Understanding the Root Waving Phenomenon in Arabidopsis thaliana

Plant development is highly dependent on environmental cues and can be affected by gradients in water and nutrient resources, salinity, light, gravity and physical obstacles. A striking phenomenon observed in the development of Arabidobsis Thaliana roots is that when it is grown on an inclined agar plate, the roots form sinusoidal waving patterns or circular coils, depending on the tilt angle. In previous studies it has been suggested that the waving phenomenon is a result of the combined effect of the tendency of the root cap to grow in the direction of gravity and some unknown physiological mechanism which allows the root to avoid obstacles. In this research we are studying the hypothesis that the waving phenomenon is a result of the combination of gravitropism and a purely mechanical response from the root which does not necessarily involve active response on the side of the plant. To check this hypotheses we study the growth patterns in an agar plate situated with variable tilt angles and compare it to a mechanical theory that we developed.