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Plant Physiology logoLink to Plant Physiology
. 1995 Feb;107(2):507–514. doi: 10.1104/pp.107.2.507

Photosynthetic Carbon Metabolism and Translocation in Wild-Type and Starch-Deficient Mutant Nicotiana sylvestris L.

D R Geiger 1, W J Shieh 1, X M Yu 1
PMCID: PMC157154  PMID: 12228378

Abstract

A high rate of daytime export of assimilated carbon from leaves of a starch-deficient mutant tobacco (Nicotiana sylvestris L.) was found to be a key factor that enabled shoots to grow at rates comparable to those in wild-type plants under a 14-h light period. Much of the newly fixed carbon that would be used for starch synthesis in leaves of wild-type plants was used instead for sucrose synthesis in the mutant. As a result, export doubled and accumulation of sucrose and hexoses increased markedly during the day in leaves of the mutant plants. The increased rate of export to sink leaves appeared to be responsible for the increase in the proportion of their growth that occurred during the day compared to wild-type plants. Daytime growth of source leaves also increased, presumably as a result of the increased accumulation of recently assimilated soluble carbon in the leaves. Even though starch accumulation did not occur in the leaves of mutant plants, nearly all the sugar that accumulated during the day was exported in the period of decreasing irradiance at the end of the diurnal light period. Changes in carbon allocation that occurred in leaves of wild-type and mutant plants near the end of the light period appeared to result from endogenous diurnal regulation associated with the day-night transition.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Caspar T., Huber S. C., Somerville C. Alterations in Growth, Photosynthesis, and Respiration in a Starchless Mutant of Arabidopsis thaliana (L.) Deficient in Chloroplast Phosphoglucomutase Activity. Plant Physiol. 1985 Sep;79(1):11–17. doi: 10.1104/pp.79.1.11. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Doman D. C., Geiger D. R. Effect of Exogenously Supplied Foliar Potassium on Phloem Loading in Beta vulgaris L. Plant Physiol. 1979 Oct;64(4):528–533. doi: 10.1104/pp.64.4.528. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Fondy B. R., Geiger D. R. Diurnal Pattern of Translocation and Carbohydrate Metabolism in Source Leaves of Beta vulgaris L. Plant Physiol. 1982 Sep;70(3):671–676. doi: 10.1104/pp.70.3.671. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Fondy B. R., Geiger D. R. Diurnal changes in allocation of newly fixed carbon in exporting sugar beet leaves. Plant Physiol. 1985 Aug;78(4):753–757. doi: 10.1104/pp.78.4.753. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fondy B. R., Geiger D. R., Servaites J. C. Photosynthesis, Carbohydrate Metabolism, and Export in Beta vulgaris L. and Phaseolus vulgaris L. during Square and Sinusoidal Light Regimes. Plant Physiol. 1989 Feb;89(2):396–402. doi: 10.1104/pp.89.2.396. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Geiger D. R., Fondy B. R., Tucci M. A. A Method for Calculating Sucrose Synthesis Rates throughout a Light Period in Sugar Beet Leaves. Plant Physiol. 1988 Jul;87(3):776–780. doi: 10.1104/pp.87.3.776. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Goldschmidt E. E., Huber S. C. Regulation of photosynthesis by end-product accumulation in leaves of plants storing starch, sucrose, and hexose sugars. Plant Physiol. 1992 Aug;99(4):1443–1448. doi: 10.1104/pp.99.4.1443. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hanson K. R., McHale N. A. A Starchless Mutant of Nicotiana sylvestris Containing a Modified Plastid Phosphoglucomutase. Plant Physiol. 1988 Nov;88(3):838–844. doi: 10.1104/pp.88.3.838. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Huber S. C. Biochemical Mechanism for Regulation of Sucrose Accumulation in Leaves during Photosynthesis. Plant Physiol. 1989 Oct;91(2):656–662. doi: 10.1104/pp.91.2.656. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Li B., Geiger D. R., Shieh W. J. Evidence for circadian regulation of starch and sucrose synthesis in sugar beet leaves. Plant Physiol. 1992 Aug;99(4):1393–1399. doi: 10.1104/pp.99.4.1393. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Trethewey R. N., ap Rees T. A mutant of Arabidopsis thaliana lacking the ability to transport glucose across the chloroplast envelope. Biochem J. 1994 Jul 15;301(Pt 2):449–454. doi: 10.1042/bj3010449. [DOI] [PMC free article] [PubMed] [Google Scholar]

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