Effects of 2,4-dichlorophenoxyacetic acid on polyamine transport and metabolism in Azospirillum brasilense Cd.

We had previously demonstrated that 1 mM 2,4-D inhibited cell growth, nucleic acid synthesis and protein synthesis (at the ribosomal level) of Azospirillum brasilense. These alterations were prevented by the presence of polyamines in the culture medium. On the other hand, polyamines did not affect the 2,4-D uptake. In this paper we demonstrate that 2,4-D alters the metabolism of polyamines and increases their uptake.