Abstract
Radioactive photosynthetic assimilates, translocated to a soybean (Glycine max [L.] Merr. `Fiskeby V') pod can be measured directly by excising the stylar tip of the pod under 20 mm ethylenediaminetetraacetate solution (pH 7.0) and allowing the material to leak into the solution. Pods at the source node received approximately 50% of the 14C exported from the source leaf to the pod and leaked approximately 1 to 3% of this into the solution. More than 90% of the 14C that leaked from the pods was found in the neutral fraction and, of this, about 93% was in sucrose. Fifteen amino acids were identified in the leakage including: alanine, arginine, asparagine, γ-aminobutyric acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, phenylalanine, serine, threonine, tyrosine, and valine. The majority of the 14C in the basic fraction was found in serine (≃30%) and asparagine (≃23%). The inorganic ions K, Ca, P, Mg, Zn, and Fe were found in the leakage component. Nitrate was not detectable in the collected leakage solution. The absence of NO3− and the large proportion of the label in sucrose suggest a possible phloem origin for most of the material. The technique provides an uncomplicated, reproducible means of analyzing the material translocated into and through the soybean pod, as well as following the time course of label arrival at the pod.
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- Clauss H., Mortimer D. C., Gorham P. R. Time-course Study of Translocation of Products of Photosynthesis in Soybean Plants. Plant Physiol. 1964 Mar;39(2):269–273. doi: 10.1104/pp.39.2.269. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fisher D. B. Kinetics of C-14 Translocation in Soybean: II. Kinetics in the Leaf. Plant Physiol. 1970 Feb;45(2):114–118. doi: 10.1104/pp.45.2.114. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fisher D. B. Kinetics of C-14 translocation in soybean: I. Kinetics in the stem. Plant Physiol. 1970 Feb;45(2):107–113. doi: 10.1104/pp.45.2.107. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Flinn A. M., Atkins C. A., Pate J. S. Significance of photosynthetic and respiratory exchanges in the carbon economy of the developing pea fruit. Plant Physiol. 1977 Sep;60(3):412–418. doi: 10.1104/pp.60.3.412. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fondy B. R., Geiger D. R. Sugar Selectivity and Other Characteristics of Phloem Loading in Beta vulgaris L. Plant Physiol. 1977 May;59(5):953–960. doi: 10.1104/pp.59.5.953. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heathcote J. G., Haworth C. An improved technique for the analysis of amino acids and related compounds on thin layers of cellulose. II. The quantitative determination of amino acids in protein hydrolysates. J Chromatogr. 1969 Aug 5;43(1):84–92. doi: 10.1016/s0021-9673(00)99169-6. [DOI] [PubMed] [Google Scholar]
- Housley T. L., Fisher D. B. Estimation of Osmotic Gradients in Soybean Sieve Tubes by Quantitative Autoradiography: Qualified Support for the MUnch Hypothesis. Plant Physiol. 1977 Apr;59(4):701–706. doi: 10.1104/pp.59.4.701. [DOI] [PMC free article] [PubMed] [Google Scholar]
- King R. W., Zeevaart J. A. Enhancement of Phloem exudation from cut petioles by chelating agents. Plant Physiol. 1974 Jan;53(1):96–103. doi: 10.1104/pp.53.1.96. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pate J. S., Sharkey P. J., Atkins C. A. Nutrition of a developing legume fruit: functional economy in terms of carbon, nitrogen, water. Plant Physiol. 1977 Mar;59(3):506–510. doi: 10.1104/pp.59.3.506. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Quebedeaux B., Chollet R. Growth and Development of Soybean (Glycine max [L.] Merr.) Pods: CO(2) Exchange and Enzyme Studies. Plant Physiol. 1975 Apr;55(4):745–748. doi: 10.1104/pp.55.4.745. [DOI] [PMC free article] [PubMed] [Google Scholar]