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Biomedical subjects

M A Venis

Publications and source records attributed to M A Venis.

28 records · Page 2Linked to original sources
PubMed1972

Auxin-induced Conjugation Systems in Peas.

Pretreatment of pea (Pisum sativum var. Alaska) sections with any active auxin induces an enzyme which forms aspartate conjugates of exogenously supplied indoleacetic acid, naphthaleneacetic acid, or benzoic acid. Whereas induction of this system is an absolutely auxin-specific process, another enzyme, which forms benzoylmalic acid, is induced both by auxins and by physiologically inactive aromatic carboxylic acids. Induction of both enzymes is abolished by low levels of RNA and protein synthesis inhibitors. The induction specificities and other characteristics of the two systems are compared.

Journal Article↗
PubMed1971

Stimulation of RNA transcription from pea and corn DNA by protein retained on sepharose coupled to 2,4-dichlorophenoxyacetic acid.

When crude extracts from pea or corn shoots are passed through a column of agarose coupled to a derivative of the synthetic plant hormone 2,4-dichlorophenoxyacetic acid, certain protein fractions are retained, whereas unmodified agarose adsorbs no protein. Appropriate elution yields a protein factor that stimulates DNA-dependent RNA synthesis (supported by Escherichia coli polymerase) by 40-200%. Preliminary evidence suggests that the factor may be influencing initiation of RNA chains.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1968

Does ethylene mediate root growth inhibition by indole-3-acetic Acid?

The effects of ethylene and of indole-3-acetic acid (IAA) on growth of excised pea root sections have been compared under a variety of conditions. After 16 hours treatment the inhibitory action of IAA is fully reversible on transfer of the root sections to IAA-free solutions. In contrast, inhibition by ethylene is almost totally irreversible. IAA inhibits growth from zero time; ethylene is generally without effect during the first 3 to 6 hours. The inhibitory action of ethylene is dependent on factors such as tissue age and solution composition which have no major effect on IAA inhibition. Ethylene production is enhanced by 100 mum IAA, but conditions which reduce the rate of ethylene evolution 2 to 3-fold at the same IAA concentration fail to affect the inhibitory action of IAA on elongation. It seems unlikely that ethylene can play more than a minor role in mediating inhibition of pea root growth by IAA.

Journal Article↗