The phloem tissue is responsible for the transport of organic constituents in plants. It is made up of several different components that work together to facilitate the conduction of sugars and amino acids from source tissues to sink tissues where they are consumed or stored. The constituents of phloem are:
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Sieve tubes: These are perforated-walled tubular cells that are responsible for the transport of sugars and other organic compounds.
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Companion cells: These are specialized parenchyma cells that are closely associated with sieve tubes and are responsible for maintaining their metabolic functions.
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Phloem fibers: These are long, flexible sclerenchyma cells that provide tensile strength to the phloem tissues.
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Phloem parenchyma: These are thin-walled parenchyma cells that are involved in the storage of organic compounds and provide mechanical support to the phloem tissues.
These four types of constituents make up the phloem tissue in plants.
