HORT 1130 Lecture Notes - Lecture 7: Casparian Strip, Suberin, Xylem
14 Mar 2016
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Document Summary
Anything that increases the gradient is driven by outside substances. Spraying the leaves is trying to decrease the humidity outside the plant. Sometimes transpiration is greater than the ability of the plant to take up water, one of the outcomes from this is wilting. You need to know you plant, so you can see signs of wilting. If there is damage to the membrane the plant cannot recover, there is to much internal damage. Sometimes plants will wilt under well watered conditions, on a hot windy day because transpiration will exceed the ability to take up water fast enough. Water getting into the plant is a passive process but mainly a active process. Casparian strip, made of a material called suberin, this coats the cells in the outer part of the epidermis. Water can only enter through the cell membrane, it can control what goes in and what goes out. There is no suberin around the root hairs.
