Suc and nutrient supplements affect growth responses to ethylene. Temporal wave frequency, average root elongation rate over the 7-d period following germination and average root axis angle on d 7 are shown for Ler seedlings grown on 1.5% (w/v) Bacto-agar supplemented with Murashige and Skoog salts (A–C), with Okada and Shimura salts (D–F), or under zero nutrients (G–I), in aerated or sealed plates. For each category of plates, data are shown for 0% (w/v) Suc (solid bars) or with 3% (w/v) Suc added (open bars). The dashed lines in graphs C, F, and I indicate vertical root elongation (0°), and positive angles describe righthanded skewing when seedlings are viewed from the cotyledon downwards to the root tip. Bars are the mean of at least 25 pooled roots from at least six replicated plates. Error bars are the se.