(...)
> I believe there are Nepethes associated bacteria that exhibit chitinase
> activity. Since plants don't have chitin in their cell walls (AFAIK)
> this would only degrade the insect exoskeletons and not the plants cell
> walls (made mostly of cellulose).
Chitin is a very stable polysaccharide (like cellulose) not easily
attacked by the usual hydrolases. Under the conditions of chitinase
activity, it is somewhat tricky to prevent cellulose degradation.
There are of course possibilities to protect the plant surface by
thick cuticulae etc. Chitinases are (AFAIK) not common plant enzymes
(if you do not consider the bacteria in _Nepenthes_ to be plants).
Kind regards
Jan