Circadian control of carbohydrate availability for growth in Arabidopsis plants at night

Plant growth is driven by photosynthetic carbon fixation during the day. Some photosynthate is accumulated, often as starch, to support nocturnal metabolism and growth at night. The rate of starch degradation in Arabidopsis leaves at night is essentially linear, and is such that almost all of the starch is used by dawn. We have investigated the timer that matches starch utilization to the duration of the night. The rate of degradation adjusted immediately and appropriately to an unexpected early onset of night. Starch was still degraded in an appropriate manner when the preceding light period was interrupted by a period of darkness. However, when Arabidopsis was grown in abnormal day lengths (28 h or 17 h)…

• JI
  John Innes Foundation
• M
  Max-Planck-Gesellschaft
• DF
  Directorate for Biological Sciences
• BA
  Biotechnology and Biological Sciences Research Council