Hello.
sometimes water just produces bubbles even without any plant in it! If the water is under pressure in the water pipes before you open the tap, then the water has lots of air dissolved in it and this will come out of solution when you leave it to stand. If you boil water, it will get rid of the air.
The gas bubbles generated during photosynthesis by aquatic plants produce distinctive sound pulses when leaving the plants. In photosynthesis of submerse water plants Oxygen emission occurs in form of bubbles which are released from the stomata or small openings caused by injuries.
Have a nice day
