RAPID AUXIN-INDUCED ENHANCEMENT OF PROTEIN-BIOSYNTHESIS IN RYE COLEOPTILES

The effect of auxin (indole-3-acetic acid, IAA) on growth and incorporation of H-3-leucine into cytoplasmic and cell-wall bound proteins of abraded coleoptile sections from rye seedlings (Secale cereale L.) was investigated. In the absence of IAA (water control) a strong incorporation of tracer into both protein fractions was observed. Auxin rapidly increased the incorporation of H-3-leucine into both cytoplasmic and cell-wall fractions of the coleoptiles in close temporal correspondence to the growth response of the sections. The uptake of tracer was unaffected by the hormone. However, auxin did not alter the pattern of protein synthesis as measured by H-3-leucine labelling, i.e. we were unable to detect a specific polypeptide that is synthesized de novo in response to IAA.