Role of turgor pressure and solute transport in plant cell growth: Progress report
Plant cell expansion involves simultaneous water absorption, solute uptake, and wall relaxation and synthesis. Our studies have shown that water absorption by the growing stems of pea (Pisum sativum L.) and other young seedlings is fast and is regulated primarily by wall yielding, which generates the lower water potential necessary for water absorption. Our current focus is on the nature of wall yielding, its dependence on cell turgor pressure, and the mechanism by which cell turgor is maintained in expanding cells. We have developed new relaxation methods to study wall yielding. With the pressure-probe technique we find that wall yielding in excised growing tissues is proportional to cell turgor pressure and exhibits a definite yield threshold. With the pressure-block method we can measure relaxation in intact growing tissues and find that such tissues show more complicated growth and relaxation responses than excised ones. Rapid feedback-regulation of growth is apparent from the pressure-block experiments. With these methods we have examined how drought-stress, light and growth retardants modulate stem elongation. The last two agents acts exclusively on cell wall yielding properties. With droughted pea plants, inhibition is partly through reduced cell turgor pressure and partly through reduced wall relaxation. Drought appears to alter feedback-regulation of cell expansion. Experiments are currently underway to characterize such regulation. In a related line of study we find close correspondence between rates of solute uptake from the phloem and rates of cell expansion. Work is underway to determine the nature of such coupling. 3 refs., 4 figs.
- Research Organization:
- Pennsylvania State Univ., University Park (USA). Dept. of Biology
- DOE Contract Number:
- FG02-84ER13179
- OSTI ID:
- 6462245
- Report Number(s):
- DOE/ER/13179-2; ON: DE89006080
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Role of turgor pressure and solute transport in plant cell growth: Progress report
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Related Subjects
60 APPLIED LIFE SCIENCES
CELL WALL
PHYSIOLOGY
TRANSLOCATION
PRESSURE MEASUREMENT
APHIDS
GLYCINE HISPIDA
PISUM
PLANT GROWTH
PROGRESS REPORT
SEEDLINGS
ANIMALS
ARTHROPODS
BACTERIA
CELL CONSTITUENTS
DOCUMENT TYPES
GROWTH
HEMIPTERA
INSECTS
INVERTEBRATES
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MICROORGANISMS
PLANTS
RHIZOBIUM
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)
553000 - Agriculture & Food Technology