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Hormone |
Cytokinin (CK) Cytokinin is synthesized in the greatest amounts in root tips - A Wikimedia Commons Image |
Chemical Structure |
Zeatin |
Speculative Overall Role |
Root nutrition other than water abundance signal |
Growth Direction Tendancies | Broadening or widening |
What is Cytokinin's speculative |
Gibberellin and Brassinosteroid |
If overall speculative role is |
Well fertilized plants should have high CK levels, plants living in poor soils should have low levels. CK should be mostly made in meristematic cells and much less so as cells mature. CK should be made when a cell has more than enough essential minerals to support both it any cell dependent on it for mineral acquisition. Thus CK is always an indication that growth amounts of minerals are being procured by the plant and if conditions warrant, that the plant has enough minerals to grow at least in the specific cell where the CK is. (Root cells are responsible for acquiring minerals for both it and similar size cells in the root. Conversely a shoot cell is only responsible to itself for it own mineral nutrition levels). |
If overall speculative role is true, what |
Should induce Strigolactones, because CK up regulates various processes limited by minerals. Exogenously applying CK leads the plant to falsely believe that it has high levels of minerals, thus engaging all sorts of reactions that use or are normally limited by mineral levels, thus further depleting what may simply be a homeostatic level of the existing fertilizers and moving this level into the deficiency range. |
If overall speculative role is true, what |
Should induces new shoot growth, just like SA. Especially if SA is also present, CK should inhibit root growth because high SA and CK levels are an indication of at least a short term lack of need to expand the roots. |
If overall speculative role is true, |
CK should cause excess minerals to be stored in vacuoles, storage proteins and tubers for less propitious times. |
If overall speculative role is true, |
CK may be expected to travel in the direction of the shoots, away from the roots and particularly away from root meristems. Regions of a cell or tissue or plant part that contains high CK, may particularly attract fertilizer type minerals and transport of important minerals may follow active or passive CK transport up a plant in the xylem or other tissue. |
If overall speculative role is true, how should |
Should attract all nutrients and abundance hormones/signals to a cell and repel deficiency hormones/signals. |
If overall speculative role is true, how |
Should induce root apical dominance along with SA, however the possibility exists for two dominant apices if one is particularly good at fertilizer absorption (in good soil) and one good at water harvesting (in the moist part of the soil). CK may break shoot apical dominances under conditions of low JA and IAA. |
If overall speculative role is true, how |
Along with IAA and JA and Salicylic acid, CK should be necessary for cell division. If there are some plant callus lines that will divide with only Auxin and Cytokinin present, it is because these cell lines are mutants that produce SA and JA natively. Alternatively these latter two hormones are unknowingly being included with other nutrients/vitamins that are also added to calluses to get them to divide. |
If overall speculative role is true, how |
Should protect plant tissue from senescence, particularly shoot tissue. |
If overall speculative role is true, |
Cytokinin has been found to broaden plant parts, including leaves and stems. Should complementit's analogue deficiency signal Strigolactones effect on plant growth. Strigolactones should lengthen plant cells and tissues. |
Proven Synthesis and Transport |
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Proven Effects |
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