More light = plant bubbles?!

I have a 55 gal with co2 injection, with only 60 watts of weak
light (old bulbs)  Today I recieved in the mail a new double strip four 
foot light.  I immediatly got it over the tank with the old lights and watched	
my plants "come to life"  The effect was immediate...they all started to send
a tiny stream of bubbles from various leaves.  I'm not talking just a few bubbles, 
these things were goin' crazy!  Can anyone help me with what exchange is going on
here and what the light triggered to do this?  The books I have do not explain this.
                 Thank  you, Mark Jackson