Stud Mount Shower Stalls

[Ryan Watson]

Im working on a stud mount type shower stall with 3 panels. These didnt come with directions and claim there is no calking required. Which i can tell on the corners where the panels come together there is a seal, but what about the bottom where it sits on the tub?

I can tell i need to brace the large panel because its spongy in the center. Will this allow water to go behind the panel and cause mold on the studs or does this evaporate? Do I need to run a seam of glue around the bottom where it sits on the tub? This is not usually my line of work so any help here would be appreciated.