Endosperm is a tissue found in the seeds of most plants. The endosperm commonly surrounds the embryo and serves as its nutrient store during germination and early life stages. Nutrients are stored in the form of starch, although oils and proteins are also common .

Origin

The origin of this presents two theories, one talks about the evolution of plants, that as they were changing and evolving, as a result of germination they began to produce a nutrient system in the embryonic sac to preserve the seed , but another theory says that this was added by scientists through a genetic modification of the seeds to give greater durability to this and prevent the seeds from not germinating or taking time to do so.

But in general, we are talking about a substance located inside the seed surrounding the embryo that will later become a plant in addition to nourishing and maintaining it also serves to protect it. This develops as the plant begins to mature, absorbing and storing all the necessary nutrients and then when the seed is detached from the plant begins to do its work. It is a generally transparent substance, but its weight, color and consistency varies depending on the type of plant from which it is extracted.

Characteristics

 This substance contained in plant seeds has the following characteristics:

• Transparent: is a fabric that does not have a specific color, it is usually transparent.
• Strong and durable: This fabric is really strong, it stays on the seed for a long time, feeding it and providing it with nutrients constantly over a long period of time.
• Different uses: This fabric can be used to make a variety of things, from flour to beer depending on the type of seed we are dealing with.
• Surrounds the embryo: this tissue is found inside the seed surrounding the embryo , covering it completely.
• Food: This tissue is full of nutrients, necessary for the maintenance and development of the seed and very useful for the plant in its first days.
• Spongy: when the seed is about to reach maturity, the endosperm already occupies 70% of the seed, reaching a considerable size in relation to the seed , becoming quite spongy.
• Various uses: This type of fabric, in addition to serving as food for the seed and its maturation, is also used to make many things and can even be consumed.

Importance

Plants are a very useful organism for humans, their reproduction through seeds is the most convenient and most used to preserve this species. In seeds we can find the endosperm, this substance is very important for the preservation of seeds , which already keeps them fed from the moment they are extracted from the plant until they are planted in their new place to give rise to another plant. This substance keeps them nourished and prevents them from wilting or the embryo inside them from dying. In addition to nourishing them and maintaining them in their seed stage, this nutritive tissue also presents nutrients to help good development after germination and for the seedling to begin to grow successfully.

Therefore, it is of considerable importance for agriculture and plant formation. This is also an important and fundamental ingredient in the production of some things in which it is generally not named much, thus underestimating its importance, for example, this is the main ingredient for making wheat flour, an important source of nutrition in the human diet, it is what provides the yeast or fermentation for beer, the creation of some corn flakes (popcorn) and is even often consumed like coconut , but it is still not known for sure because its importance is underestimated, attributing it totally to the seed when it is the endosperm that should have the leading role.

Substances stored in the endosperm

In the endosperm we can find many useful substances, which are:

• Oxygen: A large amount of oxygenis stored inside the seed , enough to allow the seed to survive for quite some time.
• Water:the endosperm is made up of a large part of water , this is to keep the seed hydrated for the entire time it is kept in reserve.
• Proteins:known as gluten in cereals, it is the layer responsible for providing the seed with all the necessary proteins, they have enormous nutritional value, comparable to that achieved in species of the animal kingdom.
• Fats:We can get a large amount of oil from some seeds, such as peanuts or walnuts .
• Carbohydrates:The presence of carbohydrates often occurs in the form of starch .
• Hemicelluloses:is a substance that forms in some seeds, generally in the seeds of a Panamanian palm tree, making it hard and resistant.

Classification of endosperm

This tissue can be classified into several types, depending on the way it was created and the type of plant in which it is found, these are:

According to creation

• Nuclear endosperm:this type of endosperm is produced when the central core of the seed separates into several smaller and more numerous nuclei. These do not have a cell wall that separates them at the beginning, but one can form later. They have many more nutrients, but the way they are distributed makes their distribution later.
• Cellular endosperm:This occurs when the central core of the seed is divided into two equal parts and these parts are divided by a uniform cell wall separating both halves. This facilitates the provision of nutrients to the seeds, but it is important to emphasize that this type of endosperm does not occur as regularly as nuclear endosperm.
• Helobial endosperm:this type of division is intermediate between the nuclear and the cellular, because when the first division of the seed nucleus takes place, it does so in half, presenting cell walls on both sides as in the case of the cellular endosperm, but once this division has taken place it will begin to divide into much smaller nuclei without the separation of the cell walls as in the case of the nuclear endosperm.

According to the type of plant

• Primary endosperm:The primary endosperm is formed in the seed long before fertilization, so it has no sexual significance. It occurs mainly in gymnosperm plants. It is produced by itself in the nucleus of the seeds.
• Secondary endosperm:This is generally found in angiosperm plants. It is a nutritive tissue that begins to form in the embryo sac shortly after fertilization. This tissue is full of nutrients and the embryo can absorb it all or leave a part to use as fertilization progresses.

Types of endosperm

Some of the most commonly used types of endosperm are:

Almond.

• Endosperm of wheat
• Endosperm of barley
• Endosperm of corn
• Endosperm of coconut
• Endosperm of rice
• Soybean endosperm

Seeds without endosperm

Despite the importance and usefulness of the endosperm, there are also some seeds that do not have it and still develop perfectly, since the nutrients they require are housed in cells that surround the embryo and in the cotyledons, which are the first leaves to grow on the plant. These also provide the embryo with the nutrients necessary for its growth and correct development. It is said that these seeds, lacking endosperm, are more evolved.

Peanut.

These seeds are commonly known as “ exendosperm seeds ”. Although it is important to mention that at the beginning of the birth of the seed always has endosperm, but in the case of these seeds, they absorb it as soon as the embryo begins to develop . Some examples of seeds without endosperm that we can cite are, the peanut seed , the walnut seed , the pea seed , some legumes and the bean which is a very famous grain in Chilean food. Although in these cases we can still find small remains of the endosperm that are not absorbed or eliminated completely by the plants, this endosperm is presented in the form of small cells that contain carbohydrates , but they are presented in such a minimal form that they cannot be used.