Biosynthesis of ethylene. Enzymes involved in its formation from methional

Mapson, L. W.; Wardale, D. A.

doi:10.1042/bj1070433

Cited by 45 publications

(17 citation statements)

References 6 publications

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Section: Introductionmentioning

confidence: 67%

“…If this ethylene-synthesizing system functions in vivo, the growth regulatory activities of the peroxidative IAA-oxidase system may encompass those areas in which ethylene is involved as well as the growth phenomena associated with IAA. This additional regulatory role for peroxidases is supported by their association with in vitro ethylene synthesis in several studies (22,23,25).The micronutrient manganese has been implicated as a cofactor in both the IAA-destroying system (15,20,21) and the ethylene-synthesizing system (1, 39). High levels of substrate manganese resulting in high levels of tissue manganese reportedly increase both the peroxidase activity and the IAAoxidase activity in cotton (31, 35).…”

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confidence: 77%

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The Relationship of the Peroxidative Indoleacetic Acid Oxidase System to in Vivo Ethylene Synthesis in Cotton

Fowler

Morgan

1972

Plant Physiol.

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Since peroxidase and manganese have been implicated in both auxin destruction and ethylene production, the effect of auxins and high tissue levels of manganese on the peroxidative indoleacetic acid oxidase system and the internal level of ethylene was determined in cotton (Gossypium hirsutum L.cv. Watson GL-7). The highest level of manganese tested produced manganese toxicity symptoms, including necrotic lesions, accompanied by an increase in internal ethylene levels at about 15 days after treatment initiation. Statistically significant increases in indoleacetic acid oxidase and peroxidase activity were first observed 2 days later and were paralleled by tissue manganese levels above 7.4 milligrams per gram dry weight and internal ethylene levels of 0.77 microliters per liter air. Eight hours after application of 2,4-dichlorophenoxyacetic acid or indoleacetic acid, the internal levels of ethylene were increased to above 6.6 microliters per liter air in cotton plants, and levels of this magnitude were maintained for a 72-hour period of observation. Modification of peroxidase and indoleacetic acid oxidase activity in auxintreated plants definitely occurred well after the elevation of internal ethylene levels. While ethylene levels and indoleacetic acid oxidase activity were increased by both experimental approaches, the earlier appearance of increased ethylene indicates that the peroxidative indoleacetic acid oxidase system in cotton is not involved in ethylene synthesis or that this enzyme is not the rate-limiting factor when ethylene synthesis is increased. Ethylene, as well as auxin destruction, may be involved in some of the long term plant responses to toxic levels of manganese. The findings also suggest that auxin-induced ethylene may play a role in the elevation of peroxidase and indoleacetic acid oxidase activity eventually seen in extracts of plants treated with auxins. The data support the assumption that the enzymatic portion of the indoleacetic acid oxidase system in cotton is a peroxidase. Thimann's observation, sufficient evidence has been accumulated to define the major substance responsible for auxin activity as indole-3-acetic acid and to attribute the destruction of IAA within the plant, primarily, to a peroxidase-based enzyme system generally known as IAA-oxidase (11,15,20,28,34,37). By virtue of its role in limiting the supply of IAA within the plant, the IAA-oxidase system has been recognized as a plant growth regulatory mechanism.The potential role of the IAA-oxidase system as a plant growth regulatory mechanism assumed new dimensions with Yang's (39) discovery that an enzyme system strikingly similar to the peroxidative IAA-oxidase system is capable of synthesizing the plant hormone ethylene. If this ethylene-synthesizing system functions in vivo, the growth regulatory activities of the peroxidative IAA-oxidase system may encompass those areas in which ethylene is involved as well as the growth phenomena associated with IAA. This additional regulatory role for peroxidases is supported...

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Section: Introductionmentioning

confidence: 67%

mentioning

confidence: 77%

The Relationship of the Peroxidative Indoleacetic Acid Oxidase System to in Vivo Ethylene Synthesis in Cotton

Fowler

Morgan

1972

Plant Physiol.

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“…The presence of methane sulfinic acid, p-coumaric acid, and glucose oxidase, in cauliflower floret tissue, was demonstrated by Mapson et al (8,9). It is, therefore, reasonable to assume that in addition to peroxidase, these cofactors can leak from the tissue into the surrounding buffer solution which already contains SMKB, and thereby provide all the ingredients of the ethylene-forming model system.…”

Section: Methodsmentioning

confidence: 99%

An Evaluation of 4-S-Methyl-2-Keto-Butyric Acid as an Intermediate in the Biosynthesis of Ethylene

Lieberman¹,

Kunishi²

1971

Plant Physiol.

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Stimulation of ethylene production by cauliflower (Brassica oleracea var. botrytis L.) tissue in buffer solution containing 4-S-methyl-2-keto-butyric acid is not due to activation of the natural in vivo system. Increased ethylene production derives from an extra-cellular ethylene-forming system, catalyzed by peroxidase and other factors, which leak from the cauliflower tissue and cause the degradation of 4-S-methyl-2-keto-butyric acid. This exogenous ethylene-forming system is similar to the ethylene-forming horseradish peroxidase system which utilizes methional or 4-S-methyl-2-keto-butyric acid as substrate. We conclude that 4-S-methyl-2-keto-butyric acid is probably not an intermediate in the biosynthetic pathway between methionine and ethylene.Methionine is now established as a precursor of ethylene in higher plants (2, 5). There is, however, no unequivocal information concerning the enzymes and intermediates involved in the pathway from methionine to ethylene. Peroxidase was suggested as an enzyme system which could be involved in ethylene biosynthesis (5). Yang (14) subsequently described a model system for ethylene production in which horseradish peroxidase, catalyzed the conversion of methional or the a-keto analogue of methionine (4-S-methyl-2-keto-butyric acid) to ethylene. This system required a combination of monophenol, sulfite and Mn2+ or hydrogen peroxide as cofactors.Mapson and colleagues, in a series of papers, demonstrated a peroxidase in cauliflower florets which catalyzed production of ethylene from methional in the presence of p-coumaric acid or its methyl ester, hydrogen peroxide, and methane sulfinic acid (7-10). They identified all these accessory factors and a hydrogen peroxide-forming system in cauliflower extracts. Takeo and Lieberman (13) MATERIALS AND METHODSTissue and Tissue Treatment. Cauliflower (Brassica oleracea var. botrytis L.) heads were purchased in the wholesale market and stored at 0 C to be used as needed. The heads were separated into florets 5 mm in diameter and 7 mm long. In most experiments 3 g of florets were placed in 3 ml of 0.1 M phosphate buffer solution, pH 6.5, with or without SMKB, in a 25-ml Erlenmeyer flask, which was stoppered with a serum cap and incubated 4 hr at 30 C. This was designated a "buffer solution system" in contrast to a "no solution system" which was incubated in absence of buffer solution after a 1-hr preincubation soaking in SMKB.In the experiments with apple (Malus sylvestris Mill. cv. Rome) tissue, 4 apple plugs (about 1 g), prepared as described (5), were incubated 4 hr at 30 C in 5 ml of 0.4 M sucrose-0.1 M bicarbonate buffer, pH 8.7, in 25-ml flasks stoppered with serum caps. In all the closed systems a vial containing 0.5 ml of 10% KOH was included in the flask to absorb CO2.Tomato (Lycopersicon esculentum Mill. cv. Homestead) pericarp tissue (4 g) from half-ripe fruit was cut into 0.5-cm squares, as previously described (6)

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“…Since changes in membrane permeability have been correlated with the developmenit of lhardiniess (9), it is fascinating to speculate if specific peroxidases could be associated in the l)rocess. Peroxidative action has been correlated wvith ethylene sy-nthesis (10) and IAA metabolismii (6,8). Whether or not these latter fuinctions are involved in cold hardiness is unknowin.…”

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confidence: 99%

Plant Leaf and Stem Proteins. II. Isozymes and Environmental Cabbage

1969

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Abstract. The activity of 10 enzymes separated by acrylamide disc gel electrophoresis of leaf and stem extracts from Dianthus grown under summer and winter conditions was studied.While banding was constant and highly reproducible under each environment, differences between the 3 cultivars and between the tissues were evident. No significant differences in the isozyme patterns of glutamate dehydrogenase, 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, and catalase were observed between the 2 environments. Loss

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Biosynthesis of ethylene. Enzymes involved in its formation from methional

Cited by 45 publications

References 6 publications

The Relationship of the Peroxidative Indoleacetic Acid Oxidase System to in Vivo Ethylene Synthesis in Cotton

The Relationship of the Peroxidative Indoleacetic Acid Oxidase System to in Vivo Ethylene Synthesis in Cotton

An Evaluation of 4-S-Methyl-2-Keto-Butyric Acid as an Intermediate in the Biosynthesis of Ethylene

Plant Leaf and Stem Proteins. II. Isozymes and Environmental Cabbage

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