ON THE CLAIMED ‘ADAPTIVE’ NATURE OF IAA-OXIDASE AND AN EFFECT OF GREEN LIGHT ON IAA-OXIDASE ACTIVITY

1965 ◽  
Vol 43 (8) ◽  
pp. 885-892 ◽  
Author(s):  
William G. Boll
Keyword(s):  
Oxidase Activity ◽  
Green Light ◽  
Lag Phase ◽  
Iaa Oxidase ◽  
Photo Effect ◽  
Published Evidence ◽  
Adaptive Nature ◽  
Light Maximum ◽  
Maximum Transmission

This paper examines the claim by Galston and Dalberg (Am. J. Botany, 41, 373 (1954), that IAA-oxidase is an adaptive enzyme, by which was meant that it is an enzyme formed as a consequence of the presence of IAA. Certain of the published evidence is rejected as irrelevant to the question.It is shown here that crude IAA-oxidase preparations from etiolated pea buds show a lag phase in IAA destruction whereas this is not so with enzyme from hook tissue or older stem tissue.Pretreatment of hook tissue or older tissue with IAA did not increase IAA-oxidase activity. It is confirmed that IAA-oxidase preparations from buds pretreated with IAA gave more destruction of IAA, when measured after 60 minutes, than did enzyme from untreated buds. This difference occurred because of elimination of the lag phase in destruction and not because of induced formation of enzyme.The lag phase in IAA-oxidase activity with enzyme extracted from buds was increased by exposing the seedlings to 3 minutes of weak green light (maximum transmission 520 mμ) at 16 hours before harvest. Pretreatment of such light-treated buds with IAA did not completely eliminate the lag phase in IAA-oxidase activity. It is suggested that these effects of green light are a new photo-effect in plants.

scholarly journals No effect of plant growth retarding compounds and growth stimulators on indolo-3-acetic acid oxidase activity in greening cucumber cotyledons

2015 ◽  
Vol 42 (3) ◽  
pp. 441-452 ◽  
Author(s):  
J. S. Knypl
Keyword(s):  
Oxidase Activity ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Acid Oxidase ◽  
Iaa Oxidase ◽  
Crude Enzyme Extract ◽  
Chlorophyll Accumulation ◽  
Cucumber Cotyledons ◽  
Amo 1618 ◽  
Molecular Sieving

Cotyledons dissected from 5-day-old etiolated cucumber seedlings were incubated in solutions on AMO-1618, B-Nine, CCC and Phosfon D for 48 h in light. In some tests the retardants were applied in mixed solutions with GA<sub>3</sub> or BAP. IAA oxidase was extracted and purified by means of molecular sieving through a bed of Sephadex G-25. The retardants inhibited chlorophyll synthesis by 50 % or more, and had essentially no effect on IAA oxidase activity per cotyledon basis. GA<sub>3</sub> and BAP also had no effect on enzyme activity in spite of a fact that the compounds stimulated growth of the cotyledons. The crude enzyme extract from B-Nine treated cotyledons showed lower IAA oxidase activity in comparison with the water treated control, the effect being due to a longer lag-phase preceding the initiation of IAA oxidation. KNO<sub>3</sub> strikingly stimulated expansional growth of the cotyledons, the effect being correlated with the accelerated chlorophyll accumulation. KNO<sub>3</sub> had no effect on IAA oxidase activity per cotyledon and decreased it per gram fr wt. It is concluded that [1] the growth rate of cucumber cotyledons is not correlated with IAA oxidase activity, and ;[2] the growth retarding compounds do not affect IAA oxidase system is this tissue.

The heme moiety in peanut peroxidase

1984 ◽  
Vol 62 (11) ◽  
pp. 1046-1050 ◽  
Author(s):  
R. N. Chibbar ◽  
R. Cella ◽  
R. B. Van Huystee
Keyword(s):  
Peroxidase Activity ◽  
Active Site ◽  
Oxidase Activity ◽  
Indoleacetic Acid ◽  
Iaa Oxidase ◽  
Equimolar Ratio ◽  
Immunological Properties ◽  
Peanut Peroxidase

Heme is present in an equimolar ratio to the apoprotein in the major cationic fraction of peanut peroxidase. The removal of heme from the holoenzyme does not affect the physicochemical and immunological properties of the apoperoxidase, however peroxidase activity is completely lost. The indoleacetic acid (IAA) oxidase activity of the apoperoxidase is reduced to 1/20 of the original holoenzyme. Both the peroxidase and IAA-oxidase activity could partially be restored in the holoenzyme reconstituted with hemin. It is suggested that heme may also participate in the IAA-oxidase activity possibly by altering the active site.

Isolation and Characterization of Flavonol Converting Enzymes from Mentha piperita Plants and from Mentha arvensis Cell Suspension Cultures

1979 ◽  
Vol 34 (3-4) ◽  
pp. 200-209 ◽  
Author(s):  
Gudrun Frey-Schröder ◽  
Wolfgang Barz
Keyword(s):  
Cell Suspension ◽  
Oxidase Activity ◽  
Enzyme Reaction ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
Mentha Piperita ◽  
Mentha Arvensis ◽  
Iaa Oxidase ◽  
Isolation And Characterization ◽  
Group I

Abstract Peroxidases from several plants, including horseradish peroxidase, were capable of converting flavonols to the corresponding 2,3-dihydroxyflavanones in presence of H2O2 . Contrastingly, protein extracts from Mentha piperita plants and Mentha arvensis cell suspension cultures perform ed the same enzymatic step in absence of H2O2 , but only with quercetin, not with kaempferol. H2O2-independent, quercetin converting enzymes were isolated and purified from these extracts, and they could be classified in two groups according to the extent of stimulation of the enzyme reaction by H2O2 . Enzymes from group I were stimulated by exogenous H2O2 , and they resembled horse­ radish peroxidase in several aspects. They possessed IAA oxidase activity, but quercetin was the preferred substrate. Enzymes from group II from the plants appeared to be a distinctly different set of enzymes. They were not stimulated by H2O2 , but required molecular oxygen and converted only 3,3′,4′-trihydroxyflavones under aerobic conditions. Also, they showed no Soret-bands and possessed no IAA oxidase activity. These proteins appear to be a new class of enzymes participating in the first step of flavonol degradation in plants.

scholarly journals Physiological and biochemical effects of morphactin IT 3233 on callus and tumour tissues of Nicotiana tabacum L. cultured in vitro. IV. IAA oxidase activity. Oat coleoptile biotest

2015 ◽  
Vol 43 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Z. Chirek
Keyword(s):  
Oxidase Activity ◽  
Callus Tissue ◽  
Tissue Growth ◽  
Tumour Tissue ◽  
Iaa Oxidase ◽  
Nicotiana Tabacum L ◽  
Coleoptile Elongation ◽  
Short Time ◽  
Physiological And Biochemical

IAA oxidase activity in callus and tumour tissue of tobacco subjected to the action of morphactin IT 3233 for shorter and longer periods was determined. Control tumour tissue shows an activity higher by about 40 per cent as compared with that of callus tissue. Morphactin applied for a short time (24-h incubation) does not change the activity of the enzyme. When application is prolonged, a considerable enhancement (up to 140%) of the enzyme activity in callus tissue is observed in dependence on the morphactin concentration. In tumour tissues the activity is stimulated by 45 per cent as compared to control. Oat coleoptile elongation growth induced by IAA is limited to 40 per cent when morphactin is added in the concentrations used for tobacco tissue cultures. The possibility of the morphactin action on tissue growth via IAA metabolism is discussed.

Changes in IAA oxidase activity in rooting hypocotyl cuttings ofPhaseolus mungo L.

1979 ◽  
Vol 35 (2) ◽  
pp. 202-203 ◽  
Author(s):  
R. N. Chibbar ◽  
K. Gurumurti ◽  
K. K. Nanda
Keyword(s):  
Oxidase Activity ◽  
Iaa Oxidase ◽  
Hypocotyl Cuttings

Inhibition of IAA oxidase activity of wheat anionic peroxidase by chitooligosaccharides

2016 ◽  
Vol 52 (5) ◽  
pp. 547-552 ◽  
Author(s):  
I. V. Maksimov ◽  
Z. R. Yusupova ◽  
E. A. Cherepanova ◽  
R. M. Khairulin ◽  
V. A. Vakhitov
Keyword(s):  
Oxidase Activity ◽  
Iaa Oxidase ◽  
Anionic Peroxidase
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