What is phototropism in plants? Phototropism of plants

The phototropism of plants is:The phenomenon of growth bending caused by unidirectional light irradiation of plant growth organs is called phototropism. For higher plants, phototropism mainly refers to the positive phototropism of the stems and leaves of the aboveground parts of plants.

In the past, roots were thought to have no phototropic reaction, but in recent years, Arabidopsis thaliana has been used as a research material, and roots have been found to be negatively phototropic.

Impact:

Under the action of unilateral light, auxin.

Lateral transport from the tip of the stem to the backlit side down the parenchyma tissue, the auxin concentration on the backlit side is higher than that on the phototropic side, and the cell growth on the backlit side is greater than that on the phototropic side, which causes phototropic bending. Winter demonstrated that the auxin content of the tip of the coleoplasty on the backlit side diffusing to the agar was almost twice that of the light-side when the oat germ sheath was irradiated on one side.

It is speculated that auxin movement is due to the potential difference between different parts of the coleopleoplasty tip caused by unidirectional light.

The side to the light is negatively charged, and the side of the backlight is positively charged, indoleacetic acid.

It is weakly acidic, and its anion.

Move to the backlit side, so that the backlit side has a high auxin content and grows faster, and the plant shows phototropic growth. But this approach has not yet been proven.

The above content refers to the Encyclopedia - Phototropism.

Phototropism is a major characteristic of plants, it should be said that almost all plants can be said to be phototropic plants, for example, sunflowers, peas, cotton, corn, trees, etc.

Almost all plants are phototropic, but there is a subtle difference here: phototropism is strictly like a sunflower "looking at the sun" all the time, but broadly speaking, all plants are phototropic: they grow in the direction of sunlight, not in the soil.

The small sunflower that lives in the Arctic is as big as a moss. Wherever the sun goes, it turns. The sun didn't appear, it hung low.

Plants need to photosynthesize to make nutrients, and the production of plants to sunlight is the result of natural selection evolution, and those plants that did not grow towards sunlight before are basically extinct, and the only ones left are to grow towards sunlight.

bamboo, cotton, fortune tree, peas, corn, wheat.

Potatoes, wheat, sunflowers, peas and much more.

Most plants are phototropic and a few plants are not.

Do you know the phototropism of plants? Do you know why plants grow in the direction of sunlight? I mentioned in the journal We Love Science that plants grow in the direction of light, and in order to confirm this claim, I decided to do my own experiments to verify it.

First of all, I prepared a mung bean seed, a vegetation filled with soil, a small cardboard box and three pieces of cardboard, then buried the mung bean seeds in the soil, and then used cardboard to separate a few squares in the paper cup to form a simple maze, open a window on one side of the cardboard box, put the paper cup in the corner of the carton away from the window, and finally sealed the carton and placed it on the balcony. Two weeks later, the mung bean sprouts poked their heads out of the small carton window! I hurriedly opened the cardboard box and was stunned by the sight of mung bean sprouts zigzags winding around the labyrinth of cardboard to reach the window.

Why is that? It turns out that plants are phototropic. The phototropism of plants is due to the inhomogeneity of auxin.

Auxin also refers to the growth hormone in the plant, which can promote the growth rate of the plant, but it does not like sunlight, so it is always hidden on the backlit side of the plant. If there is too much auxin on the backlit side, the growth rate of the plant will increase, and the plant will bend towards the light.

There are also some plants that "chase" the sunlight to grow, such as sunflowers, the leaves on its stems can get more sunlight and accelerate photosynthesis, and the flowers chasing the light side can make themselves more vivid and fragrant, attracting more insects to impart pollen.

The most light-sensitive parts of the plant are the young shoot tips, germ tips and seedlings. They can catch even the faint light that looks like it to our naked eyes. This is the secret of plants growing towards the sun!