Unfortunately, Star - Lord uses this opportunity to gloat, and it reveals an ugly truth: that Thanos killed Gamora in exchange for the Soul Stone. (cinemablend.com)
A lot of people bite the dust — heh, dust — in Infinity War, but perhaps the most emotional demise belonged to Gamora, who tried to kill her adoptive father Thanos, then herself, before he sacrificed her in exchange for the Soul Stone. (ew.com)