Biosynthesis of Porphyrins in Wheat Leaves: Ii. 5-Aminolaevulinate Hydro-Lyase

Nandi, Dhirendra L.; Waygood, E. R.

doi:10.1139/o67-036

Cited by 53 publications

(24 citation statements)

References 12 publications

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“…The optimum pH value of 8.2 for ALAD in the nongreen tissue is the same as reported by Schneider (23,24) for ALAD from tobacco pith tissue and spinach leaves. The optimum pH value of 9.5 observed for the ALAD from green tissue, or from nongreen tissue 3 or 4 weeks after the induction of greening, is different from those reported for other plant tissues or bacteria (4,(21)(22)(23)(24)28). However, the value observed in the present work is similar to that reported for ALAD from yeast by De Barreiro (5).…”

Section: Discussioncontrasting

confidence: 80%

Kinetin-induced Changes in δ-Aminolevulinic Acid Dehydratase of Tobacco Callus

Kaul

Sabharwal²

1974

Plant Physiol.

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Kinetin-induced changes in dry weight, soluble protein content, 6-aminolevulinic acid dehydratase activity, and chlorophyll content of two clones of Nicotiana tabacum L. callus were studied. Kinetin brought about a marked increase in the 5-aminolevulinic acid dehydratase activity of nongreen tissue just before induction of greening. The experimental data suggested a possible induction of specific chloroplast protein(s) during the kinetin-induced greening of nongreen tobacco tissue. Kinetin caused a decline in the 5-aminolevulinic acid dehydratase activity and chlorophyll content of the green callus used in the present study.Although there have been a number of investigations concerning the biochemical events during greening of higher plant tissues (1,3,7,(8)(9)(10)(11)(12)20), the accompanying changes in enzymes for Chl synthesis are not well studied. The little work done on the changes in Chl synthesis enzymes has been confined to light-induced greening (22-25, 28, 29, 31 Chlorophyll synthesis was studied on a medium containing salts and vitamins of modified (13) Murashige and Skoog's medium supplemented with 6% sucrose and 2 mg/l of kinetin. This medium has been referred to as CIM in this paper. Media were gelled with 0.8% agar. The pH was adjusted to 5.8 before the

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Section: Discussioncontrasting

confidence: 80%

Kinetin-induced Changes in δ-Aminolevulinic Acid Dehydratase of Tobacco Callus

Kaul

Sabharwal²

1974

Plant Physiol.

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“…ALA dehydratase (EC 4.3.1.24) was assayed by a modification of the method of Nandi and Waygood (20). Ten g of etiolated leaves, irradiated for I h, were ground in a mortar and pestle at 4 C in 20 ml of 50 mm Tris-HCl, pH 7.6, containing 10 mm cysteine.…”

Section: Methodsmentioning

confidence: 99%

The Effects of Levulinic Acid and 4,6-Dioxoheptanoic Acid on the Metabolism of Etiolated and Greening Barley Leaves

Meller

Gassman²

1981

Plant Physiol.

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Application of levulinic acid (LA), a competitive inhibitor of 8-aminolevulinic acid (ALA) dehydratase, to greening plant tissues causes ALA to accumulate at the expense of chlorophyll. 4,6-Dioxoheptanoic acid (DA), which has been reported to be an effective inhibitor of this enzyme in animal systems, has a similar but more powerful effect on Byron, Minn., were germinated in vermiculite in darkness at 22 C.All manipulations of plant material were carried out under a dim green safelight (7). The apical 5-cm portion of 7-day-old leaves was excised in the dark and divided into 1-cm segments. One g lots were placed into 125-ml Erlenmeyer flasks containing 1 to 5 ,uCi of "4C-labeled compound, plus any additions, in 1.0 ml of 50 mm K-phosphate buffer, pH 5.0, and incubated for up to 4 h in the dark or in the light. Incubations with 32Pi were carried out in 50 mm citrate buffer, pH 5.0.Irradiations. Irradiations were carried out at 22 C for the indicated time under GE Cool-White fluorescent lamps at an irradiance of 1.5 x 104 ergs/cm2. s.Assay of ALA Dehydratase. ALA dehydratase (EC 4.3.1.24) was assayed by a modification of the method of Nandi and Waygood (20). Ten g of etiolated leaves, irradiated for I h, were ground in a mortar and pestle at 4 C in 20 ml of 50 mm Tris-HCl, pH 7.6, containing 10 mm cysteine. After filtration through four layers of cheese cloth, the extract was centrifuged at 18,000g for 15 min, and the supernatant used as a source of enzyme. Incubations were carried out at 30 C, with or without LA or DA, as indicated. The reaction mixture contained: ALA, 7.5 .tmol; 98 ,umol; MgCl2, 9.9 ,umol; GSH, 30,umol; and protein, 1.25 mg, in a final volume of 3.0 ml. The reaction was stopped by addition of 1.0 ml of 20% trichloroacetic acid, and porphobilinogen was determined by the method of Mauzerall and Granick (17).Determination of ALA Accumulation in Vivo. ALA, which accumulated in irradiated barley leaves treated with LA or DA, was determined as described previously (12

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“…The increased concentrations of haem precursors in the urine and erythrocytes may therefore reflect the com pensatory increases in substrate concentrations that are necessary to maintain haem synthesis in the face of de creases in the activity of some enzymes in the pathway. Other divalent cations in excess include silver, copper, and cadmium which also inhibit 8-ALA dehydratase [61,62], Whereas the alkali metals such as lithium and rubid ium [63] and the divalent cations magnesium, calcium and manganese enhanced the activity of 8-ALA dehydra tase [64]; although by no means all have effects demon strable at physiological concentrations. Zinc and alumi nium both stimulate 8-ALA dehydratase activity and can overcome the inhibitory effects of lead in in vitro and in vivo studies [65].…”

Section: Metal Ion Interaction In Haem Biosynthesismentioning

confidence: 99%