Fig. 3.

ett and arf4 affect leaf shape and trichome distribution. (A) Successive rosette and inflorescence leaves from wild-type and mutant plants, arranged from the base (left) to the tip (right) of the stem. ett and arf4 suppress the narrow, elongated phenotype of the first two zip leaves. Later leaves of double mutants have rounder tips than zip-2, and the distal portion of the leaf blade is often wider than the proximal portion. ett and arf4 do not affect the serration of the leaf blade. (B) The L:W ratio of the leaf blade of successive leaves of wild-type, ett-7 and arf4-2 plants (n=10 plants of each genotype; ±s.e.m.). In wild-type plants, this ratio increases gradually until leaf 8, after which it remains constant until flowering. ett-7 and arf4-2 cause leaves 4-7 to be slightly rounder than normal. (C) ett-15, ett-7 and arf4-2 increase the number of leaves without abaxial trichomes (black) in both a wild-type and a zip background. This is associated with a compensatory decrease in the number of adult leaves (grey; n≥18, ±s.e.m.). The number of cauline leaves is indicated by the white bar. The numbers above each bar represent the percentage of flowers with a split septum, based on an analysis of the first 10 flowers of five plants of each genotype. ett-15 and arf4 partially suppress the septum splitting observed in zip. Other arf4 mutations also delay abaxial trichome production in a zip-2 background. (D) The number of leaves without abaxial trichomes among plants segregating ett-7 and zip-2. ett-7 has a semidominant effect on abaxial trichome production.