Efeitos de tiocarbamato e carbofurano na degradação do acido indol-3-acetico

AUTOR(ES)
DATA DE PUBLICAÇÃO

1979

RESUMO

The herbicide thiocarbamate stimulates the metabolism of indole-3-acetic acid by peroxidase as measured by enhancement of both indole-3-carboxaldehyde formation and chemiluminescence. Native peroxidase and peroxidase compound-II were altered during the interaction with thiocarbamate. A time dependent study showed that peroxidase incubated with thiocarbamate decreases the indole-3-carboxaldehyde formation and the chemiluminescence but not the oxygen consumption. This presumably indicates that the thiocarbamate interacts with an oxidized intermediate and not by altering the peroxidase activity. Indole-3-carboxialdehyde was able to covalently add to t-RNA and it was tentatively postulated that the auxin activity was preceeded by a modification of t-RNA induced by the excited indole-3-carboxaldehyde. An inhibition of this binding in the presence of thiocarbamate was observed. Probably this is the mode of action of this type of herbicides at cellular level in plants. Oxygen uptake, product formation and excited state generation in the presence of the insecticide carbofuran were inhibited. These insecticides acted as competitive inhibitors and concomitantly were degradated. The photon emission, together with both absorption and oxygen measurement, show this to be a rapid and reproducible method to study herbicide and insecticide interaction with enzymatic systems in vitro.

ASSUNTO(S)

inseticidas produtos quimicos agricolas herbicidas

ACESSO AO ARTIGO

Documentos Relacionados