Silly question time!

Hi, I planted some runner beans in toilet rolls last week . I've just noticed that a single shoot coming from the bottom of a couple of the rolls. Are these the plants going the wrong way? Should I turn over the rolls?
As I'm on here I might as well ask another question. I put some celery seedlings in a cold frame and some of these have gone white around the edge of the leaves and shriveled a little. I take it is because they are either too dry or too hot. Which one please. I made the cold frame out of polycarbonate so may be it is too hot?

It is the root - a plant knows which way to grow!

I think the white around the edges of the celery is more likely to be from being too hot, rather than too cold, when the sun comes out a "cold" frame or greenhouse gets very hot, unless it's ventilated.

Thank you for your quick replies. Yes, I  guess a plant will know where "up " is. As for the coldframe, the temperatures haven't been that cold at night so I guess it's the heat. I will now ventilate if the sun should happen to come out!