Don't Cry for Me, New Zealand-aaaaaa

This from Agence-France Presse: Japanese and New Zealand scientists have figured out how to make a tear-free onion! They thought it just happened when you cut the onion (!), but instead they have discovered an enzyme in the onion's genome that causes the onion to emit an irritant, making the person (or any animal) who destroys the onion tear up. I've always seen it as simply the onion's self-defense mechanism. I figured it had something to do with something being released by the onion, but I had no idea what. I am, after all, no botanist.

There is a catch, of course, when dealing with genetically-modified food. The catch in this case? We have to wait about 10 to 15 years for the tear-free onion to hit the market. Any hidden catches, like those cool weird side effects, are as yet unknown.