Obito and Mokuton.

[Kαmi]

I don't think the White Zetsu cells are as potent as having Hashirama's DNA himself. One is artificial and one isn't, it just seems unlikely. Obito likely could have developed high level Mokuton had he worked on in the beginning but I don't think it's safe to assume he can go as far with Madara because of the difference in potency between Madara and Obito when it comes to Hashirama's DNA.

 

[assface3]

Obito's dead.

The closest he's going to get to Mokuton again is the wood his casket will be made out of.