Transfer cell wall ingrowths and vein loading characteristics in pea leaf discs. [Pisum sativum]
Transfer cell wall ingrowths are thought to increase transport capacity by increasing plasmalemma surface area. Leaf minor vein phloem transfer cells presumably enhance phloem loading. In Pisum sativum cv. Little marvel grown under different light regimes (150 to 1000 ..mu..mol photons m/sup -2/ sec/sup -1/) there is a positive correlation between light intensity and wall ingrowth area in phloem transfer cells. The extent of ingrowth and correlation to light intensity is greatest in minor veins, decreasing as vein size increases. Vein loading was assayed by floating abraded leaf discs on /sup 14/C-sucrose (10 mM). There is a positive correlation between uptake and transfer cell wall area, although the latter increased more than the former. The difference in uptake is stable throughout the photoperiod, and is also stable in mature leaves for at least four days after plants are transfered to a different light intensity. Sucrose uptake is biphasic. The saturable component of uptake is sensitive to light intensity, the Km for sucrose is negatively correlated to light intensity, while V/sub max/remains unchanged.
- Research Organization:
- Cornell Univ., Ithaca, NY
- OSTI ID:
- 6073213
- Report Number(s):
- CONF-8707108-; TRN: 87-037212
- Journal Information:
- Plant Physiol., Suppl.; (United States), Vol. 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBOHYDRATES
TRANSLOCATION
CELL WALL
MORPHOLOGY
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CARBON 14 COMPOUNDS
CELL MEMBRANES
LEAVES
PISUM
SACCHAROSE
TRACER TECHNIQUES
UPTAKE
VISIBLE RADIATION
BACTERIA
CELL CONSTITUENTS
DISACCHARIDES
ELECTROMAGNETIC RADIATION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LEGUMINOSAE
MEMBRANES
MICROORGANISMS
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PLANTS
RADIATIONS
REACTION KINETICS
RHIZOBIUM
SACCHARIDES
550201* - Biochemistry- Tracer Techniques
551001 - Physiological Systems- Tracer Techniques