Carbon partitioning and export from mature cotton leaves

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Plant Physiology; (United States)

DOI:https://doi.org/10.1104/pp.95.1.228· OSTI ID:5741968

Hendrix, D L ^[1]; Grange, R I ^[2]

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1. Dept. of Agriculture, Phoenix, AZ (United States)
2. Inst. of Horticultural Research, Sussex (United Kingdom)

The partitioning of carbon in intact, mature cotton (Gossypium hirsutum L.) leaves was examined by steady-state {sup 14}CO{sub 2} labeling. Plants were exposed to dark periods of varying lengths, followed by similar illuminated labeling periods. These treatments produced leaves with a range of starch and soluble sugar contents, carbon exchange, and carbon export rates. Export during the illuminated periods was neither highly correlated with photosynthesis nor was export during the illuminated periods significantly different among the treatments. In contrast, the rate of subsequent nocturnal carbon export from these leaves varied widely and was found to be highly correlated with leaf starch content at the end of the illumination period and with nocturnal leaf respiration. Leaves which had accumulated the highest levels of starch (about 275 micrograms per square centimeter) by the end of the illumination period exhibited nocturnal export rates very similar to those during the daylight hours. Leaves which accumulated starch to only 50 to 75 micrograms per square centimeter virtually ceased nocturnal carbon export. For leaves with starch accumulations of between 50 and 275 micrograms per square centimeter, nocturnal export was directly proportional to leaf starch at the end of the illumination period. After the nocturnal export rate was established, it continued at a constant rate throughout the night even though leaf starch and sucrose contents declined.

• OSTI ID: 5741968
• Journal Information: Plant Physiology; (United States), Journal Name: Plant Physiology; (United States) Vol. 95:1; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COTTON PLANTS
DISACCHARIDES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEAVES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
METABOLISM
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
POLYSACCHARIDES
REAGENTS
RESPIRATION
SACCHARIDES
SACCHAROSE
STARCH
SYNTHESIS
TRACER TECHNIQUES