The interaction of 2,4-dichlorophenoxyacetic acid, ribosomes and polyamines in Azospirillum brasilense.

2,4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide used extensively in agriculture. We had previously determined that 1 mM 2,4-D could inhibit cell growth, DNA and protein synthesis of Azospirillum brasilense. The present work was designed to determine if these alterations are a consequence of 2,4-D action on polyamine biosynthesis and if the protein synthesis inhibition is a result of ribosomal impairment. In this paper we demonstrate that 2,4-D alters the metabolism of polyamines and, thus, affects protein synthesis at the ribosomal level.