For those not in the know, Gamora is one of two adoptive daughters of the Titan Thanos - the guy during the mid-credit sequence of Joss Whedon's The Avengers (spoilers if you're one of the three people who didn't know that yet).
Our own Luke Owen wrote in his Who Are The Guardians of the Galaxy piece last year that, "After Gamora was attacked and raped by a group of thugs as a teenager, Thanos gave her treatments that improved her speed and strength which, coupled with her already incredible martial art skills, makes her a deadly woman. She has been known to use weaponry in the past, but her biggest skill lies in her fighting."
Already cast in Guardians of the Galaxy are Parks and Recreation's Chris Pratt as Star-Lord and former WWE champion Dave Bautista as Drax the Destroyer. The roster will be completed by Groot and Rocket Raccoon who have yet to be cast.
In other Guardians of the Galaxy news, Latino Review are claiming that Basil Sandhill aka The Controller will be the main henchmen of Thanos in the movie. They have also made the assumption (which we imagine will be correct) that Thanos will indeed be the main villain of the film.
However nothing is confirmed here so best take this news with a pinch of salt.
Guardians of the Galaxy will be the last Phase Two movie before The Avengers 2 and is set for release on August 1st 2014.