Where does the plant know the direction of 'top' and 'bottom' to determine the direction of development?

French scientists have discovered that there are molecular-level motors in particles in plant cells, allowing plants to feel tilt and gravity to determine the direction of development.

According to the article published in the PNAS journal, French scientists have explained the abnormal behavior of particles in plant cells, allowing them to feel tilt and gravity. Experiments have shown that there are molecules at the molecular level that help these particles move.

Particles gravel balance statolith in wheat plants - (Photo: PNAS magazine).

In many animals (including humans), the sense of balance is ensured by the inner ear, where ear stones (eardrums) are present . When we tilt, move the ear stones under the influence of gravity stimulates sensitive hairs and we feel that our body's position has changed. This is necessary for people to move normally. Although plants do not move, they still need to feel gravity to determine what is "top" and "bottom" and choose the direction of growth. And to do this, plants have what is known as a balance stone (statolith in plant cells) , which are solid particles of matter in special cells. Stabilized statolith stones are deposited under the influence of gravity and thanks to them, plant organs can determine the direction they need to grow.

However, for a long time, science could not understand what allowed plants to feel exactly the changes in gravity and tilt. A pinch of particles or particles is an inaccurate tool for measuring inclination, because interactions between particles and friction will make the system ineffective. French biologists have discovered this secret. They first monitored the motion of each gravel particle with statolite balance in response to the inclination and found that the particles were quite different from the particle system. They flow from one place to another regardless of the angle of tilt like liquid.

But what makes balancing gravel particles act like a liquid and not stick together? To answer this question, the scientists simulated the entire system with the actual size in artificial cells that introduced micro particles. Comparing the behavior of their model with those of statolith gravel in living cells, French biologists concluded that the mobility of the mass of particles arises from the movements of individual particles. The reason that the non-stick particles and not attached to each other statolith particle is that there are molecular motors that work continuously to make them move.

Scientists plan to continue researching and understanding how plants feel the movement of gravel particles equaling statolith.