Kinin Activity From Plant Extracts II. Partial Purification and Fractionation of Kinins in Apple Extract

Zwar, JA; Kefford, NP

doi:10.1071/bi9630407

Cited by 21 publications

(5 citation statements)

References 2 publications

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“…A similar conclusion was reached in an experiment involving 100 mg/l each of sorbitol, myoinositol, and scylloinositol and 0·05, 0-15, 0·5, 0·75 gjml of apple extract purified roth polyamide and by subsequent elution from carbon roth pyridine (Zwar, Bottomley, and Kefford 1963). In tIns case cell division was detected at 0·15 glml of apple extract.…”

Section: Iaa Applesupporting

confidence: 60%

“…for the induction of cell division in tobacco pith blocks is illnstrated in Figure 3. In that experiment, apple fruitlet extract, which had been extracted "~th ethyl acetate at pH 4·5 (this treatment should remove native auxins) and purified roth polyamide resin (Zwar, Bottomley, and Kefford 1963), was tested at 0, 0'1, 0·25, or 0'5gjml (arbitrary uuits described in Section II(d)(iv)) in the absence of auxin or in the presence of 10-7 1\'1 or lO-sM IAA. In the absence of auxin no growth occurred; in the presence of auxin alone cell enlargement occurred.…”

Section: (C) Cold Extraction Of Apple Kininmentioning

confidence: 99%

“…The apple extract had been purified with polyamide, then by displacement roth ammouia from the ion-exchange resin "Dowex 50"-H+ (Zwar, Bottomley, and Kefford 1963). It was used at 0·05, 0'25, and 2·5 gjml.…”

Section: Iaa Applementioning

confidence: 99%

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Kinin Activity From Plant Extracts

Kefford¹,

Zwar²,

Goldacre³

1963

Aust. Jnl. Of Bio. Sci.

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A biological assay for substances inducing cell division is described. Blocks of tobacco stem pith were cultured aseptically on 1 ml of basal medium containing mineral salts, sucrose, and vitamins. The addition of auxin to the basal medium caused cell enlargement, but the addition of kinetin alone produced no reaction. Auxin and kinetin together induced cell division, l'esulting in nests of cells readily distinguishable visually from the original cells. Callus produced in this way could be subcultured indefinitely on medium containing bot,h 3-indolylacet,ic acid (IAA) and kinetin.When tobacco pith was cultured on basal medium plus IA..<\.., cell division was induced by extracts of a number of plant mel'istematic tissues added as supplements. Auxin was necessary for the reaction. Active extracts were obtained from fruitlet t.issues of apple, quince, pear, and plum harvested at various times after pollination.Extracts of seeds, placenta, and carpel wall of tomato at various stages of development were assayed for ability to induce cell division. Such ability was detected in extracts of cambium from stems of P1''nUS rnrliatn, Eucalyptus regnmlloi, and Nicotiana, tabacum.The cell-division response of tobacco pith to apple·fruitlet extract was not enhanced by the addition of polyols or casein hydrolysate, alone or in mixtures, to the culture medium. The response to kinetin wa!'; not enhanced b~' the addit.ion of nrea or sorbitol alone or in combination!';.

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Section: Iaa Applesupporting

confidence: 60%

Section: (C) Cold Extraction Of Apple Kininmentioning

confidence: 99%

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Kinin Activity From Plant Extracts

Kefford¹,

Zwar²,

Goldacre³

1963

Aust. Jnl. Of Bio. Sci.

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“…After his lecture, a session of the annual conference of the Australian Society of Plant Physiologists began and the zeatin formula was displayed for the CSIRO cytokinin workers to see. The zeatin structure shown was very probably the key to the unknown apple fruitlet cytokinin being investigated by Kefford and co-workers ( Zwar et al 1963 ). Kefford wrote to Auckland DSIR for confirmation.…”

Section: Purification and Identification Of Cell Division Factorsmentioning

confidence: 94%

Zeatin: The 60th anniversary of its identification

Jameson

2023

Plant Physiology

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While various labs had shown cell division-inducing activity in a variety of plant extracts for over a decade, the identification of zeatin (Z) in 1964, the first known naturally occurring cytokinin, belongs to Letham and co-workers. Using extracts from maize (Zea mays), they were the first to obtain crystals of pure Z and in sufficient quantity for structural determination by MS, NMR, chromatography, and mixed melting point analysis. This group also crystallised Z-9-riboside (ZR) from coconut (Cocos nucifera) milk. However, their chemical contributions go well beyond the identification of Z and ZR and include two unambiguous syntheses of trans-Z (to establish stereochemistry), the synthesis of 3H-cytokinins that facilitated metabolic studies, and the synthesis of deuterated internal standards for accurate mass spectral quantification. Letham and associates also unequivocally identified Z nucleotide, the 7-and 9-glucoside conjugates of Z, and the O-glucosides of Z, ZR, dihydro Z (DHZ) and DHZR as endogenous compounds and as metabolites of exogenous Z. Their contributions to the role of cytokinins in plant physiology and development were also substantial, especially the role of cytokinins moving in the xylem. These biological advances are described and briefly related to the genetic/molecular biological contributions of others that established that plants have an absolute requirement for cytokinin.

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“…Nevertheless, it seemed of interest to determine in how far the kinin in lettuce seed resembles that described by other workers (Miller 1961;Zwar, Bottomley, and Kefford 1963). As source of kinin for these experiments, ethanolic extracts of seeds germinated for 48 hr with a light stimulus were used.…”

Section: Resultsmentioning

confidence: 99%

Short Oommunications Kinins in Germinating Lettuoe Seed

Barzilai¹,

Am²

1964

Aust. Jnl. Of Bio. Sci.

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The presence, in plants extracts, of factors capable of promoting cell division has been known for some time (Goldacre and Bottomley 1959;Miller 1961) and such compounds have been partially purified (Miller 1961; Zwar, Bottomley, and Kelford 1963). The germination of seeds normally involves cell division as well as cell enlargement (Mayer and Poljakolf-Mayber 1963). Therefore it seemed of interest to investigate whether kinins occur in seeds or are formed during their germination. Lettuce seeds were used because their physiology has been studied extensively. We have also tried to partially characterize their kinins. MethodsKinin activity was assayed biologically. The test objects were disks of stem pith from tobacco, Nicotiana tabacum cv. Seratina. The pith was removed from externally sterilized stem sections, taken 20 em from the stem apex. The disks, 2-3 mm in diameter and 2-3 mm thick, were obtained aseptically and were prepared fresh for each experiment. They were floated in petri dishes on culture medium prior to sowiug into erlenmeyer flasks containing 20 ml of medium solidified with agar. The medium was that of Zwar and Skoog (1963), but with their concentrations of inorganic nutrients doubled.Two controls were used: in both 0·2 p.p.m. 3-indolylacetic acid (IAA) was added to the basal medium and in one 0·2p.p.m. of kinetin was also added. In those containing 0·2 p.p.m. kinetin normally 9 out of 10 sections grew, while in those without kinetin growth was absent. When extracts were tested they were substituted for the kinetin. The flasks were kept in the dark at 26'0 and covered with polythene in order to reduce drying out of the culture. IGnin activity was assayed visually by determining whether the pith had undergone cell division after 2-4 weeks Zwar, Bottomley, and Kelford 1963;Zwar and Skoog 1963). Oen division could be easily detected visually and was confirmed by microscopic examination of cells from the disks. Kinin activity is expressed as the number of disks showing cell division in a given number of replicates as compared to controls without kinin.Lots of 1 g of lettuce seeds, cv. Grand Rapids, were germinated in petri dishes with 3 ml water and given a light stimulus of 30 sec exposure to red light after imbibition for I hr, and then placed in the dark at 26'0 (EvenariandNeumann 1953). Mter 48 hr germination was 100%. >I< Manuscript

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Kinin Activity From Plant Extracts II. Partial Purification and Fractionation of Kinins in Apple Extract

Cited by 21 publications

References 2 publications

Kinin Activity From Plant Extracts

Kinin Activity From Plant Extracts

Zeatin: The 60th anniversary of its identification

Short Oommunications Kinins in Germinating Lettuoe Seed

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