection limits by this technique are enhanced, at least three times as visualized by ethidium bromide fluorescence and at least twice more by radiolabeling.

Treatment with gibberellic acid (GA3) enhances the number of adventitious roots and the number and length of sprouted buds on stem cuttings of Ipomoea fistulosa. Such simultaneous promotion of both rooting and sprouting is in contrast to most earlier reports on the effect of GA3 on these processes.