Pressure probe and isopiestic psychrometer measure similar turgor

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.83.3.592· OSTI ID:6545975

Nonami, H; Boyer, J S; Steudle, E

Turgor measured with a miniature pressure probe was compared to that measured with an isopiestic thermocouple psychrometer in mature regions of soybean (Glycine max (L.) Merr.) stems. The probe measured turgor directly in cells of intact stems whereas the psychrometer measured the water potential and osmotic potential of excised stem segments and turgor was calculated by difference. When care was taken to prevent dehydration when working with the pressure probe, and diffusive resistance and dilution errors with the psychrometer, both methods gave similar values of turgor whether the plants were dehydrating or rehydrating. This finding, together with the previously demonstrated similarity in turgor measured with the isopiestic psychrometer and a pressure chamber, indicates that the pressure probe provides accurate measurements of turgor despite the need to penetrate the cell. On the other hand, it suggest that as long as precautions are taken to obtain accurate values for the water potential and osmotic potential, turgor can be determined by isopiestic psychrometry in tissues not accessible to the pressure probe for physical reasons.

• Research Organization: Univ. of Illinois, Urbana
• DOE Contract Number: FG05-84ER13273
• OSTI ID: 6545975
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 83:3; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOLOGICAL FUNCTIONS
COMPARATIVE EVALUATIONS
DIFFUSION
ERRORS
FUNCTIONS
GLYCINE HISPIDA
LEGUMINOSAE
MEASURING INSTRUMENTS
MEASURING METHODS
MICROORGANISMS
OSMOSIS
PLANT CELLS
PLANT STEMS
PLANTS
PRESSURE GAGES
PRESSURE MEASUREMENT
RHIZOBIUM