The effect of indole-3-acetic acid on coleoptile extension growth in the absence of protein synthesis.

In wheat coleoptile sections cycloheximide inhibited over 90% of (14)C-leucine incorporation into protein within 10 minutes of its application. Even after 2-hour pretreatments with cycloheximide, IAA stimulated extension, suggesting that its growth-promoting action did not directly involve protein synthesis.Kinetic experiments with cycloheximide indicate that incorporation of a structural factor (possibly protein from a previously synthesised pool) into cell walls might be the rate-limiting process affected by IAA.