Delayed chlorophyll fluorescence
Seeds were sown in clusters of approximately 20 seeds, one cluster per
well in a 10 cm square 25 well plate. The dividing walls of the plate
were covered in black electrical tape, to reduce cross contamination of
signal between wells. After 10 - 12 days of entrainment, plates were
transferred into a NightSHADE LB 985 photon counting camera (Berthold
Technologies), controlled by IndiGOTM software. Plants
were grown in the camera box for one light/dark cycle before switching
to constant light conditions for imaging. Illumination in the camera was
maintained by light emitting diodes (LEDs) set to 24 % of maximum
emission for red (660 nm) and blue (470 nm) wavelengths to provide light
intensity 50 - 70 µmol m-2 s-2 at
plant height. Delayed fluorescence (DF) was measured at a wavelength of
560 nm for 60 seconds post illumination every hour for five days. Images
produced were analysed by IndiGOTM software,
background corrected and detrended. Background corrected data was
analysed using BRASS.