was it also moved to intense sunlight at same time? if so, it's more likely the sun's effect.
you don't need a humidity dome for seedlings unless you are in an arid climate or maybe if really hot.
this is a bit bigger than a "seedling." Assuming it can handle the light, it should be ready for primetime nutes and all... if new to the sun, you need to slowly introduce it to that sort of intensity.. shade it, slowly add more light.