👉 Sap fluid, also known as phloem sap, is a complex liquid transported through the vascular tissue of plants, primarily in angiosperms (flowering plants). It serves as a crucial medium for the distribution of photosynthetic products, such as sugars, amino acids, and other organic compounds, from source tissues (like leaves) to sink tissues (such as roots, fruits, and growing shoots). This process, known as translocation, is driven by a pressure gradient created by the active loading of sugars into the phloem sieve tubes in source tissues, which lowers their water potential and causes water to flow out, creating a high-pressure stream. This sap then moves through the sieve tubes to sink tissues, where sugars are unloaded and utilized for growth, storage, or other metabolic processes. The sap also plays a role in signaling and defense mechanisms within the plant.
