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17.1.3: Cohesion-Tension Theory

Ha, M. (n.d.). 17.1.3: Cohesion-Tension Theory. Libre Texts. https://bio.libretexts.org/Bookshelves/Botany/Botany_(Ha_Morrow_and_Algiers)/Unit_3%3A_Plant_Physiology_and_Regulation/17%3A_Transport/17.01%3A_Water_Transport/17.1.03%3A_Cohesion-Tension_Theory#:~:text=It%20creates%20negative%20pressure%20(tension,draw%2

According to the cohesion-tension theory, transpiration is the main driver of water movement in the xylem. It creates negative pressure at the leaf surface. Water from the roots is ultimately pulled up by this tension. Negative water potential draws water from the soil into the root hairs, then into the root xylem. Cohesion and adhesion draw water up the xylem. Transpiration draws water from the leaf through the stoma. Water potential becomes increasingly negative from the root cells to the stem to the highest leaves, and finally to the atmosphere. To continue reading, follow the link above.