Uniformly 15N‐labeled soybean seeds produced for use in human and animal nutrition studies: Description of a recirculating hydroponic growth system and whole plant nutrient and environmental requirements

A recirculating hydroponic technique which enables the uniform 15N-labeling of soybean plants has been developed. Daily net influx of nitrate, potassium, calcium, chloride and phosphate, as well as total solution uptake, was measured for a crop of 60 plants grown in a 3 m2 area. A protocol is presented which (i) maintains adequate nutrient concentrations for the crop, (ii) adds nutrients and water as required with no exchange of solution, and (iii) minimizes the addition and use of 15N. With this technique, 6.5 mol of 15N were used to generate 1 kg (DW) of soybean seeds (350 g protein kg-1; 98 atm% 15N) and 3.1 kg (DW) total biomass; recovery of nitrogen in the total biomass was 95%. 15N-labeled soy protein isolate or harvested plant parts (eg leaves or stems) can be used to investigate nutrient absorption and metabolism in human or animal studies.

[1]  R. E. Carlson,et al.  Soybean Seed Quality Response to Drought Stress and Pod Position , 1992 .

[2]  P. Klein,et al.  Uniformly 13C-labeled algal protein used to determine amino acid essentiality in vivo. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[3]  B. A. Mcblain,et al.  Registration of 'Gnome 85' soybean , 1991 .

[4]  D. Edwards,et al.  Decreased Rates of Nitrate Uptake During Pod Fill by Cowpea, Green Gram, and Soybean , 1988 .

[5]  R. Chaney,et al.  Complexity of iron nutrition: Lessons for plant‐soil interaction research , 1987 .

[6]  J. Imsande.  Nitrate-Ammonium Ratio Required for pH Homeostasis in Hydroponically Grown Soybean , 1986 .

[7]  A. H. Gibson,et al.  Nitrate Effect on Nodulation of Soybean by Bradyrhizobium japonicum1 , 1985 .

[8]  Judith F. Thomas,et al.  Photoperiod and Temperature Regulation of Floral Initiation and Anthesis in Soya Bean , 1983 .

[9]  E. Ralston,et al.  Hydroponic growth and the nondestructive assay for dinitrogen fixation. , 1981, Plant physiology.

[10]  D. Hume,et al.  Flowering, Abortion, and Yield of Early-Maturing Soybeans at Three Densities1 , 1978 .

[11]  D. Rains,et al.  Simultaneous measurement of nitrogen fixation estimated by acetylene-ethylene assay and nitrate absorption by soybeans. , 1978, Plant physiology.

[12]  M. B. Parker,et al.  Mn Concentration in Soybean Leaf Related to Bean Yields1 , 1977 .

[13]  D. Heenan,et al.  Tolerance of Soybean Cultivars to Manganese Toxicity1 , 1976 .

[14]  W. Fehr,et al.  Stage of Development Descriptions for Soybeans, Glycine Max (L.) Merrill , 1971 .

[15]  J. E. Harper,et al.  Seasonal Nutrient Uptake and Accumulation Patterns in Soybeans1 , 1971 .

[16]  R. Whitehead,et al.  Application of stable isotope tracers in studies of human metabolism. , 1990 .

[17]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[18]  R. Weiland,et al.  Gaseous Nitrogen Loss from Soybean Foliage1 , 1979 .

[19]  H. Mckenzie,et al.  The Kjeldahl determination of nitrogen : a critical study of digestion conditions-temperature, catalyst, and oxidizing agent. , 1954 .