Effect of ethylene, cytokinin, and KNAT2-GR activation on trichome number. The number of trichomes was quantified on the first leaves of 3-week-old KNAT2-GR, ctr1-10, and ctr1-10/KNAT2-GR in the absence of DEX (white) or in the presence of 0.1 μm DEX (black). The number of trichomes was also quantified on the first leaves of 3-week-old KNAT2-GR plants grown in the presence of 10 μm ACC, or 0.1 μm 6-benzylaminopurine (BAP), or 10 μm ACC and 0.1 μm BAP, in the absence of DEX (white) or in the presence of 0.1 μm DEX (black).