What is Pealing?

I could not find a single, concrete definition of the term "pearling."
Please correct any of the following:

"Pearling" refers to the formation of visible O2 bubbles on a plant's
leaves.

The plant normally produces O2 during photosynthesis, although it
"normally" dissolves into the water.

While "pearling", bubbles form because the water has all the dissolved
O2 it can hold. (O2 saturation)

This O2 from the plants is the result of photosynthesis and is not
necessarily an indicator of a plant's health.

O2 saturation and therefore pearling, is dependant on: water
temperature, GH, pH???, KH??? The higher the temp. the more O2 can
dissolve? The higher the dissolved solids (GH) the less O2 can
dissolve? pH and KH are indicators of CO2 and while they effect/are
effected by other values, can determine O2 saturation point.

Sorry, I guess I have a more scientific mind.... I like to see things
spelled out. Besides, hopefully this will help someone else that wants
a definition of pearling.