Chloroplast osmotic adjustment allows for acclimation of photosynthesis to low water potentials

Conference · Wed Apr 01 04:00:00 EST 1987 · Plant Physiol., Suppl.; (United States)

OSTI ID:5520518

Gupta, A S; Berkowitz, G

Previously in this laboratory, studies indicated that photosynthesis (PS) of chloroplasts isolated from spinach plants which underwent osmotic adjustment during in situ water deficits was inhibited less at low osmotic potentials (Psi/sub s/) in vitro than PS of plastids isolated from well watered plants. In this study, an attempt was made to determine if chloroplast acclimation to low Psi/sub s/ was associated with in situ stromal solute accumulation. During a 14d stress cycle, in situ stromal volume was estimated by measuring (using the /sup 3/H/sub 2/O, /sup 14/C-sorbitol silicon oil centrifugation technique) the stromal space of plastids in solutions which had the Psi/sub s/ adjusted to the leaf Psi/sub s/. During the first lid of the cycle, stromal volume did not decline, despite a decrease of over 20% in the leaf RWC. After this time, stromal volume dropped rapidly. In situ stromal Psi/sub s/ was also estimated during a stress cycle. These studies indicated that stromal Psi/sub s/ was lowered by net solute accumulation. The data presented in this report suggest that chloroplast acclimation to low Psi/sub s/ may involve stromal solute accumulation and volume maintenance during cell water loss.

• Research Organization: Rutgers Univ., New Brunswick, NJ
• OSTI ID: 5520518
• Report Number(s): CONF-8707108-
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 83:4
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL ACCUMULATION
BIOLOGICAL ADAPTATION
BIOLOGICAL STRESS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CENTRIFUGATION
CHEMICAL REACTIONS
CHLOROPLASTS
DIURETICS
DRUGS
ENERGY
FOOD
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MONOSACCHARIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
POTENTIAL ENERGY
PRESSURE DROP
SACCHARIDES
SEPARATION PROCESSES
SOLUTES
SORBITOL
SPINACH
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VEGETABLES
WATER