Assimilate movement in Ipomoea Tricolor source leaf tissue
Autoradiographs of /sup 14/CO/sub 2/-labelled Ipomoea tricolor leaf discs show that the relay of /sup 14/C-assimilates from the mesophyll to the minor veins is unaffected by pretreatment with 2 mM PCMBS. In contrast, pretreatment of discs at pH 9 results in full or nearly complete inhibition of movement of /sup 14/C-assimilates to the veins, in agreement with previous findings for the symplastic movement of microinjected fluorescent dye. Uptake of exogenously supplied (/sup 14/C) sucrose into Ipomoea leaf discs or isolated mesophyll cells is inhibited by PCMBS or pH 9 pretreatments. However, autoradiographs of pretreated leaf discs show that the radioactivity from accumulated (/sup 14/C)sucrose is always predominantly associated with the minor veins, suggesting that direct uptake by these tissues does occur but may simply represent the operation of general retrieval mechanisms. In addition, these data also suggest that the symplastic relay of solutes, derived within or taken up by mesophyll cells, to the minor veins may contribute significantly to the autoradiographic image produced by leaf discs labelled with /sup 14/CO/sub 2/ or with exogenously supplied (/sup 14/C)-sucrose.
- Research Organization:
- Univ. of California, Riverside
- OSTI ID:
- 5849182
- Report Number(s):
- CONF-8707108-
- Journal Information:
- Plant Physiol., Suppl.; (United States), Journal Name: Plant Physiol., Suppl.; (United States) Vol. 83:4; ISSN PPYSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AUTORADIOGRAPHY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DISACCHARIDES
INHIBITION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEAVES
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
ORNAMENTAL PLANTS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PLANTS
SACCHARIDES
SACCHAROSE
SOLUTES
TRACER TECHNIQUES
TRANSLOCATION
UPTAKE