Topic
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.
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TL;DR: In this article, it was concluded that auxins suppress bud development by stimulating ethylene formation, and the possibility that auxin induced ethylene production controlled apical dominance is considered.
Abstract: Indole-3-acetic acid stimulates ethylene production in the nodal region of pea stems, and the gas inhibits bud growth. At all concentrations of IAA there is a close correlation between the intensity and duration of ethylene production and the bud inhibition which results. Kinetin reverses the inhibitory actions of ethylene and IAA on bud growth. It is concluded that auxins suppress bud development by stimulating ethylene formation. The possibility that auxin induced ethylene formation controls apical dominance is considered.
153 citations
TL;DR: In somatic embryogenesis, characteristic stages of zygotic embryonic development were recapitulated and complete embryos were recovered by inhibiting cleavage polyembryony with abscisic acid and culturing individual embryos without growth regulators.
151 citations
TL;DR: In vitro derived shoots were elongated on growth regulator-free MS medium and exhibited better rooting response on medium containing 4.9 μM IBA and almost 100% transplantation success in the field.
Abstract: A mass in vitro propagation system for Bacopa monniera (L) Wettst (Scrophulariaceae), a medicinally important plant, has been developed A range of cytokinins have been investigated for multiple shoot induction with node, internode and leaf explants Of the four cytokinins (6-benzyladenine, thidiazuron, kinetin and 2-isopentenyladenine) tested thidiazuron (68 μM) and 6-benzyladenine (89 μM) proved superior to other treatments Optimum adventitious shoot buds induction occurred at 68 μM thidiazuron where an average of 93 shoot buds were produced in leaf explants after 7 weeks of incubation However, subculture of leaf explants on medium containing 22 μM benzyladenine yielded a higher number (1291) of adventitious shoot buds by the end of third subculture The percentage shoot multiplication (100%) as well as the number of shoots per explant remained the high during the first 3 subculture cycles, facilitating their simultaneous harvest for rooting In vitro derived shoots were elongated on growth regulator-free MS medium and exhibited better rooting response on medium containing 49 μM IBA After a hardening phase of 3 weeks, there was an almost 100% transplantation success in the field
151 citations
TL;DR: The results are a clear indication that O-glucosylation of cis-zeatin is a natural metabolic process in maize and serves as a precursor to the active trans-isomer or has any other unique function.
Abstract: trans-Zeatin is a major and ubiquitous cytokinin in higher plants. cis-Zeatin has traditionally been viewed as an adjunct with low activity and rare occurrence. Recent reports of cis-zeatin and its derivatives as the predominant cytokinin components in some plant tissues may call for a different perspective on cis-isomers. The existence of a maize (Zea mays) gene (cisZOG1) encoding an O-glucosyltransferase specific to cis-zeatin (R.C. Martin, M.C. Mok, J.E. Habben, D.W.S. Mok [2001] Proc Natl Acad Sci USA 98: 5922-5926) lends further support to this view. Results described here include the isolation of a second maize cisZOG gene, differential expression of cisZOG1 and cisZOG2, and identification of substantial amounts of cis-isomers in maize tissues. The open reading frame of cisZOG2 has 98.3% identity to cisZOG1 at the nucleotide level and 97.8% at the amino acid level. The upstream regions contain common and unique segments. The recombinant enzymes have similar properties, K(m) values of 46 and 96 microM, respectively, for cis-zeatin and a pH optimum of 7.5. Other cytokinins, including N(6)-(delta(2)-isopentenyl)adenine, trans-zeatin, benzyladenine, kinetin, and thidiazuron inhibited the reaction. Expression of cisZOG1 was high in maize roots and kernels, whereas cisZOG2 expression was high in roots but low in kernels. cis-Zeatin, cis-zeatin riboside, and their O-glucosides were detected in all maize tissues, with immature kernels containing very high levels of the O-glucoside of cis-zeatin riboside. The results are a clear indication that O-glucosylation of cis-zeatin is a natural metabolic process in maize. Whether cis-zeatin serves as a precursor to the active trans-isomer or has any other unique function remains to be demonstrated.
150 citations
TL;DR: Kinetin in concentrations of 10(-8) to 10(-4)m, stimulated ethylene production in 3 and 4-day old etiolated seedlings of Alaska pea and Seedlings of other species responded similarly.
Abstract: Kinetin in concentrations of 10 −8 to 10 −4 m, stimulated ethylene production in 3 and 4-day old etiolated seedlings of Alaska pea ( Pisum sativum L. var. Alaska). Seedlings of other species responded similarly. The response to kinetin depended on the age of the seedlings. Kinetin alone did not influence ethylene production in 6-day old stem sections, but it greatly increased the enhancing effect of IAA. Gibberellic acid had no effect on ethylene production by pea seedlings during the first 6 days of growth. Ethylene and gibberellic acid are antagonistic in their effects on growth of the seedlings; ethylene interfered severely with the action of gibberellic acid but did not completely suppress it. The inhibitors cycloheximide, cupferron, and N -ethylmaleimide, caused considerable inhibition of kinetin-induced ethylene production but were much less effective in the endogenous ethylene-forming system.
150 citations