Kinetin

About: Kinetin is a research topic. Over the lifetime, 7856 publications have been published within this topic receiving 135550 citations. The topic is also known as: Kinetin.

Anthocyanin production in callus cultures of roselle ( Hibiscus sabdariffa L.)

Abstract: Callus tissues derived from seedlings of roselle (Hibiscus sabdariffa L.) were shown to produce two cyanidin glycosides as major anthocyanin pigments. Both callus growth and anthocyanin synthesis were remarkably stimulated by 2,4-dichlorophenoxyacetic acid. The highest anthocyanin yield was observed when 1 μM 2,4-D in combination with 0.1–1 μM kinetin was supplemented to the culture medium. In contrast, gibberellic acid showed inhibitory effect on anthocyanin production.

Growth regulator pretreatment improves somatic embryogenesis from leaves of squash (Cucurbita pepo l.) and melon (Cucumis melo l.)

Abstract: Leaf explants of squash (Cucurbita pepo L.) and melon (Cucumis melo L.) were pretreated initially with 113.1, 226.2 or 452.4 µM 2,4-dichlorophenoxyacetic acid (2,4-D), 46.5, 93 or 186 µM kinetin or a combination of both at the above concentrations, for 6, 24 or 48 h. After pretreatment, explants were transferred to an agar-solidified medium that was not supplemented with growth regulators or to a species-specific standard induction medium. Control explants from each species were incubated directly on the species-specific standard induction medium. Initial pretreatment of squash explants with 186 µM kinetin and of melon explants with 226.2 µM 2,4-D for 48 h significantly promoted the formation of somatic embryos which developed further to the torpedo-shape stage and germinated. Under these conditions at least four plants can be regenerated per square centimeter of explant surface, thus achieving an increase over non-pretreated cultures of 143% and 130% for squash and melon, respectively.

In vitro plant regeneration system for Cassia siamea Lam., a leguminous tree of economic importance

Abstract: A method for rapid in vitro propagation of Cassia siamea Lam. using cotyledonary node explants, excised from 14-day old aseptic seedlings, has been established. Murashige and Skoog (MS) medium supplemented with different concentrations of 6-benzyladenine (BA), kinetin (Kn) and thidiazuron (TDZ) singly or in combination with auxins was used for regeneration studies. Among the single treatment of three cytokinins BA at 1.0 µM was found to be optimum for direct shoot regeneration as it induced an average of 8.20 ± 0.66 shoots per explant. The regeneration frequency further enhanced with the application of auxin along with optimal BA concentration. The highest frequency for shoot regeneration (90%), the maximum number of shoots per explant (12.20 ± 0.73) and the maximum shoot length (6.40 ± 0.07) cm were obtained on the medium consisted of MS + 1.0 µM BA + 0.5 µM NAA. Successful in vitro rooting was induced from cut end of the microshoots when placed on half-strength MS + IBA (2.5 µM). The regenerated shoots with well developed root system were successfully acclimatized and established in pots containing sterilized garden soil and garden manure (1:1) and grown under greenhouse conditions with 85% survival rate.

In vitro propagation for the conservation of a rare medicinal plant Justicia gendarussa Burm. f. by nodal explants and shoot regeneration from callus

Abstract: Justicia gendarussa is a valuable medicinal plant and various parts of this plant are pharmaceutically used for the treatment of different diseases. In vitro regeneration of shoot buds was obtained from culture of nodal cuttings as well as shoot regeneration from callus. The nodal cuttings differed in shoot proliferation in terms of percentage of explants that responded and average shoot length with various concentrations (4.4, 8.9, 13.3, 17.7, 22.2 μM) of 6-benzyladenine (BA), kinetin (Kn) and thidiazuron. In all treatments, one shoot was invariably present. Optimum 87% of cultures responded with an average shoot length of 4.4 cm on Murashige and Skoog (MS) medium supplemented with 17.7 μM BA. Callus was induced from the mature leaf segments on MS medium supplemented with Kn (4.7, 13.9, 23.2 μM) alone or in combination with 2, 4-dichlorophenoxyacetic acid (2, 4-D; 2.3 μM, 4.5 μM). Optimum callus induction (78%) was obtained on MS medium supplemented with 14 μM Kn and 4.5 μM 2, 4-D. When the callus was subcultured on MS medium fortified with BA (8.9, 17.7, 26.6 μM) or Kn (9.3, 18.6, 27.9 μM) alone or in combination with α naphthalene acetic acid (NAA; 2.7, 5.4 μM), shoot regeneration was obtained. The highest response (92%) was observed on MS medium containing 17.7 μM BA and 5.4 μM NAA. On this medium, an average number of 12.2 shoots were obtained per responding callus. The shoots obtained from callus and nodal cuttings were rooted with a frequency of 73% on MS medium augmented with 9.8 μM indole-3-butyric acid. The rooted shoots were successfully transplanted to soil and sand mixture (1:1) with 90% survival rate. The protocol standardized for shoot proliferation and regeneration in J. gendarussa from nodal cuttings and leaf-derived callus is suitable for micropropagation and conservation of this essential medicinal plant.

Cytokinin‐Inhibitor Antagonism in the Hormonal Control of α‐Amylase Synthesis and Growth in Barley Seed

Abstract: The effect of cytokinins and gibberellic acid on the inhibition of growth and α-amylase synthesis by germination inhibitors was investigated in intact and embryoless seed halves. The cytokinins, kinetin and benzyladenine, effectively reversed the inhibition of coleoptile growth and α-amylase synthesis by abscisic acid and courmarin in barley seed. An antagonism between cytokinins, kinetin and benzyladenine, effectively reversed the inhibition of coleoptile growth and α-amylase synthesis by abscisic acid and coumarins in barley seed. An antagonism between cytokinins and germination inhibitors was also shown in root growth. Abscisic acid inhibited coleoptile growth to a greater extent than the root growth while the opposite held true in the case of coumarin. The apparent increase in coleoptile growth and α-amylase synthesis by gibberellic acid plus abscisic acid (or coumarins) over abscisic acid (or coumarin) appears to be a result of the overall stimulation of growth and metabolism by exogenous gibberellic acid and probably does not involve an interaction of gibberellic acid with the inhibitors. Gibberellic acid reversed root inhibition to some extent. Abscisic acid inhibition of gibberellic acid induced α-amylase synthesis in the embryoless endosperm was not reversed by excess gibberellic acid or kinetin Cytokinin reversal of inhibition of growth and enzyme synthesis probably depends on some factor(s) in the embryo. Cytokinin reversal of inhibitor action leading to enzymen synthesis and growth may be at the level of genome or at the site protein assembly.