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Auxins: Auxins are generally used in plant cell culture at a concentration range of 0.01-10.0 mg/L. When added in appropriate concentrations they may regulate cell elongation (if the concentration becomes higher, elongation of root and shoot is inhibited due to ethylen production), tissue swelling, cell division, formation of adventitious roots, inhibition of adventitious and axillary shoot formation, callus initiation and growth, and induction of embryogenesis.

Cytokinins: Cytokinins are generally used in plant cell culture at a concentration range of 0.1-10.0 mg/L. When added in appropriate concentrations they may regulate cell division, stimulate auxiliary and adventitious shoot proliferation, regulate differentiation, inhibit root formation, activate RNA synthesis, and stimulate protein and enzyme activity. Apart from DNA replication rate, cytokinins increase the general rate of RNA and protein synthesis too. They reduce senescence and stimulate the dark- germination of light-dependent seeds.

Gibberellins: Gibberellins are generally used to promote flowering, break dormancy of seeds, buds, corms, and bulbs, and causes stem elongation. There are over 90 forms of gibberellins, but GA₃ is the most commonly used form. Compounds like paclobutrazol and ancymidol inhibit the synthesis of gibberellins. For certain certain long-day plants or plants requiring vernalization addition of GA₃, causes their flowerig, even without the other necessary extern signals, stimulating previous elongation of the stem axis. In plants germinating only in light was it shown that gibberellins are also able to substitute P_FR. Gibberellins (like the best-studied GA₃) control the formation and secretion of hydrolases in grains.

Abscisic Acid: Abscisic Acid (ABA) plays a role in dormancy development in embryos, buds and bulbs, and in leaf abscission. When used in tissue culture, ABA inhibits the growth of shoots and the germination of embryos. Moreover, regulating effect of abscisic acid on the water balance was observed. As soon as cell turgor decreases raises the concentration of ABA. It induces the stomata to close thus inhibiting further loss of water. Fluridone may inhibit ABA synthesis.

Ethylene: Ethylene promotes maturation and abscission of fruits. In addition, ethylene regulates senescence and fading of flowers and abscission of petals and leaves. In most cases, flower formation is inhibited by ethylene. Ethylene has evolved as the central regulator of cell death programs in plants. AVG (aminoethoxyvinylglycine) und AOA (aminooxy-acetic acid) are inhibitors of ethylene biosynthesis.

Polyamines: Polyamines are compounds that occur in high levels within plants and are used in tissue culture media at concentrations of 10-1000 mM. Polyamines may enhance regeneration of roots, shoots and embryos, delay or prevent senescence, and regulate flowering.

Synthetic Growth hormones and Growth Inhibitors: Either synthetic components simulating the effects of phytohormones are used, or inhibitors of biosynthesis of phytohormones are taken to generate a lack of hormones in the cells. In agriculture and forestry herbicides are used to stop the growth of unwanted plants, like of yield-reducing weeds.