Leaf water status

Immediately following the gas exchange measurements, each leaf was detached and weighed to determine leaf fresh mass (F_M). The leaves were then placed in a plastic bag and with the cut-end submerged in distilled water and allowed to rehydrate in darkness at 5°C for 18 hours. After rehydration the leaves were dried using paper towels to remove any water on their surfaces, and then the leaves were weighed to determine the saturated mass (S_M). Leaves were then dried at 80°C for 48 hours to measure dry mass (D_M). The relative water content (RWC) of each leaf was then calculated as follows [46]: