This hand was played in a live 5/10 PLO game recently. MP is a decent TAG. HJ is a mediocre loose semi-aggressive player. CO is a reg who is a little tighter and more passive than most.

Folded to MP (1k) raises to 35
HJ call (1.3k)
CO call (3.2k)
Button call (2k)
SB fold
Hero BB call (1.2k) with Asts9c4d

Pot is 180
Flop Ac9h7c
Checks to CO who bets 140
Button folds
Hero calls
Everyone else folds

Pot is 460
Turn 5h
Hero checks
CO bets 340
Hero?

1. Is check calling a reasonable line on the flop? If not, is there another reasonable play or should I just ck/f?
2. The turn card isn't awful, but stacking off with an SPR of 2 still feels pretty gross. Thoughts on how to play the turn?

Thanks