Science Questions

How do plants protect themselves from UV damage? If humans can get skin cancer why don't plants? Chris Burgess

Chris - There was a study that was done on edelweiss, not just the song in the Sound of Music. This is a plant that grows high up in the alps. Because it's growing at altitude it's exposed to a lot of solar radiation and a lot of ultraviolet so how does this fend off? Scientists recently published a paper in which they looked at the surface of the leaves of edelweiss and they found these tine hairs. If you zoom in on the hairs the hairs are made of even tinier filaments which are about 100nm across. 100nm is roughly the wavelength of ultraviolet light. These hairs interfere with or interrupt the passage of the ultraviolet light, stopping it getting onto the leaf surface. Instead they channel the ultraviolet into some water in the middle of the hair and this soaks up the UV and protects that plant.

Helen - Could we make this into anything we could use? The new generation of sun creams perhaps?

Chris - That's not such a silly thing to say because yes, people are saying we might be able to make nano technology sun cream. Sun cream uses titanium dioxide that you just spread on the skin. They're saying if we made edelweiss extract you could rub this on the skin and the same trick might work to fend of the UV rays.

October 2008