Biology 2601A/B Lecture Notes - Lecture 14: Soil Plant Atmosphere Continuum, Casparian Strip, Palisade Cell
13 Feb 2018
School
Department
Course
Professor
Document Summary
Lecture 14 roots: today = talking about water and nutrient uptakes in plants, and particularly looking at roots and root systems, talked about water transport, drought stress and heat stress in plans but looking at the consequences. If you"re not absorbing enough water as a plant, they will get wilted and they lose that turgor pressure. They might start to angling their leaves, which is a mechanism in avoiding radiation absorption. If you don"t do this and the drought persists, then you can mortality. We are see this increasing in forest. Heat stress coupled with ongoing drought stress is leading to mortality. Water is pulled from soil into roots and up to leaves through the soil plant atmosphere continuum: cohesion-tension theory. Negative water potential generated inside the leaf at the mesophyll cell wall. Inside the xylem, the water is moving along the water pressure gradient. You have your palisade mesophyll cells and your substomatal cells where photosynthesis is occurring.
