After this water stress period,
each group of plants (control and PEG plants) was divided into two
groups: one group for the collection of root exudates and the other
to determine the relative growth rate after the removal of water
stress for 24h (recovery period). In the latter group, the nutrient
solution of the water-stressed plants (PEG plants) was replaced
with an identical one but without PEG, and the control plants
received a renewed SNS. During this experiment, the nutrient
solution was continuously aerated using an air pump and was
renewed on day 7 and the day before the assay. The volume was
adjusted daily to 720mL.