Amino acid composition in xylem sap of soybean related to the evaluation of N<sub>2</sub>fixation by the relative ureide method

Ohtake, Norikuni; Nishiwaki, Toshikazu; Mizukoshi, Kazushi; Minagawa, Ritsuko; Chinushi, Toshiaki; Ohyama, Takuji

doi:10.1080/00380768.1995.10419562

Cited by 22 publications

(22 citation statements)

References 10 publications

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“…In this study, we observed that the concentration of free amino acids was higher during daytime than at night and asparagine was the dominant amino acid found in the xylem sap. Our finding is consistent with an earlier report that showed an increase in the proportion of asparagine in xylem sap from 40 to 70% during seed development (Ohtake et al 1995). The relative abundance of asparagine in the xylem sap of soybean highlights the importance of this amino acid as a major nitrogen transport amino acid.…”

Section: Discussionsupporting

confidence: 94%

Protein and metabolite composition of xylem sap from field-grown soybeans (Glycine max)

Krishnan

Natarajan²,

Bennett

et al. 2011

Planta

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The xylem, in addition to transporting water, nutrients and metabolites, is also involved in long-distance signaling in response to pathogens, symbionts and environmental stresses. Xylem sap has been shown to contain a number of proteins including metabolic enzymes, stress-related proteins, signal transduction proteins and putative transcription factors. Previous studies on xylem sap have mostly utilized plants grown in controlled environmental chambers. However, plants in the field are subjected to high light and to environmental stress that is not normally found in growth chambers. In this study, we have examined the protein and metabolite composition of xylem sap from field-grown cultivated soybean plants. One-dimensional gel electrophoresis of xylem sap from determinate, indeterminate, nodulating and non-nodulating soybean cultivars revealed similar protein profiles consisting of about 8-10 prominent polypeptides. Two-dimensional gel electrophoresis of soybean xylem sap resulted in the visualization of about 60 distinct protein spots. A total of 38 protein spots were identified using MALDI-TOF MS and LC-MS/MS. The most abundant proteins present in the xylem sap were identified as 31 and 28 kDa vegetative storage proteins. In addition, several proteins that are conserved among different plant species were also identified. Diurnal changes in the metabolite profile of xylem sap collected during a 24-h cycle revealed that asparagine and aspartate were the two predominant amino acids irrespective of the time collected. Pinitol (D-3-O-methyl-chiro-inositol) was the most abundant carbohydrate present. The possible roles of xylem sap proteins and metabolites as nutrient reserves for sink tissue and as an indicator of biotic stress are also discussed.

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Section: Discussionsupporting

confidence: 94%

Protein and metabolite composition of xylem sap from field-grown soybeans (Glycine max)

Krishnan

Natarajan²,

Bennett

et al. 2011

Planta

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“…Amino acid concentration in xylem sap represented totally different tendency, which indicated 3 to 6 times high level at nitrogen deficiency, as compared with leaves and roots, and huge difference in amino acid concentration among treatments was derived from the concentration of glutamine and asparagines. Our finding is consistent with earlier reports that showed an increase in the proportion of glutamine and asparagines in the xylem sap (Krishnan et al, 2011;Ohtake et al, 1995). It has been reported that changes in the nitrogen metabolism can affect the relative composition and concentration of amino acids in the xylem sap.…”

Section: Discussionsupporting

confidence: 83%

Temporal Changes in N Assimilation and Metabolite Composition of Nitrate-Affected Tomato Plants

Sung¹,

Lee²,

Lee³

et al. 2012

Korean Journal of Soil Science and Fertilizer

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The role of inorganic nitrogen assimilation in the production of amino acids, organic acids and soluble sugars is one of the most important biochemical processes in plants, and, in order to achieve normally, nitrate uptake and assimilation is essential. For this reason, the characterization of nitrate assimilation and metabolite composition from leaves, roots and xylem sap of tomato (Solanum lycopersicum) was investigated under different nitrate levels in media. Tomato plants were grown hydroponically in liquid culture under five different nitrate regimes: deficient (0.25 and 0.75 mM NO 3 -), normal (2.5 mM NO 3 -) and excessive (5.0 and 10.0 mM NO 3 -). All samples, leaves, roots and xylem sap, were collected after 7 and 14 days after treatment. The levels of amino acids, soluble sugars and organic acids were significantly decreased by N-deficiency whereas, interestingly, they remained higher in xylem sap as compared with N-normal and -surplus. The N-excessive condition did not exert any significant changes in metabolites composition, and thus their levels were similar with N-normal. The gene expression and enzyme activity of nitrate reductase (NR), nitrite reductase (NIR) and glutamine synthetase (GS) were greatly influenced by nitrate. The data presented here suggest that metabolites, as a signal messenger, existed in xylem sap seem to play a crucial role to acquire nitrate, and, in addition, an increase in α-ketoglutarate pathway-derived amino acids under N-deficiency may help to better understand plant C/N metabolism.

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“…Some part of NO 3 -is directly transported through xylem to the shoots and reduced in leaves. Ohtake et al (1995) reported the seasonal changes in amino acid composition in xylem sap of soybean and they confirmed that asparagine was the principal amino acids in xylem sap collected from basal cut end of the stem at any stages.…”

Section: Nodule Structure and Function Of Soybeanmentioning

confidence: 58%

Effect of Nitrate on Nodulation and Nitrogen Fixation of Soybean

Ohyama¹,

Fujikake²,

Yashima³

et al. 2011

Soybean Physiology and Biochemistry

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Amino acid composition in xylem sap of soybean related to the evaluation of N₂fixation by the relative ureide method

Cited by 22 publications

References 10 publications

Protein and metabolite composition of xylem sap from field-grown soybeans (Glycine max)

Protein and metabolite composition of xylem sap from field-grown soybeans (Glycine max)

Temporal Changes in N Assimilation and Metabolite Composition of Nitrate-Affected Tomato Plants

Effect of Nitrate on Nodulation and Nitrogen Fixation of Soybean

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Amino acid composition in xylem sap of soybean related to the evaluation of N2fixation by the relative ureide method

Cited by 22 publications

References 10 publications

Protein and metabolite composition of xylem sap from field-grown soybeans (Glycine max)

Protein and metabolite composition of xylem sap from field-grown soybeans (Glycine max)

Temporal Changes in N Assimilation and Metabolite Composition of Nitrate-Affected Tomato Plants

Effect of Nitrate on Nodulation and Nitrogen Fixation of Soybean

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Amino acid composition in xylem sap of soybean related to the evaluation of N₂fixation by the relative ureide method