Cytokinin Translocation and Metabolism in Lupin Species. I. Zeatin Riboside Introduced Into the Xylem at the Base of Lupinus angustifolius Stems

1987 ◽  
Vol 14 (6) ◽  
pp. 695 ◽  
Author(s):  
PE Jameson ◽  
DS Letham ◽  
R Zhang ◽  
CW Parker ◽  
J Badenoch-Jones

The principal cytokinins in xylem exudate of blue lupin (Lupinus angustifolius L.) identified by radioimmunoassay and mass spectrometry were zeatin riboside (ZR), dihydrozeatin riboside and zeatin, but cytokinin O-glucosides and nucleotides were also present. Radioactive [3H]ZR was supplied to the transpiration stream of both derooted and intact blue lupin plants. The distribution of methanol-extracted radioactivity throughout the shoot and the identities of 3H-labelled metabolites were determined; for the latter work, a new bilayer thin-layer chromatography system was developed. In derooted plants supplied with ZR for about 20 h, radioactivity per unit fresh weight of tissue was greatest in the peduncle, stem and axillary shoots and least in the seed. Differences in metabolism were more marked between tissue types than within tissues of different maturity. The principal metabolites in derooted plants (ZR supplied for up to 24 h) were: in laminae, O-glucosyldihydrozeatin, lupinic acid, dihydrozeatin riboside and adenosine; in petioles, dihydrozeatin riboside and adenosine; in pod walls, cytokinin nucleotides, dihydrozeatin riboside, adenine and adenosine; in developing lateral shoots, cytokinin nucleotides; in stem, dihydrozeatin riboside, dihydrozeatin and cytokinin nucleotides. Apart from adenosine, no metabolites could be identified with certainty in seed. In experiments with intact plants conducted over a longer period (plants extracted 2 days after 30 h uptake), metabolism was more extensive but, in all tissues except seed, low percentages of radioactivity were still due to metabolites with an intact zeatin moiety (most frequently O-glucosyldihydrozeatin and lupinic acid). Free zeatin and dihydrozeatin were not found in any tissue and their ribosides were detected with certainty only in pod walls (<2% of extracted 3H). Extraction with 0.5 N KOH after extraction with methanol yielded, on average, an additional equal amount of radioactivity due to nucleotides of adenine and guanine. Features of the translocation studies include: (1) the direct lateral movement of ZR and/or related cytokinins from xylem to bark which was established by bark ringing experiments; (2) the relatively high level of radioactivity per unit tissue fresh weight in developing lateral shoots; (3) the lack of appreciable movement to the seed although the cytokinin reached the pod walls and was partially conserved there; (4) the disproportionately high retention of radioactivity by the petioles which increased with leaf age; (5) changes in ZR metabolites in laminae associated with age; (6) the detection of a new nucleotide metabolite of ZR in pod walls, bark and lateral shoots; this appears to be a transient metabolite with an intact ZR moiety and may be involved in ZR uptake and/or transport. The studies of ZR translocation and metabolism are discussed in relation to sequential leaf senescence, the proposal that developing seeds accumulate xylem cytokinins, and the origin of phloem cytokinins.

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Anna Korus ◽  
Emilia Bernaś ◽  
Jarosław Korus

The aim of this study was to evaluate the quality and health-promoting constituents of several variants of kimchi obtained from Chinese cabbage, kohlrabi, white radish, and cucumbers. The level of dry matter, total soluble solids, ash, total acidity, pH, dietary fiber, and vitamins C, B1, and B2, as well as total polyphenols (TP) and antioxidant activity AA (ABTS, DPPH) in kimchi, were determined. In addition, color parameters were determined ( L ∗ , a ∗ , b ∗ , C ∗ , and h o ). Kimchi with the highest proportion of Chinese cabbage (63%) had the highest levels of dry matter (11.01 g), ash (2.57 g), and vitamins: C, B1, and B2 (51 mg, 52 μg, and 242 μg, respectively), expressed per 100 g of fresh weight. In addition, this product showed the highest total AA of 132.3 μmol Tx/g (ABTS) and 49.7 μmol Tx/g (DPPH) due to its high level of TP (194 mg/100 g). Cucumber-derived kimchi (85%) also had a high content of TP (147 mg/100 g) and high AA of 88.7 μmol Tx/g (ABTS) and 36.3 μmol Tx/g (DPPH). Additionally, stuffed kimchi from kohlrabi (88%) had the highest amounts of total dietary fiber, 3.65 g/100 g fresh weight. In all products, red ( a ∗ ) and yellow ( b ∗ ) were the dominant colors, with values of L ∗ ranging between 32.63 and 53.16. In general, our studies have shown that depending on the raw materials used, kimchi is a good source of dietary fiber but also vitamins and polyphenols.


1974 ◽  
Vol 1 (2) ◽  
pp. 183 ◽  
Author(s):  
KF Faull ◽  
BG Coombe ◽  
LG Paleg

Two gibberellins, one GA1-like, the other GA3-like, were identified in the extracts of roots and tops of 8-,11- and 15-day-old barley seedlings by paper chromatography, paper electrophoresis, thin-layer chromatography, gas-liquid chromatography and bioassay procedures, followed by combined gas chromatography-mass spectrometry. The amounts of gibberellins in the seedlings ranged from 7 to 11 ng per plant. The concentrations of gibberellins in the seedlings were 32-320 ng/g dry weight and 5-28 ng/g fresh weight; concentrations in the roots were higher than those in the shoots.


Weed Science ◽  
1982 ◽  
Vol 30 (3) ◽  
pp. 316-320 ◽  
Author(s):  
Joaquim J.V. Rodrigues ◽  
A. Douglas Worsham ◽  
Frederick T. Corbin

Glyphosate [N-(phosphonomethyl)glycine] applied at 1.1 kg/ha to wheat [Triticum aestivum(L.) ‘Arthur 71′] plants increased height and fresh weight of soybean [Glycine max(L.) Merr. ‘Ransom′] seedlings planted in the pot at time of application of the glyphosate as the number of wheat plants treated increased from 5 to 30/pot. Height and fresh weight of the soybean seedlings also increased as the rate of glyphosate applied to wheat plants (5/pot) increased from 1.1 to 6.7 kg/ha. Increasing the rate of glyphosate from 1.1 to 6.7 kg/ha, however, reduced the height and fresh weight of soybeans when 30 wheat plants/pot were treated. In addition, when 6.7 kg/ha of glyphosate were applied to wheat plants, soybean-seedling plant height and fresh weight decreased as the density of wheat plants per pot increased from 5 to 30. The14C-glyphosate exuded into the soil from treated wheat plants was characterized by thin-layer chromatography. Trace amounts of the radio-label were present on thin-layer plates of leaf and stem extracts of corn (Zea maysL.) plants, which were growing in the same pots with the treated wheat plants. The zone of activity had the same Rf value as the glyphosate standard.


1981 ◽  
Vol 8 (3) ◽  
pp. 307 ◽  
Author(s):  
JS Pate ◽  
P Farrington

Assimilate distribution in Lupinus angustifolius was studied during 7 weeks after emergence of the main inflorescence by feeding [14C]urea to a single leaf or group of leaves on a plant and measuring 14C in plant parts 24 h after feeding. Nine times of feeding were involved, each with 14C treatments encompassing leaves of the main stem and first-order laterals. The inflorescence was a minor sink for assimilates compared with root, main stem and developing lateral shoots. During the first 4 weeks the inflorescence relied on main stem leaves, especially the upper leaves, but in the fifth week leaves of upper laterals became principal sources of assimilates. The transition occurred after four to six basal fruits had set, and just as upper flowers were commencing to abscise. Estimates were made of transfer of photosynthetically fixed carbon from the uppermost main stem leaf to the inflorescence, using data on carbon dioxide exchange and changes in carbon content of this leaf and its translocatory commitment to the inflorescence as determined by 14C feeding. Assimilate flow from leaves to flowers was confined largely to organs of the same or adjacent orthostichies (2/5 phyllotaxis), but these affinities became less definite during fruiting. Import of 14C by reproductive units was related to phenology, position on an inflorescence, and accumulation of dry matter. All flowers attracted assimilates strongly at the bud stage but lost sink strength progressively after opening. Upper flowers destined to abscise failed to import assimilates or to bleed from phloem for several days before being shed. Lower flowers which set fruits showed a rapid resurgence of sink strength once their corollas had senesced and the young fruits had commenced to elongate.


1993 ◽  
Vol 44 (8) ◽  
pp. 1799 ◽  
Author(s):  
CA Atkins ◽  
A Pigeaire

Exogenous application of a 2 mol m-3 buffered solution of N6 benzylaminopurine (BAP) to flowers on the main stem inflorescence of Lupinus angustifolius L, cv. Danja profoundly altered reproductive development by reducing post-anthesis abscission of flowers and small pods. The same effect of BAP was recorded for a mutant (abs-) of cv. Danja, in which organ abscission was completely absent, indicating that localized application of cytokinin enhanced reproductive development rather than reduced pedicel abscission per se in the parent line. Application to pedicel and sepals at the open flower stage completely eliminated flower abortion on the main inflorescence, compared with less than 50% pod initiation on untreated inflorescences, more than doubled final pod yield on the main inflorescence and increased the number of mature pods on the whole plant by 33%. A single dose of BAP, to an inflorescence which bore flowers ranging in their stage of development from post-anthesis to immature flower buds, significantly increased the number of pods initiated and at final harvest, measured on a per plant basis. A number of synthetic and naturally occurring cytokinins, including zeatin riboside and dihydrozeatin riboside, were also effective. BAP application induced a longer period of flowering and resulted in a considerably thickened raceme. This was most marked at the distal end which showed enhanced cambial development and secondary vascularization compared with untreated controls. The positive effects of BAP application on pod initiation were not restricted to cv. Danja but were found also for cv. Warrah and cv. Gungurru, both of which have enhanced pod set compared with Danja. Enhanced pod initiation on the main inflorescence generally reduced the number of pods developing on branch inflorescences. Additional application of BAP to flowers on branches, even at the most opportune time and at the most effective site, did not enhance pod initiation and, in some cases, significantly reduced pod set on these branches. The data indicate that it would be very difficult to exploit the positive effect of exogenous cytokinin application on pod set in field crops of lupin. However, selection or genetic engineering of plants with higher levels of endogenous cytokinins in flowers or flower parts at anthesis may provide a means by which to assess the importance of this factor in determining yield stability.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 657e-657
Author(s):  
Michael R. Evans ◽  
Andrew A. Waber

Euphorbia pulcherrima `Freedom' (poinsettia) and Pelargonium ×hortorum `Pink Elite' (geranium) were grown in 75:25:0, 50:50:0, 27:75:0, 75:0:25 50:0:50, 25:0:75 (v/v sphagnum peat: 0.25-grade rubber: 0.10-grade rubber) substrates or in a 50 sphagnum peat: 30 perlite: 20 loam (v/v) standard greenhouse substrate. Geranium root and shoot fresh weights, height, and number of axillary shoots were reduced when grown in rubber-containing substrates compared to plants grown in the standard control. As the proportion of either grade of rubber increased, root and shoot fresh weights, height, and number of axillary shoots decreased. Flowering in geranium was delayed and the number of inflorescences reduced as the proportion of the 0.10-grade rubber increased. Plants grown in the 0.25-grade rubber failed to flower by the termination of the experiment. Poinsettia plants grown in rubber-containing substrates had reduced shoot fresh weight, height, number of bracts, and bract area compared to plants grown in the standard control. As the proportion of either grade of rubber increased, height, shoot fresh weight, number of bracts, and bract area decreased. Number of axillary branches was reduced in substrates containing 50% and 75% of the 0.10-grade rubber. Days to anthesis was unaffected by substrate.


2013 ◽  
Vol 48 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Eleonora Gabryszewska ◽  
Ryszard Rudnicki

The effect of white, blue, green, red and UV + white light on the growth and development of shoots and roots of Gerbera jamesonii cv. Queen Rebecca in relation to the presence of kinetin or IAA were investigated. The highest number of axillary shoots was obtained in red and green light on the medium with 5 mg l<sup>-1</sup> kinetin. Also, green and red light markedly increased the number of leaves developed on the plantlets on the medium supplemented with kinetin. Light quality and IAA added to culture medium variously affected the development of root system: roots were regenerated under all light treatments, higher root number was recorded under red light when 5 mg l<sup>-1</sup> IAA was added to the media, the shortest roots were found in red light on the medium supplemented with IAA. The greatest fresh weight of shoots was found under white light on the medium with kinetin. Red light markedly decreased shoot fresh weight on hormone-free medium. Blue and white light caused increase in fresh weight of roots.


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