Figure 4.
etr1-7 leaves are hyperresponsive to ethylene and propylene. A, Leaves of 4-week-old Col-0 wt and etr1-7 plants were collected after a 24-h treatment with air (A), 500 nL L−1 ethylene (E), or 500 μL L−1 propylene (P). Ten micrograms of total RNA was electrophoretically separated and northern blotted. The ethylene-responsive genes basic chitinase (ChiB) and PDF1.2 were used as molecular markers for ethylene sensitivity. Arabidopsis tubulin TUA3 was used as a loading control. B, Leaves of 4-week-old Col-0 wt and etr1-7 plants were collected after a 24-h treatment with either air (A) or 100 μL L−1 ethylene (E), which represents a saturating concentration. Five micrograms of total RNA was electrophoretically separated and northern blotted. ChiB and PDF1.2 were used as molecular markers for ethylene responsiveness. Tomato 18S rDNA was used as a loading control.