Cytokinins have the effect of promoting cotyledon enlargement in radish. Over a range of concentrations (0.05 to 50 pp M for 6-BA agonist), cotyledon weight gain was linearly related to the concentration of
Operation method
Concentration or potency assay of cytokinin-like substances by the radish cotyledon weight gain method
Principle
Cytokinins have the effect of promoting cotyledon enlargement in radish. Over a range of concentrations (0.05 to 50 pp M for 6-BA agonist), cotyledon weight gain was linearly related to concentration.
Materials and Instruments
Radish seeds Move I. Materials and equipment For more product details, please visit Aladdin Scientific website.
Sodium hypochlorite solution
Petri dish, filter paper, tweezers, enameled dish, pipette.
Radish seeds of uniform size
9cm Petri dish, filter paper, tweezers, enameled plate, pipettes: 2 for 5 ml and 1 for 0.5 ml.
Medicines
0.5% sodium hypochlorite solution
100pp M agonist solution: 10.000 M g agonist is dissolved in a small amount of 0.1NHCl (if not, it can be heated in a water bath), and the volume is fixed to 100 ml.
Experimental steps
1. Wash the radish seeds with distilled water after disinfection, then spread them thinly on an enameled plate padded with wet filter paper, cover them with a lid, and germinate them in the dark at 25℃ for about 30 hours. Germination process should be kept enamel disk moist.
2. Remove a smaller cotyledon from each seedling after germination with forceps, the cotyledon must not have hypocotyl. Select 50 cotyledons of uniform size. Weigh every 10 pieces as a group.
3. Take 5 sets of petri dishes with a diameter of 9cm, put a piece of filter paper of the same size as the bottom of the dish and number them. From 1-4 according to the multiplicity of the way were prepared 50, 5, 0.5, 0.05 pp M agonist solution 4.5 ml, No. 5 add distilled water 4.5 ml, 10 pieces of cotyledons in each dish, covered with a lid, and then irradiated with fluorescent lamps at 25 ℃ under the humid conditions of three days of cultivation.
4. Remove the cotyledons, absorb the water on their surface with filter paper, and immediately weigh 10 cotyledons per dish with a 1 in 10,000 balance.
III. Results
Taking the weight gain value of the cotyledons as the vertical coordinate and the logarithm of the agonist concentration as the horizontal coordinate, the relationship curve between the agonist concentration and the weight of the cotyledons was drawn. In the same way, the cytokinin content in the unknown sample can be measured to determine how much agonist is equivalent to the content of agonist.