Gas exchange
Photosynthesis and respiration were measured under growth conditions in
plant growth cabinets, using a CIRAS 1 infra-red gas analyser fitted
with a standard broad leaf chamber (PP systems, Amesbury, USA), as
previously described (Dyson et al ., 2016). Measurements of gas
exchange under ambient growth conditions were taken on the
1st and 7th day for the cold (5 °C)
and warm (30 °C) treatment, and under control conditions. The maximum
capacity for photosynthesis (Pmax ) was estimated
at 20 °C and under 2000 ppm CO2 and 2000 µmol
m-2 s-1 light, as described
previously (Herrmann et al ., 2019b). All measurements were taken
between the 5-7th hour of the photoperiod and on a
minimum of 4 biological replicates.