Methods continued...
Measurement of the plants
Two weeks after the seeds were sown, the seedlings were measured for
their shoot fresh and dry weights, and also the ethylene produced by each
of these conditions. The fresh shoot was massed and placed in test tubes.
Then it was cooked in an oven at 60 degrees Celsius for about three days and
then the dry weights of the plants were measured. The experiment was repeated
two times with about thirty replicas per condition per trial.
Ethylene measurement:
Ethylene evolution by the seedlings was measured by incubating six fresh plants
in a 5 mL syringe (1.5 mL volume) for 15 minutes. Then 1 mL was collected
and injected into a Photovac 10Splus GC (Photovac Inc., Markham, Ontario)
with a photoionization detector and a 40/60 Carbopack B column (Supelco Canada,
Oakville, Ontario). Ethylene levels produced by the seedlings were then calculated
based on a calibration curve.
The results that obtained were analyzed based on a variety of criteria. The
shoot fresh weight, dry weights and ethylene produced were measured. The dry
and fresh weights were used to determine the approximate amounts of solids
present in the plants in comparison to the water content. This gave an understanding
of the amount of glucose produced by the plants. The ethylene evolution of
the plants enabled one to determine the interactions between the different
hormones and ethylene because the phytohormone mutants were being used in
the study. Hormonal interactions are heavily interlinked. So the levels of
ethylene produced in this experiment could be used to predict if that particular
hormone is produced as a response to the ethylene release or if it is a trigger
for the release of ethylene. However, the hormone could also be just an independent
hormone that was released due to the presence of the salt stress. Using the
observations the nature of the interactions between the hormones was determined.