Alot of teachers to get you started -
In my experience as a bassist who enjoys both playing fusion and who continues to take lessons as a professional - 'Fusion' and Jazz' - Fundamental music ideas. Theory and ideas/approach to progressions, fingerings, sales, arpeggios, chordal studies etc. It's music after all. There is very little that is different between standard jazz studies although 'fusion' can cover alot of ground between rock and jazz. And in truth, even that is an incomplete idea. The crossover is massive and the genre is massive.
This may sound super obvious and forgive me if this is your practice already, but listening to fusion bass players and fusion artists regularly/daily/consistently is going to be the biggest advantage in applying anything you are taught. A great deal of fusion/jazz bassists have played with the same artists. It's worth noting - being a big fan of the genre and listening is the fastest way to improve.
One example to get you started is one of my favorite guitar players/writers/session men Lee Ritenour
Bassists playing with Lee: I likley missed a few.
Anthony Jackson
Marcus Miller
Abraham Laboriel
Chuck Rainey
Alphonso Johnson
Jimmy Haslip
Jimmy Johnson
Mike Porcaro
Bill Dickenson
David Hungate
Melvin Davis
Lee Sklar
Tim Landers
Louis Johnson
John Pattitucci
Nathan East
That is just one artist.
Tetsuo Sakurai (Casiopea) is my personal favorite but as you delve into the genre you will uncover a massive gold mine of unsung brilliant and inspiring bassists to keep you inspired and learning.
All the best and best of luck, I always love hearing people getting deeper in the genre.