Roth seedling browned leaf

[Ernesto]

My roth seedling’s oldest leaf browned, which is concerning to me since it’s a young plant. Is this normal or is there something wrong? I also attached photos of what I think is mesophyll collapse, but I welcome ya’ll’s opinions. I really want this guy to succeed.

 

[Ozpaph]

1. just a dying leaf. pull it off when it dries.
2. mesophyll collapse.

otherwise fine.