Root
Caps and Their Effect on Gravity Sensing
It has been hypothesized that the root cap is one of the main
gravity sensing organs on a plant. This series of experiments
tests the angle of growth over time and the growth rate of roots,
both of normal roots and decapitated roots.
Click here to view magnified images of root caps, to see where the root should be decapped
Experimental Design of What was Done in the Lab:
(Click Here for Step by Step Photos)
o Imbibe maize seeds for 24 hours.
o Plant seeds between 2 plates of
glass and wet paper towels, cover with plastic wrap
to hold together and retain moisture.
o Place in trough of water and let
germinate for about 2 days, being sure to rewet the top of the
paper towels in the glass so the plants do not dry out.
o Look at seedlings, pick out plants
with a good root length (1-2cm) and decap.
o Decapping is done under a
dissection microscope with forceps and a razor blade.
o Mount seedling on plate, either
with a nutrient gel or damp filter paper to maintain
moisture, and seal with parafilm.
o Set up camera, Rotate plant plate 90 degrees, and Capture the movie!
o Analyze growth patterns using NIH Image
See what happened!
This movie shows 6 hours of growth of an intact and decapped root in 20 seconds, so the growth you see here is about 1000 times slower in real life.