2.2.The Sl-ERF.B.3 Gene Expression Study
Growth Conditions. Wild type tomato plants were grown in
compost (jiffy pots) under growth chamber conditions (16 h
light/8 h darkness, 25∘C and 80% humidity); all seedlings
were allowed to grow for 21 d before stress treatment.
Abiotic Stress Treatments. All stress treatments (salinity,
drought, flooding, heat, and cold) were applied at the
same vegetative growth stage (three-week-old plants). All
experiments were repeated three times and each replicate
corresponds to six plants. For the drought assay, watering
was withheld for 5d from plants grown in jiffy pots whose
weights were beforehand equilibrated by adding appropriate
volume of water to maintain the same soil water levels before
drought application. The salt stress was achieved bywatering
with 250mM NaCl solution and shoots harvesting 24 h later.
For the cold stress assay, plants were incubated at 4∘C for
8 h. To apply heat stress, plants were exposed to 42∘C for
8 h. The flooding stress was applied by immersing plants (at
cotyledon level) in deionised water for 72 h. Immediately
following application of each type of stress, the aerial parts
were removed and frozen in liquid nitrogen for later use for
RNA extraction