Luminosity. The White Road Chronicles, #2

Alburnium is at war. Eighteen-year-old Alyra's joy of being reunited with her family fades when Prince Issah sends her beloved friends away on quests across the kingdom. Allies must be gathered to stand against the dark ruler, Lord Darnel. The reclusive dragons happen to be necessary allies. Alyra's friendship with the young drake, Crystal, offers a slim hope of being heard by them instead of being burned. Alyra must attempt her own quest and travel to Drakensburg with her resentful brother, Ethan, a Messenger, who doesn't trust her, a prankster Okbold intent on honoring his debt to her, and a unseen Guardian Instructor, who must teach her how to use the Illuminate's gift before they reach the dragons' hold. Ethan has the words to persuade the dragons.
Alyra carries the red fruit of the White Tree to present as a peace offering. Until she finds Tarek, beaten and near death. She must choose between using the fruit to save the man she loves, or the kingdom she serves.