Acid-Soluble Nucleotides of Pinto Bean Leaves at Different Stages of Development

Weinstein, Leonard H.; McCune, D.C.; Mancini, Jill F.; Leuken, P. Van

doi:10.1104/pp.44.11.1499

Cited by 21 publications

(8 citation statements)

References 27 publications

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“…These observations are supported by those of the accompanying study (23) (7) proposed that nitrite reduction utilizes the NADPH generated by the oxidation of glucose-6-P. (Table II) that are comparable in range to that found in young tissues of other plants (20). For all tissues examined in this study, ammonium nutrition yielded a higher concentration of total adenine nucleotide than that found with nitrate nutrition.…”

Section: Methods Of Analysissupporting

confidence: 80%

Influence of Ammonium and Nitrate Nutrition on the Pyridine and Adenine Nucleotides of Soybean and Sunflower

Weissman

1972

Plant Physiol.

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Total pyridine nucleotide concentration of root tissue for young soybean (Glycine max var. Bansei) and sunflower (Helianthus annuus L. var. Mammoth Russian) plants is the same with either ammonium or nitrate, but nitrate results in an increased proportion of total oxidized plus reduced NADP (NADP [H]) seemingly at the expense of NAD. The activity of NADH-and NADPH-dependent forms of glutamic acid dehydrogenase is correlated with the ratio of total oxidized plus reduced NAD to NADP(H). The low NAD:NADH ratio maintained in nitrate roots despite active NADH utilization via nitrate reductase and glutamic acid dehydrogenase may be the result of nitrate-stimulated glycolysis. Nitrate roots also maintain a high level of NADPH, presumably by the stimulatory effect of nitrate utilization on glucose-6-phosphate dehydrogenase activity. In the presence of nitrate rather than ammonium, the highly active nitrate-reducing leaves of soybean show a greater proportion of total pyridine nucleotide in the form of NADP(H) than do the inactive leaves of sunflower.For all tissues examined, ammonium nutrition yields a higher concentration of total adenine nucleotide than is found with nitrate. The data indicate the production of a higher level of metabolites that enter into purine synthesis with ammonium than with nitrate. Glutamine synthetase activity can be correlated with the concept that enzymes utilizing ATP for biosynthetic purposes increase in activity in accordance with the energy level of the cell.Studies of recent years have indicated that ammonium and nitrate nutrition may lead to differences in the chemical composition of plants (11,14,18). In an accompanying study (23), it has been shown that the form of inorganic nitrogen supplied to soybean and sunflower plants leads to differences in activity of nitrate and ammonium assimilating enzymes and to glucose-6-phosphate dehydrogenase. It is known that such enzymes as nitrate reductase, nitrite reductase, glutamic acid dehydrogenase, and glucose-6-phosphate dehydrogenase are dependent for their activity on either NAD or NADP (6). Furthermore, glutamine synthetase requires ATP for its activity (6). (24) that maintained the solution bathing the root system at a constant pH. As in the accompanying study (23), the roots and the oldest of the two trifoliate leaves of soybean that had developed by the 19th day were selected for harvest and analysis. For sunflower, roots and the second set of the three sets of leaves were utilized. Midribs were removed from leaves and leaflets and root systems were thoroughly washed with a vigorous stream of distilled water before tissues were subjected to analysis. METHODS OF ANALYSISPyridine Nucleotides. Following the method of Glock and McLean (9), oxidized and reduced pyridine nucleotides were extracted by a 2-min homogenization in a hot Waring Blendor of 3 g fresh tissue with 15 ml of heated (90 C) 0.1 N HCI and 0.1 N NaOH, respectively. The homogenates were made icecold and were brought to pH 7.6 with either 2 N NaOH or 2 N HCI and 0.3 ...

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Section: Methods Of Analysissupporting

confidence: 80%

Influence of Ammonium and Nitrate Nutrition on the Pyridine and Adenine Nucleotides of Soybean and Sunflower

Weissman

1972

Plant Physiol.

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“…The BA enhancement effect on the e/X ratio or on the "energy charge" changed from 5 % at week 3 to 27% at weeks 5 to 7. The relatively low percentage changes of these parameters during senescence, compared to those reported for other metabolites, may result from the active participation of kinases and regulatory mechanisms that maintain the energy status of the nucleotide system (26); and only a small change in the ATP system is required for metabolic regulation (6). The BA effect may therefore be interpreted as being due to the conferring of maximal flexibility in regulating rates of biosynthetic sequences, thus bringing about an orderly metabolic coordination between energy production and energy utilization for biosynthetic and growth processes.…”

Section: Resultsmentioning

confidence: 99%

Retardation of Bean Leaf Senescence by Benzyladenine and Its Influence on Phosphate Metabolism

Adedipe¹,

Fletcher²

1970

Plant Physiol.

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The levels of glucose, sugar phosphates, and adenosine phosphates were determined in primary leaves of intact bean plants during normal senescence and compared to leaves in which senescence was delayed by application of benzyladenine (BA). In both cases there was a rise with time in the levels of glucose 1-phosphate, glucose 6-phosphate, and fructose 6-phosphate, and a decline in 2-phosphoglyceric acid, inorganic phosphate, and the adenosine phosphates (AMP, ADP, ATP). The levels of fructose 1,6-diphosphate remained fairly constant. Although the levels of hexose phosphates, adenosine phosphates, and inorganic phosphate were lower in the BA-treated leaves, the incorporation of 32P into these compounds by 3-and 6-week-old plants was higher than in the controls. These results suggest that the retardation of leaf senescence by BA in intact bean plants is associated with increased utilization of metabolites, indicating a more rapid turnover of the adenosine phosphates. It is concluded that this effect is brought about by a regulatory coordination of metabolic processes in relation to energy production and utilization.During leaf senescence there is a decline in the levels of chlorophyll, protein, and RNA (10, 12), associated with the loss of mitochondrial function and phosphorylative activity (13,25). In 1957 Richmond and Lang (21) reported that kinetin retarded senescence of detached Xanthium leaves. It has since been demonstrated that various growth substances, particularly the cytokinins, are capable of delaying senescence of detached leaves (16) and intact plants (10).It has been suggested that increased longevity due to N6-benzyladenine treatment may be a consequence of enhanced nucleic acid and protein metabolism (10, 12) and a decrease in respiration (9) via the inhibition of respiratory kinases (24). However, the retardation of lettuce leaf senescence by BA8 was not always associated with a reduction in respiration (14). MacLean and Dedolph (19) using 2,4-dinitrophenol for studies of respiration in broccoli concluded that retardation of leaf senescence was due to conservation of ATP rather than inhibition of respiration per se.I This study was supported by grants from the National Research Council of Canada. Extraction of Metabolites. Starting from the 3rd week at weekly intervals, each leaf was excised from the petiole and weighed. A set of leaves from another plant was dried in a forced air oven at 65 C for 24 hr, and the percentage of dry matter was determined. The fresh leaves were extracted in methanolchloroform-formic acid-water (12:5:1:2, v/v) (MCF) by a procedure similar to that described by Bieleski and Young (7). The leaves were homogenized in 25 ml of MCF for 10 min, and the Blendor was rinsed twice with 25 ml of MCF. The homogenate was centrifuged (8000g) for 15 min at 0C. The supernatant was decanted, the residue was re-extracted twice, and the supernatant fractions were pooled and concentrated in vacuo at 40 C. Chlorophyll and phospholipids were removed with hexane, and the extracts wer...

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“…Adenine, guanine, uracil, and their respective nucleosides were detectable in mature wheat grains (GRZELCZAK and BUCHOWICZ 1975) related to the RNA synthesis. UDP-glucose, ADP-glucose, and GDP-glucose are detectable in young leaves of Phaseolus vulgaris (WEINSTEIN et al 1969). They are related to the sucrose, starch, and cellulose syntheses respectively.…”

Section: Occurrence Of Pyrimidines and Purines In Plantsmentioning

confidence: 99%

“…Figure 2 shows acid-soluble nucleotides fractionated from bean leaves ( Fig. 2A) (WEINSTEIN et al 1969) and Euglena gracilis ( Fig. 2B) (KRAUSS and REINBOTHE 1977).…”

Section: Occurrence Of Pyrimidines and Purines In Plantsmentioning

confidence: 99%

Metabolism of Pyrimidines and Purines

Wasternack¹

1982

Nucleic Acids and Proteins in Plants II

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Acid-Soluble Nucleotides of Pinto Bean Leaves at Different Stages of Development

Cited by 21 publications

References 27 publications

Influence of Ammonium and Nitrate Nutrition on the Pyridine and Adenine Nucleotides of Soybean and Sunflower

Influence of Ammonium and Nitrate Nutrition on the Pyridine and Adenine Nucleotides of Soybean and Sunflower

Retardation of Bean Leaf Senescence by Benzyladenine and Its Influence on Phosphate Metabolism

Metabolism of Pyrimidines and Purines

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