Is it possible to have a Noise input in a shader than could modify a vertex group attribute for generating particles in that place??
The short answer is: no. There are workarounds, but they are tedious and depending on what you are trying to achieve it might not work. The most direct approach would be to use the texture, or a grayscale copy of it in the particle settings. This won't work for procedural textures atm, though. So even more tedious: You could bake them, but that's a story for another thread.