Abstract
Studies conducted in controlled environments indicate that daylength affects the proportion of photosynthate stored in leaves as starch or sucrose. To examine the response of partitioning to natural daylight, soybeans (Glycine max [L.] Merr. cv Williams) were grown at 12 different times between May and November in a constant temperature greenhouse without supplemental lighting. Plants were transferred from the greenhouse to a controlled environment chamber at the end of civil twilight at a set developmental stage (expanding seventh trifoliolate leaf, counting acropetally). Net photosynthesis and the accumulation of starch and sugar in fully expanded fourth trifoliolate leaves were determined the following day under standard conditions in the chamber (lights-on synchronized with sunrise). Photosynthesis on a leaf area basis decreased about 10% between midsummer and early autumn. Leaf soluble sugar accumulation was low at all harvests. However, a twofold increase in photosynthate partitioning into starch occurred over the same time period, resulting in an 80% increase in absolute starch accumulation rate. Starch was responsible for about 78% of the increase in leaf dry matter during the light at all harvests, indicating that starch accumulation as affected by prior daylight conditions will alter export of photosynthate during the light period. Photosynthate partitioning into starch was linearly correlated with daylength at harvest, prior average peak solar irradiance, and other parameters that correlated with daylength and solar radiation such as harvested top dry matter. The relation between growth and seasonal changes in daylight (including daylength, irradiance, and light integral) are discussed in relation to photosynthate partitioning under field conditions.
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Selected References
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- Britz S. J., Hungerford W. E., Lee D. R. Photoperiodic Regulation of Photosynthate Partitioning in Leaves of Digitaria decumbens Stent. Plant Physiol. 1985 Aug;78(4):710–714. doi: 10.1104/pp.78.4.710. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carlson D. R., Brun W. A. Effect of shortened photosynthetic period on C-assimilate translocation and partitioning in reproductive soyeans. Plant Physiol. 1984 Aug;75(4):881–886. doi: 10.1104/pp.75.4.881. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Chatterton N. J., Silvius J. E. Photosynthate Partitioning into Starch in Soybean Leaves: I. Effects of Photoperiod versus Photosynthetic Period Duration. Plant Physiol. 1979 Nov;64(5):749–753. doi: 10.1104/pp.64.5.749. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chatterton N. J., Silvius J. E. Photosynthate Partitioning into Starch in Soybean Leaves: II. IRRADIANCE LEVEL AND DAILY PHOTOSYNTHETIC PERIOD DURATION EFFECTS. Plant Physiol. 1981 Feb;67(2):257–260. doi: 10.1104/pp.67.2.257. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mirecki R. M., Teramura A. H. Effects of Ultraviolet-B Irradiance on Soybean : V. The Dependence of Plant Sensitivity on the Photosynthetic Photon Flux Density during and after Leaf Expansion. Plant Physiol. 1984 Mar;74(3):475–480. doi: 10.1104/pp.74.3.475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raghuprasad P. K., Brooks S. M., Litwin A., Edwards J. J., Bernstein I. L., Gallagher J. Quillaja bark (soapbark)--induced asthma. J Allergy Clin Immunol. 1980 Apr;65(4):285–287. doi: 10.1016/0091-6749(80)90157-8. [DOI] [PubMed] [Google Scholar]
- Silvius J. E., Chatterton N. J., Kremer D. F. Photosynthate partitioning in soybean leaves at two irradiance levels: comparative responses of acclimated and unacclimated leaves. Plant Physiol. 1979 Nov;64(5):872–875. doi: 10.1104/pp.64.5.872. [DOI] [PMC free article] [PubMed] [Google Scholar]