Growth hormone promotes the elongation of the germinal sheath and stem and the development of the fruit, as well as the formation of roots. Within a certain concentration range, the number of roots formed increases proportionally to the concentration, while too high a concentration is inhibitory. The potency of a similar growth hormone or the concentration of endogenous growth hormone in an extract can be measured when a standard growth hormone solution is used for comparison.
Operation method
Concentration or potency experiments for the determination of growth hormone analogs by the mung bean root formation method
Principle
Growth hormone promotes the elongation of the germinal sheath and stem and the development of the fruit, as well as the formation of roots. Within a certain concentration range, the number of roots formed increases proportionally to the concentration, while too high a concentration is inhibitory. The potency of a similar growth hormone or the concentration of endogenous growth hormone in an extract can be measured when a standard growth hormone solution is used for comparison.
Materials and Instruments
Mung bean seeds Move I. Materials and equipment Figure 5 Mung bean cuts for growth hormone bioassay (4) Plotting the standard curve: Use the logarithm of the concentration of the growth hormone solution as the horizontal coordinate, and the ratio of the number of roots in the growth hormone solution and distilled water (L/L) as the vertical coordinate. The standard curve was plotted using the logarithm of the concentration of growth hormone solution as the vertical coordinate. For more product details, please visit Aladdin Scientific website.
IAA solution
Incubator Enameled dish Beaker Blade Graduated pipette Petri dish Tweezers Quartz sand
Mung bean seeds
Incubation chamber (700-750 meter candles), warming oven, enameled plates, beakers, blades, graduated pipettes, petri dishes, forceps, quartz sand.
50pp M IAA solution: weigh 5 mg of IAA, dissolve it in water (slightly heated), and make up a volume to scale in a 100 ml volumetric flask. Shake well and store in refrigerator for use.
Experimental Procedure
(1) Cultivation of mung bean seedlings: Soak mung bean seeds in hot water of about 80 degrees Celsius, and when the water cools down to room temperature, continue to soak for two hours so that the seeds are fully absorbed. Then the seeds are placed in a petri dish padded with moist filter paper and allowed to germinate in a constant temperature box at 25 degrees Celsius, and after 24 hours, the neatly germinated mung bean seedlings are selected and sown in moist quartz sand and placed at about 25 degrees Celsius, with a light of 700-750 meter candles for cultivation to 7-10 days when the mung bean seedlings have a pair of unfolded By 7-10 days, the mung bean seedling has a pair of unfolded true leaves and three compound leaf buds, and is ready to be prepared for cutting for testing.
(2) Preparation of seedling cut sections: Choose neatly grown mung bean seedlings, use a razor blade to cut off the root system from 3 centimeters below the cotyledonary node of the seedling, if the cotyledonary leaves are not shed, then the cotyledonary leaves will also be removed. At this time, the cut section with 3 cm long hypocotyl, the first pair of true and compound leaves, buds (see Figure 9). The prepared cuts were soaked in water before the experiment to avoid air-drying of the cuts.
(3) Six 50 ml beakers were taken and numbered with a glass pencil. 50 ml of 50 pp M IAA solution was poured into the first beaker and 5 ml was pipetted out and transferred into the second beaker. 45 ml of distilled water was added to the second beaker and stirred well with a glass rod to make a 5 pp M solution, and so on, releasing it step by step until it was formulated as 005 pp M indoleacetic acid in the fifth beaker and 5 cm 3 was pipetted from it and discarded, and then the second beaker was filled with 45 ml of distilled water. Add 45 ml of distilled water to the No. 6 cup as a control, and mark the height of the liquid level on the outside wall of each cup, and the degree of solution in each cup is as follows: Insert 5 or 10 sections of prepared mung bean seedlings into each beaker, and immerse the cotyledonary nodes below the liquid level. Distilled water was added every 24 hours to maintain the original solution volume. after 7 days, the number of roots grown by each cut section was counted. It can be seen that the number of roots increased with a range of growth hormone concentrations.
Beaker number 123456
IAA (pp M ) 5050.50.050.0050.00
1. compound leaf 2. true leaf 3. epiblast 4. hypocotyl
(5) The determination of the concentration or potency of the last known samples: If there is the last known concentration of growth hormone extract or the last known potency of similar growth hormone solution, need to be measured, can be based on the above method to find the L / L, and then compared with the standard curve, you can find the concentration or potency.