Circadian rhythms of ethylene in arabidopsis

Arabidopsis seedlings displayed a robust, circadian rhythm of basal ethylene levels in light and darkness. The light-entrained rhythms indicate that ethylene evolution is controlled by the circadian clock in Arabidopsis thaliana seedlings, with a peak in the mid-subjective day.

Wild-type Col-0 seedlings were grown for 6 days under photoperiod of 12 h light/12 h dark (LD 12/12) - black symbols or 12 h light/8 h dark (LD 16/ 8) - white symbols and tested for ethylene released during one photoperiod LD cycle followed by constant light. The phase of the ethylene production was shifted later by 2 to 4 h in LD 16/ 8 entrained plants compared with LD 12/ 12 entrained plants. Consequently, ethylene production peaked around subjective midday in both cases.