This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Hendrix, D. L. Articles by Grange, R. I. Search for Related Content PubMed PubMed Citation Articles by Hendrix, D. L. Articles by Grange, R. I. Agricola Articles by Hendrix, D. L. Articles by Grange, R. I.

Metabolism and Enzymology

Carbon Partitioning and Export from Mature Cotton Leaves

Western Cotton Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Phoenix, Arizona 85040, Department of Plant Physiology, Institute of Horticultural Research, Worthing Road, Littlehampton, West Sussex, BN17 6LP, United Kingdom

The partitioning of carbon in intact, mature cotton (Gossypium hirsutum L.) leaves was examined by steady-state ¹⁴CO₂ 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 (r = 0.934) and with nocturnal leaf respiration (r = 0.954). 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.

This article has been cited by other articles:

				E. D. Leonardos, B. J. Micallef, M. C. Micallef, and B. Grodzinski Diel patterns of leaf C export and of main shoot growth for Flaveria linearis with altered leaf sucrose-starch partitioning J. Exp. Bot., March 1, 2006; 57(4): 801 - 814. [Abstract] [Full Text] [PDF]

				B. Grodzinski, J. Jiao, V. L. Knowles, and W. C. Plaxton Photosynthesis and Carbon Partitioning in Transgenic Tobacco Plants Deficient in Leaf Cytosolic Pyruvate Kinase Plant Physiology, July 1, 1999; 120(3): 887 - 896. [Abstract] [Full Text]