pholem is a food conducting tissue in aplant.it is made up to of four component :1.sieve tubes2.companion cells 3.pholem panechyma4.pholem fibrez

Constituents of Phloem
Phloem is a vital tissue in vascular plants responsible for the transport of nutrients, particularly the products of photosynthesis. It consists of several key components that work together to facilitate this function.
1. Sieve Elements
- These are specialized cells that form the main conducting elements of phloem.
- Sieve elements have perforated end walls (sieve plates) that allow for the flow of sap.
- They are living cells but lack a nucleus and most organelles, relying on companion cells for metabolic support.
2. Companion Cells
- Companion cells are closely associated with sieve elements and play a crucial role in their functioning.
- They contain a nucleus and organelles, providing the necessary support and metabolic functions for the sieve elements.
- They help in the loading and unloading of sugars and other substances into and out of the sieve elements.
3. Phloem Parenchyma
- These are living cells that perform various functions, including storage and lateral transport.
- Phloem parenchyma cells can store starch, oils, or other substances, contributing to the plant’s overall metabolism.
- They also help in wound healing and can differentiate into other cell types as needed.
4. Phloem Fibers
- These are supportive cells that provide structural strength to the phloem.
- Composed of long, slender cells, phloem fibers contribute to the rigidity of the plant.
- Their presence is vital for maintaining the integrity of the plant as it grows and withstands environmental stresses.
5. Phloem Sap
- Phloem sap is the fluid transported through the phloem, primarily composed of water, sugars (mostly sucrose), hormones, and nutrients.
- It plays a critical role in transporting energy from photosynthetic tissues to non-photosynthetic parts of the plant.
Understanding these constituents is essential for grasping how plants distribute nutrients and maintain their physiological processes.