Explain with botanical principles why plant leaves roll into a cylindrical shape at noon in summer20

In the middle of summer, the leaves of plants (especially grasses) will curl, and there are internal and external causes.

role. The external cause is that the temperature is too high, and the transpiration is greater than the absorption, causing the cells to lose water and curl. The internal cause is mainly due to the existence of vesicular cells in the epidermis on the leaves of grasses, and when the leaves lose too much water through transpiration, the vesicular cells wilt, so the leaves roll inward.

This is a phenomenon of adaptation of plants to the environment.

1.Reduces water evaporation.

2.Probably eaten by bugs.

The reason why the leaves of the plant roll into a cylindrical shape at noon in summer can be explained from a botanical point of view:

1.On the leaves of grasses, there are vesicular cells, which are distributed between two vascular bundles, forming a fan-shaped arrangement. These cells have a thin cell wall and contain large vacuoles that are associated with the curling and curling of the leaves and are also known as motile cells.

2.In the middle of summer, the transpiration of plants is intensified due to strong sunlight and high temperatures. At this time, the vesicular cells shrink due to water loss, and the leaves of the grass plant will curl to reduce the evaporation of water from the leaf surface, thereby reducing the plant's body temperature and protecting the plant from harm.

3.In the evening, the light decreases, the temperature decreases, transpiration weakens, the plant's ability to absorb water increases, the vesicular cells reabsorb water, and the leaves will.

Therefore, the fact that the leaves of the plant will roll into a cylindrical shape at noon in summer is a way for plants to adapt to the environment and a mechanism for plant self-protection.

In order to maintain its own water balance, plants will respond to stress by curling the leaves, reducing the light area, and reducing the supply cycle of water from their own branches to the leaves, so as to achieve this purpose! At the same time, there is also a factor to avoid long-term sunlight exposure caused by leaf tissue necrosis, to the temperature, sunlight weakened to a certain extent, and the reason for recovery, many plants have this characteristic!

Because it's too hot. The water evaporated.

In the course of evolution, plants have formed a self-resistance mechanism in response to water transpiration, reducing the area of sunlight exposure and reducing the rate of water transpiration.

The sun is too hot, which reduces water loss.

It is the rate of water loss on both sides of the leaf, which exceeds the speed of its own water distribution, resulting in the speed difference between the two sides of shrinkage, which makes the surface shrink in different areas, so it will shrink into a cylindrical shape.

The plant itself carries out drought resistance. Reduces transpiration of leaves.

Because they are slowly rooted and grow slowly, they can grow into towering trees when the soil is cultivated.

Anything may definitely have a small tree that grows into a towering tree, even if we people also grow from small to big.

Water is most abundant in growing plants. The water content of protoplasm is 80 90, of which chloroplast and mitochondria contain about 50. The vacuole contains more than 90. The water content of tissues or organs decreases with the increase of lignification, such as the water content of the fleshy part of melon and fruit can exceed 90, the young leaves are 80 90, the roots are 70 95, the trunk is 50 on average, and the dormant buds are about 40.

The least watery seeds are mature seeds, generally only 10 14, or less. Organs or tissues with vigorous metabolism have a high water content. Protoplasm can carry out various physiological activities only when the water content is high enough.

All biochemical reactions must be carried out with water as a medium or solvent. Water is one of the basic raw materials for photosynthesis, and it participates in various hydrolysis reactions and multiple reactions in respiration. The growth of plants usually causes the cells to elongate or expand by absorbing water.

When the turgor pressure decreases, growth slows down or stops. For example, a flash in the pan is to rely on the petals to quickly absorb water and expand and open; Morning glory blooms early in the morning and shrinks after sun exposure.

Some plants differentiate into special organs, and the turgor pressure can rise and fall reversibly due to the inflow and exit of water, so that the organs move rapidly. For example, when the air is dry and the water supply is insufficient, the vesicular cells lose water, so that the leaves are rolled into a cylindrical shape, and the water supply is restored again; The movement of the stomata is achieved by the expansion and contraction of the guard cells in response to changes in water conditions, thereby regulating the rate of water dispersion loss and maintaining the water balance of the plant. Conversely, some organs can only perform certain functions when they are dehydrated.

For example, the fruit pods of vine dills can burst only when they are dry, so that the seeds in them burst out; The dandelion seeds are ripe and dehydrated before they detach from their mothers and drift in the wind.

The cell of a plant is composed of a cell wall, a cell membrane, a cytoplasm, a cell fluid, a nucleus, and a cell wall and a large amount of water. In a drought environment, the water replenishment in the cells is less than the evaporation and loss of water, causing the cells to dry up and deform, resulting in the curling of corn leaves.

Poaceous plants such as corn have large cells with thin walls and large vacuoles in the upper epidermis, called vesicular cells or motile cells. When the leaf loses too much water during transpiration, the vesicular cells become relaxed, and the leaf can be folded or involuted to reduce transpiration; When transpiration decreases, they absorb water again and swell, so that the leaves are flattened again. During drought, the volume of vesicular cells shrinks, and the area of the upper epidermis shrinks, making the leaves roll into a tubular shape.

The lack of water and the curling of the leaves also slows down water evaporation.

Lack of moisture! shrunk.

So it is best not to spray this pesticide during this time period, so although this pesticide is said to be for plant fungal infection, but this period belongs to the state of collecting flowers and making pollen, so in this case, it is easy to affect sitting flowers and making flowers and fruits.

The leaves will undergo transpiration, and removing it can reduce excessive water loss and improve the survival rate.