Topic
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.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: Recycling of mature stock to produce a stream of useable shoots for subculturing and eventual stabilization is of great value and can possibly be generalized as an isolation protocol especially for woody species.
Abstract: Murashige and Skoog’s (MS) basal medium with benzylaminopurine (BA), kinetin (KN), zeatin (Z), and thidiazuron (TDZ) were tested for induction of multiple shoots from mature-tree-derived axillary meristems of Pongamia pinnata. Sprouting of buds was 64% on medium devoid of plant growth regulators (PGR). Incorporation of BA, KN, or Z was ineffective in enhancing sprouting frequency or induction of multiple shoots. Sprouting was completely suppressed in the presence of TDZ. Caulogenic buds appeared in nodal meristems of these explants after withdrawal of TDZ. The number of shoot buds was more on explants precultured in higher concentrations. At higher concentrations of this PGR, a swelling developed at the axil. Multiple shoot primordia appeared and differentiated from this swelling after culturing these explants on MS medium for six passages of 2 wk each. Shoots were harvested and cultured on 0.45 μM TDZ for further proliferation. Primary explants after harvesting of shoots were identified as ‘stump’. Reculturing of stumps on 0.45 μM TDZ produced more shoots. This step was followed for six cycles to obtain additional shoots in each cycle. Shoots maintained on 0.45 μM TDZ elongated and rooted (70%) on growth regulator-free medium. Rooted shoots (65%) survived transfer to a sand/soil mixture. This report describes the protocol for micropropagation of P. pinnata using mature-tree-derived nodal meristems. Recycling of mature stock to produce a stream of useable shoots for subculturing and eventual stabilization is of great value and can possibly be generalized as an isolation protocol especially for woody species. Repeated proliferation of caulogenic buds from the same origin may also find application in rescue of endangered germplasm.
27 citations
••
TL;DR: This study demonstrated variation in response among species of the same family, with D. flexuosus responding to BA and TDZ and B. tetraphyllum responding only to 2,4-D.
Abstract: Rushes are important understorey species and comprise a significant component of pre-mined ecosystems. Re-establishment of rushes into disturbed sites has often been problematic. Several cytokinins and thidiazuron were investigated for the stimulation of somatic embryogenesis in key members of the Restionaceae. Somatic embryogenesis was observed for Desmocladus flexuosus (R.Br.) B.G.Briggs & L.A.S.Johnson with benzyladenine (BA) at 1, 5 or 15 μM alone and 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The response to zeatin (Z) and 2iP-6-γ-γ-dimethyl-allyamino-purine (2iP) was negligible. For Baloskion tetraphyllum (J.J.H. de Labillardiere) B.G.Briggs & L.A.S.Johnson and Lyginia imberbis R.Br., BA, Z and 2iP were ineffective in stimulating any response. Somatic embryogenesis was achieved for B. tetraphyllum on 1/2-strength Murashige Skoog (1/2 MS) + 1 μM 2,4-D, with an estimated 14 000 somatic embryos produced from 1 g of plant material. All somatic embryos converted into plantlets and were successfully transferred to soil. Investigation of thidiazuron (TDZ) at 5 and 10 μM and 1 μM 2,4-D demonstrated that young coleoptiles (5–7 days) of B. tetraphyllum produced significantly more somatic embryos (168-fold more) than did older coleoptiles (>14 days). For D. flexuosus, leaf basal portions produced somatic embryos on 5 and 10 μM TDZ, and 5 μM TDZ + 1 μM 2,4-D. Proliferation of 'secondary somatic embryos' was also successful when somatic embryos were initiated on 10 μM TDZ and transferred to 1/2 MS (~9-fold increase). This study demonstrated variation in response among species of the same family, with D. flexuosus responding to BA and TDZ and B. tetraphyllum responding only to 2,4-D. The protocol investigated has the potential to be commercially viable with over 14 000 somatic embryos produced in 6 weeks for B. tetraphyllum.
27 citations
••
TL;DR: Immunoaffinity chromatography, HPLC, ELISA and RIA have been employed to detect cytokinins in autoclaved yeast extract and yeast tRNA and this material should be used with caution in studies of cytokinin production by phytopathogenic bacteria.
27 citations
••
TL;DR: High-performance liquid chromatography, immunochromatography, and radioimmunoassay were used to identify cytokinin-like bases and glycosides in xylem sap of Douglas-fir.
Abstract: Summary High-performance liquid chromatography, immunochromatography, and radioimmunoassay were used to identify cytokinin-like bases and glycosrdes in xylem sap of Douglas-fir (Pseudotsuga menziesii (Mirb.) France). Isopentenyladenosine-type (isopentenyladenine and isopentenyladenosine) and zeatin-riboside type (zeatin, zeatin riboside, and dihydrozeatin riboside) cytokinins were detected during springtime. A glucosyl conjugate of zeatin riboside was also present in small amounts. Levels of cytokinin-like compounds varied throughout the spring but were generally highest in late April to early May.
27 citations
••
TL;DR: It seems that each of the cytokinins studied is active per se and that there is no common, active metabolite between them.
27 citations