Figure 9.

Effects of JA on root development of wild-type (Col-0), pft1-2, and coi1-1 seedlings. Wild-type and pft1-2 seeds were germinated and seedlings were grown for 4 d on 0.2× MS medium, and homozygous coi1-1 seedlings were selected from a coi1-1/COI1 segregating population in medium supplemented with 4 µm JA. A, Four-day-old seedlings were transferred and grown side by side over the surface of 0.2× MS agar plates supplied or not with 4 µm JA, and primary root growth was measured every 2 d. B, Relative primary root growth in response to 4 µm JA. C, Lateral root number. D, Relative lateral root formation. Error bars represent se from 15 seedlings. Different letters indicate statistical differences at P < 0.05. E, Photographs of representative wild-type, pft1-2, and coi1-1 seedlings illustrating the phenotype in response to JA. Relative primary root growth and lateral root formation were analyzed 8 d after transfer to JA. The experiment was repeated three times with similar results. Bar = 1 cm. [See online article for color version of this figure.]