Abscisic acid enhances the activity of pectinase and cellulase, causing delamination to occur, leading to shedding. Within a certain concentration range, the shedding rate is proportional to the abscisic acid concentration, and the shedding time is inversely proportional to the abscisic acid concentration.
Operation method
An experiment to determine the activity of abscisic acid by the cotton seedling explant method
Principle
Abscisic acid enhances the activity of pectinase and cellulase, causing delamination to occur, leading to shedding. Within a certain concentration range, the shedding rate is proportional to the abscisic acid concentration, and the shedding time is inversely proportional to the abscisic acid concentration.
Materials and Instruments
Cotton seedlings Move I. Materials and equipment For more product details, please visit Aladdin Scientific website.
Abscisic acid solution
Surgical scissors Single-sided blades Beakers Tweezers Petri dishes Syringes Quartz sand Vermiculite Degreased cotton Agar
Cotton seedlings
Surgical scissors or single-sided blade, beaker, forceps, 10 cm diameter Petri dish, 100 M M 3 syringe, quartz sand or vermiculite, skimmed cotton, agar
Drugs
100 pp M Abscisic acid solution: 20 M g (±)-abscisic acid was dissolved in a small amount of ethanol and fixed to 100 ml with distilled water.
1.5% agar medium: 1.5 parts of agar and 100 parts of distilled water (w/w) were placed in a beaker and heated. When the agar is completely dissolved, pour it into the petri dish while it is still hot, so that the thickness of the agar gel reaches about 5 MM.
Experimental steps
1. Select the full cotton seeds which have been delinted by sulfuric acid, soak them at 28-30℃ for 24 hours, then sow them in moist quartz sand, and cultivate them at 25℃ in a constant temperature box under the light until the first true leaf grows out. The quartz sand should be watered frequently to keep it moist during the incubation period.
2. Remove the explants from the seedlings. The explant is composed of 5 M M true leaf petioles, 5 M M cotyledon petioles and 10 M M hypocotyls. A little bit of skimmed cotton was wrapped on each surface. The hypocotyls were then inserted in agar gel. Ten explants were inserted per dish.
3. 0.05, 0.5, 5, 10 and 20 pp M solutions of abscisic acid were prepared.
4. Petri dishes with cotton explants were divided into six groups, numbered, and each group was treated with one concentration of abscisic acid. The treatment was done by adding 50 M M 3 abscisic acid solution to the cut surface of each petiole with a microsyringe.
5. 24 hours after treatment, the petioles were lightly touched with forceps to see if they were abscised. Thereafter, the petioles were checked with forceps once a day in the morning and evening. Compare the abscission rate of each treatment at the same time and the time taken to reach 80% abscission rate for each treatment.
III. Results 