Decoding Cuscuta coiling with image processing

Materials and methods

• Mature Cuscuta stem segments grown in greenhouse.
• Inoculated on skewers at 9AM, 12PM, and 4PM.
• 900 camera snapshots × 96 seconds = 24 hours.
• 5 skewers × 7 repetitions = 35 samples per time.
• Manual and automated observations:
  ↪ Coiling success rates.
  ↪ Initiation and completion times.

More data extracted automatically

• Keep track of coil position and angle as a time series:
  ↪ Observe nuanced coiling stages.
  ↪ Consider Coil 1 and Coil 2 individually.
  ↪ More accurate representation.
• Based on color contrast Cuscuta vs skewer.
  

The early dodder gets the host

• Cuscuta inoculated in the morning coiled better:
  ↪ Higher coiling success rate.
  ↪ Coiling started sooner.
  ↪ Coiling was completed sooner.
• However, once coiling initiated, coiling stages lasted the same, regardless of inoculation time.
• Inoculation time did not influence twinning speed, angle, position, or coiling stage durations.
• Nonetheless, Coil 2 is more stable than Coil 1.

Circadian clock model and conclusions

• Cuscuta can tell time despite lacking photoreceptors.
• It prefers to act in the morning/early afternoon.
• Our pipeline is ready to collect more data:
  ↪ Phenotype the wiggle as a whole.
• Improve parasitic plant control treatments.