Plasmadesmatal frequency, apoplast-symplast ratio, and photosynthetic transfer in grapefruit juice vesicles. [Citrus paradisi Macf]

Conference · Tue Apr 01 00:00:00 EST 1986 · Plant Physiol., Suppl.; (United States)

OSTI ID:5018298

Koch, K E; Lowell, C A; Avigne, W T

Structure and function were examined in phloem-free vesicles and vesicle stalks of grapefruit (Citrus paradisi Macf.) by light and electron microscopy and /sup 14/C-photosynthate transport in intact and dissected tissues. Plasmodesmatal frequencies were approximately 0.3 to 0.5 ..mu..m/sup -1/ cell wall interface (3 to 5 ..mu..m/sup -2/), less than that of known secretory structures but similar to root parenchyma. Cell wall or apoplast comprised 18 to 24% of the total cross-sectional area of the vesicle stalk. The mass of total photosynthate transfer through individual vesicle stalks was ca. 0.5 ..mu..g C h/sup -1/ and rate of /sup 14/C-movement 0.1 to 0.4 mm h/sup -1/. Transport continued in rows of vesicles dissected in association with a vascular bundle. If isolated from fully-expanded fruit, translocation was similar for systems with frozen vs. non-frozen vesicle stalks. Similar freezing treatment decreased transport in vesicles from younger fruit. Symplastic and apoplastic pathways may therefore both operate in this system.

• Research Organization: Univ. of Florida, Gainesville
• OSTI ID: 5018298
• Journal Information: Plant Physiol., Suppl.; (United States), Vol. 80:4; Conference: Annual meeting of the American Society of Plant Physiologists, Baton Rouge, LA, USA, 8-12 Jun 1986; Other Information: C45.00*
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GRAPEFRUITS
BIOLOGICAL PATHWAYS
PLANT CELLS
CYTOLOGY
CARBON 14 COMPOUNDS
CELL WALL
ELECTRON MICROSCOPY
OPTICAL MICROSCOPY
PHOTOSYNTHESIS
BIOLOGY
CELL CONSTITUENTS
CHEMICAL REACTIONS
FOOD
FRUITS
LABELLED COMPOUNDS
MICROSCOPY
PHOTOCHEMICAL REACTIONS
SYNTHESIS
550800* - Morphology