Curling/Cupping Leaves?

I have some plants that have recently been showing cupping leaves/ upward cupping. I never had this problem until about a week ago, when I transplanted them into bigger pots. I was wondering if this could be a nitrogen deficiency? Also the tops of the plants will actually bend over to avoid too much light? This usually only happens in the middle of the day, and when I give them water, it stops. I'm not under/over watering, they should have enough moisture to remain perky without the watering, but they don't. Again, this didn't happen until I transplanted them, I was thinking it was the soil, b/c it's Miracle Grow mix that people claim won't actually feed plants for a long time, which is why I thought it was a nitrogen deficiency? Would it be safe to add chicken droppings? Thanks.

sounds like heat stress

Yeah, it's not unlikely for temps to reach/exceed 85-90 degrees, what can I do to help them? Will this have a long term negative impact on my garden?

water more frequently as well if its possible run a humidifier would help alot get the air exchanging faster

That's the thing, this is an outdoor grow, and they get plenty of air circulation. I guess it's the high temps and low humidity right now. I'll just water more frequently. Have you guys ever seen plants do this b/c of a deficiency of some sort?