What is brewed sap?

The sap is the fluid that transports water and nutrients in vascular plants. Its function could be made analogous to the function of blood circulation in animals. According to the composition and specific function, two types can be distinguished: the raw sap and the elaborated SAP.

Raw sap is made up of water, minerals and other nutrients absorbed from the ground. It may also contain other substances, such as phytoregulators and phytohormones. Raw sap flows through the xylem, a type of plant vascular tissue, and distributes water and nutrients to the green organs where the flat plant performs photosynthesis. The flow is unidirectional from the roots to the aerial part of the plant.

Processed sap is also a water-based fluid, like raw sap, but instead of being rich in minerals, it is rich in sugars and smaller amounts of other organic compounds such as amino acids, vitamins, phytoregulars, and organic acids.

The elaborated sap is transported by the phloem, another type of plant vascular tissue. Unlike xylem, phloem can flow bidirectionally, transporting nutrients to all parts of the plant that need them, both to photosynthetic organs and to roots and other non-photosynthetic organs.

formation and flow

The elaborated sap is formed from the raw sap. The raw sap is formed in the roots and reaches the photosynthetic organs, mainly leaves. Here, the photosynthetic cells absorb the water and minerals they need from the crude sap and secrete simple carbohydrates, the majority being saccharosealthough it depends on the species. For example, in some species of cucurbits the main phloem sugar is raffinose.

The secretion of sugars is carried out in the sieve tubes of the phloem, where their high concentration creates osmotic pressure which draws water from the raw sap and thus forms the phloem fluid known as processed sap.

The elaborated sap flows transporting the sugars throughout the plant. The sense of movement is produced, in other causes, by the mass flow in favor of the sugar concentration gradient, that is, from the areas of higher concentration (source organs) to the areas of lower concentration (consumer organs or sinks).

At the beginning of the growth periods, generally during spring, the areas with the highest concentration of sugars are the storage organs, for example tubers and roots, while the shoots are areas that consume large amounts of carbohydrates. In these periods, the phloem can flow from the roots to the aerial part of the plant.

In the development periods, when the leaves are already the main source of sugars. the phloem will flow mainly to the roots, storage organs, and growth meristems. During the reproductive periods, the phloem carries the sugars to the fruits, which in these periods are the main areas demanding carbohydrates.

In addition to transporting nutrients, the elaborated sap also transports hormones and other phytoregulators that act as chemical signals with which the different organs of the plant communicate to regulate physiological processes.

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