I have ticked "Use Alpha" with "Straight" option in texture and "Transparency" in material. However in render mode & material mode transparency is always white.
In texture mode, transparency works with "Multitexture" renderer, but with "GLSL" transparency doesn't work neither in texture mode.
I am using blender renderer.
Here is my blend file: https://www.dropbox.com/s/mlcn4zrkr7n8j1t/tree.blend?dl=0
The problem is the transparency with "leaves" object and its texture