Hi,
I am new to UE4 and blender. I have created a mesh(Tree) in Blender and i exported into FBX. But my mesh having different look when i imported into UE4. Kindly see the image attached. In blender the transparency of the leafs, but in UE its not transparent. When i analyse the material, In blender the material is transparent, but not in UE. I think the material is not properly imported from FBX.
Please help to fix this issue. Please let me know if more details required.
You cant import materials!! Just textures -> but the UE4 generates a basic material for you when you import it.
To get the right result -> connect the alpha channel of your texture with opacity mask - change the blend mode to " masked" - change the shading model to “two sided foliage” - connect the base colour with the subsurface color 
Great answer, I could solve the problem for Leaf, but there are some problem with trunk. Might be i have to work on the trunk materials. Let me check.
I am not able to upload the image for error because i am getting a “Database Error” while uploading the file.
Make sure that your pic is under 2mb + jpg otherwise just upload the pic to gdriver or dropbox and post the link