Water-absorbent plastic side (wet side) of longitudinally halved roots from cucumber seedlings germinated under stationary conditions without hydrostimulation
Seven cucumber seeds were inserted into a crack within a block of water-absorbent plastic foam (upper depth 10 mm x lower depth 17.5 mm x H10 mm x W49 mm) so that the germinal pore side of the seed protruded from the plastic foam by 2 mm. For irrigation, a metal pipe with small holes was inserted into the plastic foam and connected to a port in an enclosing plastic container. The plastic foam was positioned at one side of the plastic container to allow emerged cucumber roots to grow into the air. A plastic syringe fitted with a tap and a tube for drawing water from the water reservoir was connected to the port of the plastic container. The syringe was used to supply 9 mL distilled water to the plastic foam to initiate imbibition of cucumber seeds. Extra Thick (2.45 mm) Blot Absorbent Filter Paper (70 x 41 mm) (Bio-Rad, Hercules, CA, USA) was held on the opposite side of the plastic container to the foam block using a bolt through a central hole. Seedlings were germinated for 18 h in the dark at 26 degree Celsius under stationary conditions, and then placed into RNAlater and stored at 4 degree Celsius overnight. A small section of root tip (0.5 mm) was removed, and a 1.5 mm section of the remaining root was divided longitudinally into the water-absorbent plastic (wet) side (this sample) and the opposite (dry) side (sample A2).