Hi ! I was searching on Z2 forums and seems like they have managed to Root Z2 with kingroot method on locked bootloader. Its not working on Z1 currently but with some modifications it just might. Its almost the same rom still. I have no experience but someone might just get this working on Z1 too ! Just wanted to let you guys know ! Good luck o/
Here is the thread: http://forum.xda-developers.com/xper.../root-t3108230