THE EFFECT OF WATER MOVEMENT ON ION MOVEMENT INTO THE XYLEM OF TOMATO ROOTS

Technical Report · Mon Jan 01 04:00:00 EST 1962

OSTI ID:4070160

Lopushinsky, W

The relation between water movement and salt movement through tomato roots was studied. Water movement through detopped root systems was increased by increasing the hydrostatic pressure of the solution surrounding the roots. The rate of salt movement into the root xylem was determined by measuring the volume and salt concentration of exudate collected from the stumps. Comparisons were made of amounts of salt moved into the root xylem when water was moved under pressure, with amounts moved by active transport in the absence of external pressure. Application of pressure increased the amount of P, Ca, and total salts moved into the root xylem, but not in proportion to the increased rates of water movement. At 30 lb/in./sup 2/, the amount of ions moved into the root xylem was 2.0 to 2.4 times the amount moved by active transport in the absence of pressure. The salt concentration of exudates obtained under pressure usually was less than the concentration of the external solution. Treatment of roots with sodium azide initially reduced the rates of both water and phosphorus movement to about 10% of the control rates. Longer exposure to azide resulted in an increase in the rates of both water and phosphorus movement. Possible reasons for the increased rate of salt movement under pressure are discussed. (auth)

• Research Organization: Duke Univ., Durham, N.C.
• NSA Number: NSA-18-021723
• OSTI ID: 4070160
• Report Number(s): TID-18877
• Country of Publication: United States
• Language: English

Related Subjects

CALCIUM
DIFFUSION
GENERAL AND MISCELLANEOUS
IONS
PHOSPHORUS
PLANTS
PRESSURE
QUANTITY RATIO
ROOTS
SALTS
SOLUTIONS
TISSUES
WATER