Effect of potassium ion on stomatal opening
Principle: The osmotic system of guard cells can be regulated by potassium ions, and ATP can be formed either by cyclic or acyclic photophosphorylation. ATP continuously supplies the potassium-hydrogen ion exchange pump on the protoplasmic membrane of guard cells for work, supporting guard cells to absorb potassium ions from the surrounding epidermal cells against the difference in ion concentration, reducing the osmotic potential of guard cells, thus making stomata open.
Instruments and drugs: microscope, tweezers, temperature box, microscope slide, microscope cover glass, petri dish, 0.5% potassium nitrate, 0.5% sodium nitrate
Operation steps:
1. With 0.5%KNO3 and 0.5%NaNO3 solution.
2. 0.5%KNO3, 0.5%NaNO3 and 15mL distilled water were placed in three petri dishes, respectively.
3. Tear the epidermis of broad bean leaf and put some into the above 3 petri dishes.
4. The petri dish was placed in a 25℃ temperature box to make the solution temperature reach 25℃.
5. The petri dish was exposed to artificial light for half an hour.
6. Stomatal opening was observed under a microscope.
Post time: Nov-10-2021