Have you ever wondered how a plant grows up or down? This behavior of plant beings is somewhat curious, because here on Earth we have a gravity high enough for everything around us, including ourselves, to stay on the earth’s crust, on the ground.
However, trees, flowers, herbs … almost all plants grow as if they wanted to touch the sky. Why?
Although the roots penetrate the soil looking for moisture and can also ensure a good anchorage, the stems do it in the opposite direction looking for light because thanks to solar energy they will be able to carry out photosynthesis and therefore grow. But how can the plant know where direct the development of each of its parts? Does the seed hold all that information?
Well, although it seems incredible, so is. In fact, you can do the following experiment at home to check it:
- Grab a container of milkand put it horizontally on a table.
- Cut off a sidemaking a downward cut.
- Now, fill it with substrate and place a seed (pea, for example) right in the middle of the container, away from the side where you cut, but without being at the other end.
- Finally, waters.
In a few days you will see that its first leaflets (the cotyledons) will begin to appear on the side that you have cut, upwards.
Although even today it is unknown why exactly this happens, this theory is considered valid: the force of gravity may attract both liquid cell content and its starch. This could be the equivalent of our inner ear, thanks to which we keep ourselves in balance by being able to distinguish what is above and what is below.