ABSTRPT.014 - Jim Bidlack - BIO 5354/4354 PLANT ANATOMY...

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Jim Bidlack - BIO 5354/4354 PLANT ANATOMY Lecture 14 - I. Water potential A. Water potential ( Ø ) = pressure potential ( Ø p) + osmotic potential ( Øð ) + matrix potential ( Ø m) 1. Water potential - a measure used to predict the direction of water flow (from high to low) a) b) Osmotic potential - can be used to regulate turgor - regulates plant water movement c) Matrix potential - force with which water is held to plants by adsorption and capillarity II. Water and mineral absorption by roots A. Absorption of water by roots 1. Driven by transpiration - negative pressure in xylem draws water in through free space - water must move through living cells of endodermis 2. Root pressure (driving force when transpiration is low - high humidity) a) Solutes (sugars) built up in roots cause an osmotic drive of water from surrounding media solution to inner root (i.e., water moves from higher potential
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This note was uploaded on 03/27/2012 for the course BIO 5354 taught by Professor Bidlack during the Fall '11 term at University of Florida.

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