When winter comes, it's cold. We are smart enough to create an environment for us to spend the winter safely. However, the animals we are familiar with, such as dogs, cats and rabbits, will grow a lot of thin and thick fluff in autumn. In winter, the thick fluff will cover the body to let them spend the cold winter. Do you know how plants live through the winter?
How do plants survive the winter - Plant Science
1: To lose one's burden -- to lose one's leaf
Plants are very sensitive to the change of temperature, so when winter comes, the decrease of temperature will lead to various chemical reactions in their bodies. The most common expression of plants is that they lose their leaves. To avoid frost damage, plants often lose some of their own burden, the most typical is the leaves.
When the autumn wind blows, as the day gets shorter, the plant senses the drop of temperature, so it begins to transport the nutrients in the leaves to the branches. At this time, a large amount of abscisic acid is produced on the leaves, which causes the leaves to fall off. At the same time, this abscisic acid is also a dormant element. After receiving the orders from the plants, it is transported to the tip and lateral buds of the branches, so the growth point of the plants They are inhibited, breathing is weakened, metabolism is stopped, and they go to sleep. In winter, plants are smart to "carry" the protein and starch hidden in the body. Under the action of enzymes, these proteins and starch will be hydrolyzed into soluble amino acids and sugars, so as to increase the concentration of plant cell fluid, making it not easy to freeze, thus enhancing the ability of cold resistance.
2: Conditioning the body -- regulating energy consumption and water content
In the body of plants, there are actually a series of physiological reactions. Like animals, they will reduce energy consumption activities to the lowest level, and make their own cold resistance to the strongest level, so as to adapt to the rapid changes in the external environment. The cold resistance of plants is very strong, such as conifers, which can resist the freezing temperature of minus 30-40 ℃ in winter. When winter comes, plants will reduce the absorption of water, so that their water content will gradually decline. Therefore, most of the plants we see in winter are withered, which is the self-protection measures they take to squeeze out the water in their bodies, so as to protect them from freezing in winter.
Evergreen pine and cypress
Why are trees like pines and cypresses still green in winter?
Conifers and cypresses have unique leaf structure. Their epidermis cell wall is relatively thick. The stomata of lower epidermis cell can be closed automatically, forming cuticle, and building "iron wall" to avoid moisture emission, so as to resist winter cold. At the same time, due to the continuous decrease of temperature, the life activities of roots are weakened, the water content in their bodies is gradually reduced, and the concentration of cell fluid is gradually increased, so as to avoid the possibility of cell freezing, so that they can safely survive the winter (it seems to be very advanced, which is obviously evolution).
Of course, in order to preserve the "fire", different plants have gradually formed their own winter ways. For example, most annual plants store the products of photosynthesis in seeds before frost. These seeds are carried by wind and other objects, and spread to all places for offspring reproduction. And those perennial plants, such as grasses and weeds, will store the nutrients of photosynthetic products in their own roots for winter before winter comes, and when the next spring is warm, they will re accumulate the strength to reproduce.
There are also some plants that do not store nutrients in seeds or roots, but in vivo, to increase cell concentration and reduce free water to resist the winter cold, such as winter wheat, rape and other biennial plants, which accumulate a lot of sugar before winter to resist the invasion of cold. I don't know if you have noticed that frozen potatoes or sweet potatoes often taste sweeter than ordinary ones. Why? This is because they accumulate a lot of sugar in winter.
Do you think it's amazing after reading this. By the way, this is our magical nature. I hope you will continue to pay attention to the plant home, and we will continue to bring you interesting articles about plants.