The trans-zeatin and other phytohormones are used as growth regulators to be induced in plants. Their presence has been determined in corn grains and some plant species, but not in their waste or liquid organic fertilizers, so the objective of this investigation was to quantify the compound by high performance liquid chromatography (HPLC). Ethanol extracts of corn waste and bioinsumos were prepared. Were identified by thin layer chromatography on aluminum chromatoplates Merck 60 F254 10x10cm as stationary phase and methanol- acetonitrile (80:20) as mobile phase. Their quantification was performed by HPLC on a C18 column, 250mm x 4 mm (5 μm), and methanol-water (40:60) acidified 5% acetic acid as mobile phase, 0.8 mL.min-1 flow rate and wavelength of 280 ηm. The extract of corn grains was taken as control. Statistical analysis to validate the results obtained was performed in the InfoStac software. The control sample was found to have the highest concentration of trans-zeatin (0.730 mg / g). These results have not been referenced in the literature and allow adding ecological and economic utility of this type of agricultural waste.
Abstract The mechanism of differentiation of tracheid (earlywood or latewood) should be elucidated to improve the wood properties of sugi trees (Cryptomeria japonica). Water deficit affects tracheid differentiation in conifers. However, the signals, which transmit the information of water contents in the soil to the differentiating tracheid, remain unknown. Plant responses with deficits of macronutrients or water showed some differences but also similarities, mostly involving hormonal long-distance sig- naling. In Arabidopsis, trans-zeatin (tZ)-type cytokinins play a role as a root-to-shoot acropetal signal. In this study, we report the effects of applying tZ alone or in combination with other phytohormones on tracheid differentiation in mature sugi trees forming latewood. The application of tZ induced the formation of earlywood-type tracheids with significantly smaller cell wall ratios and larger microfibril angles than those of controls in July, August and Septem- ber. The application of indole acetic acid (IAA) in com- bination with tZ inhibited the effects of applied tZ, although gibberellic acid (GA3) did not. In October and November, application of tZ could not affect the xylem formation or dormancy of cambium. We hypothesized that tZ might play a role in the differentiation of earlywood tracheid.
Although it has been repeatedly reported that exogenous auxin does not promote axillary shoot proliferation, a low concentration of auxin together with a relatively high level of cytokinin is often useful during shoot multip- lication  . Such an effect was observed in the present study that, the combination of BAP and IAA pro- duced best response. When a relatively low concentration of IAA is combined with high BAP than both in- creased or both decreased (Table 2). The maximum rate of shoot induction was achieved on an MS medium supplemented with the combination of 4.5 mg/l BAP and 0.5 mg/l IAA (77.5% ± 5.00%) and Ms medium con- taining eight mg/l Zeatin (67.50% ± 5.00%) for nodal and shoot tip explants respectively (Table 2). The second best ranked media for effective shoot bud induction was found to be MS medium added with eight mg/l Zeatin (70% ± 0.00%) and 4.5 mg/l BAP alone (62.50% ± 5.00%) for nodal and shoot tip explants respectively.
This review chronicles the development of the cytokinin research during the last 30 years. Cytoki- nin and auxin are the two major plant growth hormones that control virtually all aspects of growth and development in higher plants. The pathways for cytokinin biosynthesis and metabol- ism have been characterized by the identification of isopentenyl pyrophosphate transferase, cyto- kinin oxidases, cytokinin hydroxylase, zeatin cis-/trans-isomerase, cytokinin phosphoribosyl hy- drolases, cytokinin-specific riboside phosphorylase, and others enzymes. Loss-of function mutant phenotypes of cytokinin degradation/activating enzymes indicate the regulation of concentration and spatial distribution of bio-active cytokinin plays a pivotal role in the increase in panicle size, in the numbers of floral organs, and eventually in seed yield. One of the most fundamental ques- tions in the cytokinin field is one concerning the prevalence of cis-zeatin in monocotyledonous crops (rice and maize) and in dicotyledonous legumes (pea, chickpea) and potato/sweet potato. A hypothesis is that cis-zeatin is synthesized by the cis-specific hydroxylation of the terminal methyl group of N 6 -isopentenyl side chain of N 6 -isopentenyl adenosine (i 6 Ado) or of their mono-, di-, or
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Crotalaria hebecarpa is a small unexplored prostate herb belonging to the family Fabaceae. Though the identity and distribution of the plant is known, but its phytochemical and nutritional composition and their biological activities are not known. Since nothing is known about this plant, establishment of in vitro plants and bio mass enables us to use it for phytochemical and pharmacological exploration. In this paper, we for the first time are reporting the in vitro response of seeds, shoots and roots cultured on MS medium supplemented with different phyto hormones. The seeds cultured on MS medium supplemented with KN (4mg/l) produced shoots (Mean length, 9.23cm) while on Zeatin supplemented medium produced shoots and roots with mean length of 10cm and 7cm respectively. Maximum percentage of callus from leaf explants was observed at 3 mg/l of NAA (90%) and from roots at 2 mg/l Zeatin (95%). Maximum number of multiple shoots from callus was observed at 5mg/l BA (7.01±0.21) and at 4 mg/l of KN (5.45±0.64). The work in continuation to this preliminary report needed to be conducted to complete micro propagation process and to establish cell or cell suspension system for secondary metabolite production.
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regulators was demonstrated in the present multi- plication experiments in the snowdrop anemone. The quality of the snowdrop anemone shoots was determined by the type of cytokinin and the geno- type. Shoots from media supplemented with BA were inferior to those supplemented with zeatin and kinetin. Hyperhydricity and malformed leaves were observed in the AS4 clone, although BA was applied at a relatively low level (1 µM) (Fig. 1C). Moreover, red leaves (under stress conditions) were observed in this clone when it was grown in PGR- free medium (Fig. 1B). Cytokinins have been shown to induce hyperhydricity in many species, usually in a concentration-dependent manner when other conditions in the culture system are not optimised (Ivanova, Van Staden 2008). The aromatic cy- tokinin BA remains the most widely used cytoki- nin in commercial micropropagation worldwide, but it may have several side effects, such as diffi- culty in rooting, toxicity, hyperhydricity, stunted shoots and callus formation (Magyar-Tábori et Table 2. Effect of different factors (genotype and medium composition) on shoot regeneration of snowdrop anemone
Results: Here we report the development of a MT near-isogenic genotype harboring the allele Rg1 (MT-Rg1), which greatly improves tomato in vitro regeneration. Regeneration was further improved in MT by including a two- day incubation of cotyledonary explants onto medium containing 0.4 μ M 1-naphthaleneacetic acid (NAA) before cytokinin treatment. Both strategies allowed the use of 5 μ M 6-benzylaminopurine (BAP), a cytokinin 100 times less expensive than zeatin. The use of MT-Rg1 and NAA pre-incubation, followed by BAP regeneration, resulted in high transformation frequencies (near 40%), in a shorter protocol with fewer steps, spanning approximately 40 days from Agrobacterium infection to transgenic plant acclimatization.
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about 4–20% calli differentiated into shoots de- pending upon the type of the explant and growth regulators used (Figs. 1B and c). in the present investigation, out of 27 treatments used, the calli were differentiated into shoots only on the medium supplemented with 2 mg/l tDZ and zeatin alone or together with Naa and iaa and with 2 mg/l kinetin and 1 mg/l iaa. The rest of the treatments were in- effective in differentiating calli (table 2). This might have resulted from the imbalance in exogenous cy- tokinin-auxin ratio or endogenous level of growth regulators. Frey and Janick (1991) reported that the explant source and the balance of plant growth regulator influenced shoot regeneration in carna- tion. Shiba and Mii (2005) reported the difficulty in differentiating shoots from calli in most Dianthus species, especially carnation (Nakano, Mii 1992). The highest callus differentiation (21.33%) was ob- served with 2 mg/l zeatin and 1 mg/l iaa, which differs significantly from the other treatments. Ja- gannatha et al. (2001) found MS medium supple- mented with 10 µ M kinetin as the best medium for in vitro propagation of carnation cv. Sterile Dop. Maximum frequency of shoots from leaf segment derived calli was achieved with 0.6 mg/l tDZ and 1.2 mg/l zeatin in carnation (Kumar et al. 2006). The best interaction on callus differentiation was achieved with 2 mg/l zeatin and 1 mg/l iaa in leaf explants and with 2 mg/l zeatin or tDZ and 1 mg/l iaa in the internode explants and are statistically on a par with each other (table 2).
Similarly, a percentage of 100% callus formation was also observed in all treatments of Zeatin after 8 weeks of culture where callus formed were observed to be semi-friable and yellowish in colour. These observations indicated that Zeatin is indeed more efficient in inducing callus than shoots for Ficus carica cv. Japanese BTM 6. These results correlates with the work of Samuelson and Larsson (1993) whereby they reported the efficiency of Zeatin as a cytokinin for callus formation of woody plants.
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The data presented in figure-1 revealed that different PGRs have significantly affected percent shootings in seedling explants of guava. Explants cultured on MS with 1.0 mgl -1 BA in combination with 0.5 mgl -1 zeatin gave maximum (48%) shooting. With the same combinations when the concentration of cytokinin was doubled the shooting frequency reduced to 37%. Twenty two percent explants on MS medium with1.0 mgl -1 BA responded to shoot regeneration after seven weeks of culturing.
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The study of the effect of cytokinins on the culture of carob apex showed that zeatin and BAP at low concentrations (0.5 mg/l) are the most favorable for shoots elongation, as well as for neoformation of shoots and leaves. In addition, initiation of the culture of carob apex can be easily established in the presence of moderate BAP concentration, close to 0.5 mg/l, alone or in combination with low concentrations of IBA (0.1 mg/l). Furthermore, WPM macronutrients allow better formation of shoots and leaves than those of MS and, the incorporation of BAP at moderate concentrations, combined with low concentrations of GA 3 ,
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