Formation of auxin from tryptophan through action of polyphenols

Gordon, Solon A.; Paleg, L. G.

doi:10.1104/pp.36.6.838

Cited by 105 publications

(33 citation statements)

References 22 publications

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“…The occurrence of IAA in infinitesimal concentrations in most hi'gher plant tissuies, the relaitively small yields obtained from in vitro biosynthesis, and the lability of the compotund in liight, 02 atmosphere and strong acid soluitionis pose = , problems that have never been solved entirely 8 9 10 satisfactorily. Problems in identification and analysis of IAA continue to exist despite the development of many valuable proce(lures involving paper B (2,5,7,12,13,15,23,33,34), thin-layer (17,21,22) and partition column (15,24,25,26) chromatography; electrophoresis (15, 23); gas chromatography (26); s9pectrophotofltiorometry (26); colorimetry (2,5,7,12,13,15,23,24,26,33,34) and spectrophotometry (7).…”

Section: Discussionmentioning

confidence: 99%

Biosynthesis of Indoleacetic Acid from Tryptophan-¹⁴C in Cell-free Extracts of Pea Shoot Tips

Moore

Shaner

1967

Plant Physiol.

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Summary. A 2-step, 1-d:,mens-ional thn-layer chromatograph-c proceduire fnr isolating indoleacetic ac:d (IAA) was developed and util:zed in inve,t at:ons of the biosynthesis of JAA from tryl)to,)han-_4C in cell-fre'-extracts of ipea (Pi.sun sativitmn L.) shoot tips. Identfcat;on of a 14C-prodnict as IAA was bv (a) co-chromatograT)hv of atitheiiitc IAA and '4C-pro(duict on th.:n-layer chromatography, and (b) gas-liqu-;d and thin-laver chromategraphy of authentic and presumptive IAA methyl esters. Dalysis of enzyme extracts and addt;on of a-keto-li1tqr`c ac d anl pvr:doxal phosphate to reactioni m;xtl'res re,ulited in ap)prox:mately 2-to 3-f-ld increases in net y;elds of IAA over yields in non-d:alyzed react-on m:xtres wW:ch d:d not conta;n ad,d:tives esqent:al to a translaminace reaction of trvptophan. Add`t:on of thiam:ne pyro0hoonbh,,te to reacton m;xtl,req fiurther enhanced npt b;h,vnth-s-s of I'A. It is conclhlded that the format;on of indolepyrtiv:c ac;d and its silhbenlent decarboxvlat:on prohablv are seeventtal react:onis in the maior pathway of IAA bocvnfhsis from trvntonhan in cell-free extracts of Pisutnt short t:pS. ComDar;-on of max:mtlm n't-IAA biosynthes;s in extracts of shoot t:ps of etiolated anid leht-grown dwvarf and tall pea !dluui;nzs reveal-id. aln order, on a uin:t T)rofe:n N ba:, of: 1`lo-4-rown tall > Pght-zrown dwarf > etiolated tall _ etolated dwarf. It is conclrxded that the d:fferent rates of stpm elonzation among et;el"ted and l:ght-pr-wrn dwarf and tal!l pea seedl:ngs are correlated, in general, with differences in net TAA biosynthesis aild setisiitivity of the tissules to IAA.Ex'olan.utions for the (Ifferer(nces in stemi elomioatioIl betweeil dwarf and(l tall varne;es of a snecies e.g. Pisumin sativ'mi, and betweon et;olatod atnd tlc-ht-grown l)lants of the sam-var;ety have he-n sought repeatedly throu"gh inve-t;zat:ons of pols):bVe (orrelat;ve difference,s in endogen-onls aulx;n an1d ib,berell;n relationships. The maiori'ty of these investigations have been either: (a) studies of comparat:ve resp)onses of intact see(linzs or excised stem sectioins to exogenotus hormones: or (b) extraction and bWoassay of enidozeniouis hormones. Another kin(d of exoer:mmntal avnroach which is tusefult in attempts to elu1cidate comparative g,rowth hormone relationships is invest:gation of hormone bWosvntheses tsi;ng cell-free enzymne prepatrations. Tn 1958, Gor(lon (12) f:rqt 'describe-d an enzyme system from shoot ti'ps of Phascoluts autreus seedlings w,hich catalvzed the coniversion of trvntophan to indole-3-acetic ac&d (IAA). Wghtman ;ind Cohen (39) recently described in detail the intermediary steps in the enzymic conlversion of trvptophan to TA.A in cell-free preparation;s from 1 This investigation was supported in part by Grauit GBI-4613 from the National Science Founidation. mntg be-an (Ph1 rscolls (1a1 remis) seedlPl;ngs. So)me propert e-of an TAA-syntheq;z;ng syvtem isol-te-d from ani:ces of Avona. coleoptiles and otllel-W'ant mrn-er:akc were de-cr'be,l by Lant.can and Mui:r (17). WhIle cel...

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Section: Discussionmentioning

confidence: 99%

Biosynthesis of Indoleacetic Acid from Tryptophan-¹⁴C in Cell-free Extracts of Pea Shoot Tips

Moore

Shaner

1967

Plant Physiol.

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“…Since no reduction in yield of indolepyruvate was observed in the absence of oxygen, oxidative deamination (10) apparently was not contributing to the production of indolepyruvate. Gordon and Paleg (11) reported that indolepyruvate and IAA also could be formed through the action of polyphenols on tryptophan in mung bean. Direct investigation revealed that neither was this reaction operative in the enzyme extracts prepared from peas.…”

Section: Resultsmentioning

confidence: 99%

Properties of an Aminotransferase of Pea (Pisum sativum L.)

Matheron¹,

Moore²

1973

Plant Physiol.

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A transaminase (aminotransferase, EC 2.6.1) fraction was partially purfied from shoot tips of pea (Pisum sativum L. cv. Transaminases (aminotransferases, EC 2.6. 1), particularly those of plants, are quite incompletely described in regard to their amino acid and keto acid specificities. Some partially purified preparations are highly specific for particular amino acids (1, 2, 5, 30). Other preparations reportedly transaminate a variety of amino acids (7,8,12,15,25,29). Many workers have concentrated on transamination of aromatic amino acids. Two transaminase fractions have been isolated from rat brain, one of which showed highest activity toward tyrosine and phenylalanine and the other of which showed highest activity toward tryptophan and 5-hydroxytryptophan (4, 6, 26). Partially purified tryptophan transaminase from the bacterium Clostridium sporogenes catalyzed the transamination of tyrosine and phenylalanine, as well as tryptophan (23). A transaminase fraction from mung bean (Phaseolus aureus) also transaminated tryptophan, phenylalanine, and tyrosine, as well as several aliphatic amino acids (7,8).The purpose of these investigations was to purify partially and ascertain some properties of a transaminase fraction from pea shoots and to attempt to corroborate the evidence reported by Moore (20) and kept under a 16-hr photoperiod at 20 + 1 C with a light intensity of 900 to 1000 ft-c and an 8-hr dark period at 16 + 1 C. After 10 to 14 days, 50 to 70 g of shoot tips were removed immediately above the fifth node and placed in liquid nitrogen for overnight storage prior to use.Preparation of Enzyme Extract. Each sample of shoot tips was homogenized in a chilled mortar and pestle with 2 ml of 0.5 M borate buffer (pH 8.5), containing 150 ltM chloramphenicol and 1 mm dithiothreitol, per g fresh weight of tissue. The homogenate then was centrifuged at 40,000g for 10 min at 4 C, and the resulting supernatant was the crude enzyme extract. The extract was then brought to 25% (v/v) acetone with the addition of ice-cold acetone. After setting in an ice bath for 10 min, the 25% (v/v) acetone-crude extract was centrifuged at 10,000g for 10 min. The supernatant was then brought to 60% (v/v) acetone, allowed to set for 10 min in an ice bath and then was centrifuged at 10,000g for 10 min. The resultant supernatant was discarded, and the pellet was resuspended in 0.5 M borate buffer (pH 8.5) in a total of one-sixth of the original volume of crude extract. This suspension was then centrifuged at 40,000g for 10 min, and the resulting goldyellow colored supernatant was used as the acetone-precipitated enzyme fraction. In some studies, the acetone-precipitated enzyme was added to a column of hydroxylapatite (1.6 x 17 cm) which was previously equilibrated with 0.02 M KH,PO4-Na2HPO, buffer at pH 8.5. The column was then washed with 70 ml of 0.05 M sodium-potassium phosphate buffer (pH 8.5) and 50 ml of 0.08 M sodium-potassium phosphate buffer (pH 8.5). The enzyme was then eluted with 0.15 M sodium-potassium phosphate buffer...

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“…by blending in buffer, the yield at pH 9 was double that at pH 2 ·8. They attributed this to synthesis of IAA at the higher pH through oxidation of endogenous tryptophan by quinones, a reaction described by Gordon and Paleg (1961). These workers found that the reaction tryptophan ~ indolepyruvic acid -+ indoleacetic acid occurred spontaneously in vitro at pH 8 and above, and at pH 6 and above when phenolase was present.…”

Section: Introductionmentioning

confidence: 94%

Indoleacetic Acid in Cambial Tissue of Radiata Pine

Shepherd¹,

Rowan²

1967

Aust. Jnl. Of Bio. Sci.

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The major growth substance detected by mesocotyl bioassay in extracts from cambial tissue of mature radiata pine (Pinus radiata D. Don) was identified as indoleacetic acid by movement on chromatograms and electrophoretograms, by Salkowski test, and by absorption and fluorescence spectroscopy. Indoleacetic acid concentration increased in the top stem in late winter and in the mid and lower stem in mid-spring, consistent with auxin moving down the stem at this time. Since material chromatographically similar to indoleacetic acid was not formed when [ 14C]tryptophan was added to the extracting medium, the indoleacetic acid was not formed by oxidation of tryptophan during extraction.

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Formation of auxin from tryptophan through action of polyphenols

Cited by 105 publications

References 22 publications

Biosynthesis of Indoleacetic Acid from Tryptophan-¹⁴C in Cell-free Extracts of Pea Shoot Tips

Biosynthesis of Indoleacetic Acid from Tryptophan-¹⁴C in Cell-free Extracts of Pea Shoot Tips

Properties of an Aminotransferase of Pea (Pisum sativum L.)

Indoleacetic Acid in Cambial Tissue of Radiata Pine

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Formation of auxin from tryptophan through action of polyphenols

Cited by 105 publications

References 22 publications

Biosynthesis of Indoleacetic Acid from Tryptophan-14C in Cell-free Extracts of Pea Shoot Tips

Biosynthesis of Indoleacetic Acid from Tryptophan-14C in Cell-free Extracts of Pea Shoot Tips

Properties of an Aminotransferase of Pea (Pisum sativum L.)

Indoleacetic Acid in Cambial Tissue of Radiata Pine

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Biosynthesis of Indoleacetic Acid from Tryptophan-¹⁴C in Cell-free Extracts of Pea Shoot Tips

Biosynthesis of Indoleacetic Acid from Tryptophan-¹⁴C in Cell-free Extracts of Pea Shoot Tips