This article or section is in need of attention from an expert on the subject. Please help recruit one or improve this article yourself. See the talk page for details. Please consider using {{Expert-subject}} to associate this request with a WikiProject

Zeatin is named after the genera of corn, "Zea" as it was first discovered in corn.

Cytokinins (CK) are a class of plant growth substances (plant hormones) active in promoting cell division, and are also involved in cell growth, differentiation, and other physiological processes. Their effects were first discovered through the use of coconut milk in the 1940s by a scientist at the University of Wisconsin-Madison named Folke Skoog. Image File history File links Information_icon. ... Image File history File links ZeatinII.png Zeatin the Plant Hormone made with the freeware, Chemsketch, version 8. ... Image File history File links ZeatinII.png Zeatin the Plant Hormone made with the freeware, Chemsketch, version 8. ... Plant hormones (or plant growth regulators, or PGRs) are internally secreted chemicals in plants that are used for regulating their growth. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta—liverworts Anthocerotophyta—hornworts Bryophyta—mosses Vascular plants (tracheophytes) †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls Lycopodiophyta—clubmosses †Trimerophytophyta—trimerophytes Pteridophyta—ferns and horsetails Seed plants (spermatophytes) †Pteridospermatophyta—seed ferns Pinophyta—conifers Cycadophyta—cycads Ginkgophyta—ginkgo Gnetophyta—gnetae Magnoliophyta—flowering plants... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... This does not adequately cite its references or sources. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. POOP Cells in culture, stained for keratin (red) and DNA (green). ... Embryonic stem cells differentiate into cells in various body organs. ... Leonardo da Vincis Vitruvian Man, an important early achievement in the study of physiology. ...

There are two kinds of cytokinins:

• Adenin cytokinins

Examples: kinetin, zeatin, benzyl adenine ( same as 6-Benzylaminopurine). The DNA base adenine is a structural analogue of cytokinins and have low cytokinin bioactivity. Kinetin is a chemical plant hormone that promotes cell division. ... Zeatin is a cytokinin (Not to be confused with cytokine), a plant hormone derived from the purine, adenine. ... Chemical structure of 6-Benzylaminopurine 6-Benzylaminopurine, aka Benzyl adenine or BAP is the first generation synthetic cytokinin which elicits plant growth and development responses setting blossoms and stimulating fruit richness by stimulating cell division. ... Chemical structure of 6-Benzylaminopurine 6-Benzylaminopurine, aka Benzyl adenine is the first generation synthetic cytokinin which elicits plant growth and development responses setting blossoms and stimulating fruit richness by stimulating cell division. ... The structure of part of a DNA double helix Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the development and function of living organisms. ... This article or section does not adequately cite its references or sources. ...

• Phenylurea cytokinins

Example: N, N'-diphenylurea

Although their chemical compositions differ, there is a structural correlation between adenine cytokinins and urea cytokinin, and both show similar biological activities.

Location, characteristics and occasions for synthesis induction

• Synthesized in root and shoot meristematic tissue
• Synthesized in mature root cells – small amount
• Rapidly transported in xylem stream at the plant level
• Transported by purine transporters at the cell level
• Reduced in plants suffering from drought
• Peaks during the day
• Released by meristematic cells when they have enough minerals and water to support both themselves and any dependent cells
• Released by all cells when they are experiencing conditions that would normally cause a shoot meristematic cell to produce CK
• Directly or indirectly induced by high levels of GA/BA

Primary and secondary roots in a cotton plant In vascular plants, the root is that organ of a plant body that typically lies below the surface of the soil (compare with stem). ... In botany, the shoot is one of two primary sections of a plant; the other is the root. ... A meristem is a tissue in plants consisting of unspecialized, youthful cells (meristematic cells) and found in zones of the plant where growth can take place - the roots and shoots. ... In vascular plants, xylem is one of the two types of transport tissue in plants, phloem being the other one. ... Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ... A drought is a period of time when there is not enough water to support agricultural, urban, human, or environmental water needs. ... Minerals are natural compounds formed through geological processes. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ...

Effects

Cytokinins generally promote shoot development and inhibit root development, although they are necessary for cell division in both shoot and root apical meristems.

• Promotes chlorophyll production and leaf unrolling
• Promotes photosynthesis
• Stimulates cell broadening
• Promotes shoot formation
• Promotes the unloading of sugar from phloem
• Causes the outgrowth of secondary shoot buds – breaks shoot apical dominance/lateral bud development
• Delays leaf senescence
• Stimulates cell division with auxin
• Participates in morphogenesis
• Induces creation of xylem and phloem
• Inhibits C4 Photosynthesis
• Stimulates the rate of metabolism of cells in the shoot (that are not at their peak metabolism rates) in response to an increase in the levels minerals and water (speculative)
• Inhibits root bud outgrowth in a similar apically dominant way as Auxin inhibits shoot bud outgrowth (speculative)
• Directly induces GA/BA at high levels (speculative)
• Stimulates an increase in flow of sugar and oxygen toward the site of synethesis, by promoting the use of stored nutrients of the ones mentioned, an increase of active transport of the nutrients, a change in shoot growth from the GA induce lengthening to broadening and the induction of new shoot growth (speculative)

Chlorophyll gives leaves their green color Space-filling model of the chlorophyll molecule Chlorophyll is a green photosynthetic pigment found in most plants, algae, and cyanobacteria. ... “Foliage” redirects here. ... The leaf is the primary site of photosynthesis in plants. ... IAA appears to be the most active Auxin in plant growth. ... Morphogenesis is also the name of a band. ... In vascular plants, xylem is one of the two types of transport tissue in plants, phloem being the other one. ... In vascular plants, phloem is the living tissue that carries organic nutrients, particularly sucrose, a sugar, to all parts of the plant where needed. ... A few of the metabolic pathways in a cell. ...

Natural Sources

• Ascophyllum nodosum seaweed

Binomial name Ascophyllum nodosum (L.) Le Jolis Knotted wrack (Ascophyllum nodosum (Linnaeus) Le Jolis) is a large, common, brown, edible seaweed of the northern Atlantic Ocean. ...

External link

• Plant Physiology:Cytokinin
• Thidiazuron (plant growth regulator)
• Zeatin (plant growth regulator)
• Speculations Towards a General Plant Hormone Theory