Jan. 24th-Test 1

Jan. 24th-Test 1 - plasmodesmata to the xylem B.4. B.5....

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
I. Plant H 2 O Movement and Water Deficit A. Movement from the soil into the root xylem and toward the leaf A.1. As water in the Xylem moves toward the mesophyll cells, a tension develops in the water column and Psi of the xylem decreases below that of the outer Parenchyma cells of the root. A.2. Water moves from the outer parenchyma cells of the root to the xylem, so Psi of the root is less than Psi of the soil. A.3. Therefore, evaporation of water from the mesophyll cells and its escape via the stomata during the day is the main reason for the development of a low Psi in the plant Water only moves into the plant when Psi of the plant is less than the Psi of the soil. B. Root H 2 O Movement B.1. Root Anatomy- young roots of a true are the only roots absorbing water and nutrients B.2. The presence of the endodermis forces water to move into living cells of the epidermis and cortex parenchyma B.3. Then movement from parenchyma cell to parenchyma cell via
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: plasmodesmata to the xylem B.4. B.5. Plasmodesmata are strands of protoplasm connecting parenchyma cells. C. Water Deficit Stress C.1. Why study water movement and water-deficit responses? Most plant productivity is water-limited Water availability may decrease in may agricultural areas in the future The human population is still growing C.2. Stages of Water Deficit Mild Stress- No wilting, frequent in afternoons C.2. .a. Problems very low growth Moderate Stress- some afternoon wilting C.2. .a. Problems reduction in photosynthesis by 50%, no growth in the afternoon, but still at night Severe stress- wilting most of the day C.2. .a. Problems no growth and low photosynthesis occurrences C.2. .b. Membrane damage in Parenchyma cells and protein denaturation are two things that will kill the...
View Full Document

Page1 / 2

Jan. 24th-Test 1 - plasmodesmata to the xylem B.4. B.5....

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online