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 Web of Science 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 Web of Science (45) Citing Articles via Google Scholar Google Scholar Articles by Kerr, P. S. Articles by Israel, D. W. Search for Related Content PubMed PubMed Citation Articles by Kerr, P. S. Articles by Israel, D. W. Agricola Articles by Kerr, P. S. Articles by Israel, D. W.

Articles

Effect of N-Source on Soybean Leaf Sucrose Phosphate Synthase, Starch Formation, and Whole Plant Growth ¹

United States Department of Agriculture, Agricultural Research Service, North Carolina State University, Raleigh, North Carolina 27695-7631, Department of Crop Science, North Carolina State University, Raleigh, North Carolina 27695-7631, Department of Soil Science, North Carolina State University, Raleigh, North Carolina 27695-7631, Department of Botany, North Carolina State University, Raleigh, North Carolina 27695-7631

Soybeans (Glycine max L. Merr. cv Tracy and Ransom) were grown under N₂-dependent or NO₃^–-supplied conditions, and the partitioning of photosynthate and dry matter was characterized. Although no treatment effects on photosynthetic rates were observed, NO₃^–-supplied plants in both cultivars had lower starch accumulation rates than N₂-dependent plants. Leaf extracts of NO₃^–-supplied plants had higher activities of sucrose phosphate synthase (SPS) and cytoplasmic fructose-1,6-bisphosphatase (FBPase) than N₂-dependent plants. The variation in starch accumulation was correlated negatively with the activity of SPS, but not the activity of FBPase, UDP-glucose pyrophosphorylase, or ADP-glucose pyrophosphorylase. These results suggested that starch accumulation is biochemically controlled, in part, by the activity of SPS. Leaf starch content at the beginning of the photoperiod was lower in NO₃^–-supplied plants than N₂-dependent plants in both cultivars which suggested that net starch utilization as well as accumulation was affected by N source.

Total dry matter accumulation and dry matter distribution was affected by N source in both cultivars, but the cultivars differed in how dry matter was partitioned between the shoot and root as well as within the shoot. The activity of SPS was correlated positively with total dry matter accumulation which suggested that SPS activity is related to plant growth rate. The results suggested that photosynthate partitioning is an important but not an exclusive factor which determines whole plant dry matter distribution.

This article has been cited by other articles:

				T. Ishimaru, T. Hirose, T. Matsuda, A. Goto, K. Takahashi, H. Sasaki, T. Terao, R.-i. Ishii, R. Ohsugi, and T. Yamagishi Expression Patterns of Genes Encoding Carbohydrate-metabolizing Enzymes and their Relationship to Grain Filling in Rice (Oryza sativa L.): Comparison of Caryopses Located at Different Positions in a Panicle Plant Cell Physiol., April 1, 2005; 46(4): 620 - 628. [Abstract] [Full Text] [PDF]

				R. Datta, K. C. Chamusco, and P. S. Chourey Starch Biosynthesis during Pollen Maturation Is Associated with Altered Patterns of Gene Expression in Maize Plant Physiology, December 1, 2002; 130(4): 1645 - 1656. [Abstract] [Full Text] [PDF]