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.

Photoregulation of morphogenesis of tobacco plants transformed with the gene of human interlenkin-18

Abstract: The effects of blue light (BL), green light (GL), and red light (RL) on morphogenesis photoregulation of transgenic tobacco (Nicotiana tabacum L.) plants containing a copy of human interleukin-18 gene were studied. Wild-type and transgenic (Il1 No.87–1 and Il18 No.7–11) lines and derived calluses were used. Photomorphogenesis of transgenic lines under GL and RL differed substantially from that of initial line at early stages of morphogenesis; this was expressed in hypocotyl lengthening under GL and cotyledon enhanced expansion under RL. Growth responses to light quality were related to changes in the levels of zeatin, IAA, and ABA. Thus, hypocotyl lengthening and increased cotyledon area under GL occurred at the elevated level of IAA and reduced level of ABA. Growth of callus cells in transgenic lines during zero passage differed from wild-type calluses only in darkness. The data obtained indicate that tobacco plant transformation with the human interleukin-18 gene changed functioning of the photoregulation systems at early developmental stages. This phenomenon is evidently explained by the pleiotropic effects of the gene inserted.

Somatic Embryogenesis from Egyptian Rice (Oryza sativa L.) Mature Zygotic Embryos As Influenced by A Function of Genotype and Growth Regulators

Abstract: Six agronomically and genetically different rice (Oryza sativa L.) cultivars (Giza 171, 172, 173, 175, 177 and 178) were examined for genotype specificity to different growth regulators (2,4Dichloro-phenoxyacetic acid, Benzyladenine, Kinetin and Zeatin) requirements for somatic embryogenesis and plant regeneration from mature zygotic embryos. Embryogenic callus formation, somatic embryo development and no. of somatic embryos (S.E.) per explant were examined as separate traits to measure rice cultivars (genotypes) response in vitro. The response frequency was scored as the percentage of no. of responsive to cultured explants. Two-way analysis of variance of the arcsin-transformed data revealed significant differences between genotypes, treatments (growth regulators) as well as significant GxE. Also, the number of somatic embryos per explant significantly differed between cultivars (genotypes) and between media within genotypes. Over all media examined, Giza 177 cv. was the most responsive in terms of the three traits (74.4, 68.8 and 2.9, respectively ) while Giza 173 was the least (54.8, 48.3 and 2-0, respectively). The auxin 2,4-D proved critical for rice somatic embryogenesis. Cytokinins enhanced in vitro response of the less responsive genotypes, (e.g. Giza 171, Giza 173 and 178), while reduced that of the highly responsive (e.g. Giza 177). A positive correlation existed between regeneration ability and the percentage of japonica genotype in the examined cultivars. A significant quadratic regression was found between regeneration ability and the percentage of japonica genome in the examined cultivars. The results illustrate the influence of the rice genotype on in vitro response. The more predominant the japonica background, the higher the in vitro response, compared with indica background. Moreover, based on the quadratic regression curve presented here, the regeneration ability could be predicted for a given rice cultivar provided the percentage of japonica genome is known.

An improve method for somatic embryogenesis of Schisandra chinensis (Turcz.) Baillon.

Abstract: A somatic embryogenesis protocol for plant regeneration of Schisandra chinensis (Turcz.) Baillon was established. Increased callus induction was obtained from mature zygotic embryos on Murashige and Skoog (MS) medium supplemented with 1.0 mg L(-1) N-phenyl-1,2,3-thidiazol-5-yl-urea (TDZ) or 2.0 mg L(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). Addition of Zeatin (Zt) promoted the formation of embryogenic calli. To induce somatic embryogenesis, 2,4-D, TDZ and Zt were incorporated in the medium alone or in combination. Development of the maximum number of somatic embryos (81 globular, 37 heart, 52 torpedo and 37 cotyledon-stage) and germination of the highest number of embryos (50%) was observed on 1/2 MS medium supplemented with 1.0 mg L(-1) TDZ and 0.2 mg L(-1) Zt. Further development of somatic embryos into plantlets was completed in 1/2 MS medium free of plant growth regulators.

Mass spectrometric determination of cytokinins in the top of tobacco plants using deuterium-labeled standards.

Abstract: Penta-deuterated zeatin, ribosylzeatin, and glucosylzeatin were prepared by the condensation of 6-chloropurine, 9-beta-D-ribosyl- and 9-beta-D-glucosyl-6-chloropurine, and 4-hydroxy-3-methyl-2-butenylamine-d5 derived from acetone-d6. The deuterium contents of these compounds were approximately 96%. Zeatin, ribosylzeatin, N6-isopentenyladenosine and 2-methylthio-ribosylzeatin in the top of tobacco plants were quantitated by mass spectrometry using deuterium-labeled standards.