Zeatin

About: Zeatin is a research topic. Over the lifetime, 2467 publications have been published within this topic receiving 64092 citations. The topic is also known as: Zeatin & (E/Z)-zeatin.

In vitro Propagation of Crassocephalum crepidioides—An Endangered African Traditional Leaf Vegetable and Molecular Analysis of Micropropagated Plants

Abstract: Crassocephalum crepidioides (Benth) S. Moore is an important African traditional leaf vegetable, but its production is very low and its existence threatened. An efficient and reproducible micropropagation protocol of C. crepidioides was developed from nodal stem segments of pot-grown plants. Shoot induction was obtained on Murashige and Skoog (MS) medium supplemented with benzineamino purine (BAP) alone and in combination with zeatin and naphthalene acetic acid (NAA). Elongated shoots successfully rooted on zeatin alone and in combination with indole butyric acid (IBA). Molecular stability of micropropagated plants was evaluated using random amplified polymorphic DNA (RAPD) markers. Survival of nodal segments in micropropagation medium was greater than 70% in all treatments. The presence of plant growth regulators (PGRs) in MS medium influenced shoot formation, rooting, and number of shoots and roots per explant. The best shoot formation frequency (88.7%), number of shoots per explant (3.7), and s...

Effects of natural and synthetic cytokinin hormone on shoot regeneration of rockmelon (Cucumis melo) Glamour cv. by using nodal explants

Abstract: Rockmelon Glamour cv. belongs to Cucurbitaceae family and the fruit enriched with nutrients that can reduce the risk of cancer, heart disease and asthma. Using in vitro culture technique, rockmelon was able to mass propagate and commercially cultivated in order to meet rising market demand. The objectives of this study were to develop a micropropagation protocol for mass production of new Glamour cv. new plantlets and to acclimatize the plantlets to the ex vitro condition for further growth process. In this research, both natural (zeatin) and synthetic (kinetin) hormones were supplemented in MS media at different concentrations (0, 0.01, 0.1, 1 and 2 mg/L) for shoot proliferation from nodal explants of rockmelon Glamour cv. Shoots were successfully regenerated from node explant in all tested medium after 4 weeks. MS supplemented with 0.1 mg/L kinetin gave the highest number of shoots (1.83±1.89), nodes (4.33±3.31), and leaves (4.11±3.18). Regenerated shoots were transferred to the root induction medium containing IAA at different concentrations (0, 0.01, 0.1, 1 and 2 mg/L) and shoots was highly elongate and root proliferated in MSO. Healthy grown plantlets were acclimatized to three different growth media. In vermiculite growth media, plantlets were successfully survived (81±23.09%) after 6 weeks. In conclusion, kinetin synthetic hormone was able to give high number of shoots regenerated from nodal explants of rockmelon Glamour cv. compared to zeatin and plantlets were able to survive in the external condition in the vermiculite growth media.

Zeatin-binding proteins participating in cytokinin-dependent activation of transcription

Abstract: A new zeatin-binding protein (ZBP) with molecular weight of 67± 2 kD was isolated from cytosol of first leaves of 10-day-old barley plants and revealed by non-denaturing PAGE as a single polypeptide. Its zeatin-binding capacity was established (i) by its ability to bind reversible [3H]trans-Zeatin, (ii) by its interaction with anti-idiotype antibodies (Aba-i) from antiserum raised against zeatin, and (iii) by its ability to displace antibodies to zeatin (Abz) from its complex with immobilized trans-zeatin in competitive ELISA. In concert with trans-zeatin the ZBP activated transcription elongation in the system containing chromatin-bound RNA polymerase I from barley leaves and in isolated nuclei. Our results proved that 67 ± 2 kD ZBP is a receptor of natural cytokinin in leaf cells which mediates cytokinin dependent activation of transcription elongation. ZBP- and mzns-zeatin-indueed activation of RNA synthesis in the system containing chromatin-bound RNA polymerase I depended on leaf age used for chromatin isolation and corresponded to age-dependence of leaf response to cytokinins. ZBP of 70 ± 2 kD was also isolated from the shoots of etiolated 5-day-old maize seedlings. This protein reversibly bound [3H]dihydrozeatin, was recognized by Aba-i isolated from antiserum raised against zeatin and activated RNA synthesis in vitro in the system containing chromatin-bound RNA polymerase from barley leaves in the presence of trans-zeatin. Hence, ZBP-mediated cytokinin-dependent activation of RNA synthesis is not species-specific. Thus, it was discovered the new family of ZBPs with the properties of cytokinin receptor which is involved in cytokinin-dependent activation of transcription elongation in plant cells.

Changes of endogenous hormones in Lilium davidii var. unicolor bulbs during bulb development and storage at low temperature for dormancy release

Abstract: Changes of endogenous hormones in mother scales and in daughter scales of bulbs in Lilium davidii var.unicolor were studied during bulb development and 101 days storage at 2,6 and 10℃ in moist sawdust.The results indicated that ABA concentration both in mother and daughter scales and GA_(3) concentration,ZR concentration in mother scales increased during bulb development,but IAA concentration in all scales and GA_(3) concentration,ZR concentration in daughter scales declined.During the low temperature storage, GA_(3) and IAA level in different parts of bulb had the increase phase, but ABAcontent decreased, and ZR content in daughter scales declined, but which in mother scales had the increase as well as. The notable changes in content of endogenous hormones occurred in the earlier 34 d of storage. Compared among different storage temperature, ABA content had little difference, but GA_(3) content decreased with the rising of temperature. In daughter scales which having plentiful starch, a significantly negative correlation was observed between GA_(3) and ABA content, but had no any correlations in mother scales which had little starch. Path analysis of results showed that metabolism mechanism in mother scales and in daughter scales were different markedly during bulb development and storage at low temperature for dormancy release. Substances changes in mother scales were regulated by endogenous GA_(3), but mostly by endogenous ABA in daughter scales.

Endogenous levels of gibberellins, IAA and cytokinins in Catharanthus crown gall tissues of different tumor types

Abstract: Endogenous levels of gibberellins, auxins and cytokinins in crown gall tissues of Catharanthus roseus G. Don. of two different tumor types, induced by a nopaline-type and an octopine-type Ti-plasmid, were examined