In the course of botany, many different concepts are studied. One of them is the endosperm. What is it, what functions in a plant does this structure perform? You will find the answer to these and other questions in this article.
The endosperm is part of the fetus
People have long been amazed at the ability of a tiny seed to give rise to a whole organism. It turns out that this is due to its unique structure. The seed consists of the germinal root, stem, bud and leaflet. These embryonic structures are surrounded by nutritious connective tissue. She is the endosperm. Outside, the seed has additional protection - the peel.
This term comes from two Greek words "endo" - inside, "sperm" - a seed. In fact, this is a supply of substances necessary for the development of embryonic tissues.
The value of nutrients
The endosperm is the tissue that forms during fertilization. In chemical composition, it is a combination of starch carbohydrate, proteins and vegetable oils. Therefore, a person uses seeds as a source of energy and vitamins. But they retain useful properties only in their raw form. During heat treatment, the destruction of macromolecules of organic substances occurs.
So, half a glass of pumpkin seeds will provide the body with half the daily norm of proteins and B vitamins, prevent the formation of kidney stones and relieve parasites. And pomegranate is a real elixir of youth. Saturating the blood with antioxidants, it prevents the aging process.
Gymnosperm endosperm
Nourishing tissue of plants can be primary and secondary. In gymnosperms, endosperms are formed even before the process of fusion of gametes - fertilization. It develops from a megaspore, which is a mother cell with a haploid set of chromosomes. The primary endosperm is the tissue that forms in the ovule. As a result of its development, the formation of a female growth, or gametophyte, occurs.
Double fertilization of plants
In the seeds of angiosperms, the endosperm is formed during fertilization. During this process, two sperm are involved, which are located in the anthers of the stamens. Pestle ovary contains one female gamete and central germ cell. Fertilization takes place here. One sperm fuses with the egg, forming a seed embryo. The other connects with the germ cell. The result of the latter process is the endosperm. This type of formation is called secondary. The endosperm is located around the embryo, warming and nourishing it, creating conditions for seed germination.
How is it formed?
The endosperm is formed in two ways. In the first case, the fertilized nucleus of the embryo sac is divided many times. The resulting structures are located along its walls. This type of endosperm formation is called nuclear. In this case, the nutrient tissue of the seeds is liquid. For example, coconut milk.
But in most angiosperms, nuclear fission occurs after nuclear fission. It changes the state of aggregation of nutrient tissue. At the same time, cells are formed during each division. So, if you collect the fruits of corn during the period of nuclear fission, it will be juicy and sweet. What follows is the conversion of simple carbohydrates to polysaccharides. This chemical transformation accompanies cell division.
So, the endosperm, which is the nutrient of the seed germ, performs the most important functions. These include providing the embryo with energy, vitamins and minerals, transporting solutions of mineral substances from an adult plant. The regulation of the process of differentiation of embryonic cells into organs, which occurs due to endosperm cytokinins, is also important.