Trees impregnated with gold might someday line city streets
bldgblog.blogspot.com
bldgblog.blogspot.com
The thought made me a bit sad since the idea of magical glowing trees lining our streets was so beatiful. Hm. I guess that at least means I'm not as cynic as I thought, which is good, I guess. :)
To me this seems more like a proof of concept article, yet, it opens an area of research which may in fact succeed after some time. And there are a so many easy ways to make something like this hard to steal- I won't go into details because this is not the important here.
I would imagine that this would be much less efficient than normal lighting and constant exposure to UV probably wouldn't do the trees or people any good at all.
At that point, you might as well just engineer a luciferase system (three well known ones: renilla, firefly, bacterial) that emits blue light and throw in a chain of flourescent proteins (gfp, rfp) that shunts an appropriate amount of color down the chain. Then, you could use a promoter system to force expression only on the bottom side of the leaf, and only during the nighttime.
Very possible within the realm of current science, the only question is how well would the tree tolerate it. And considering it takes years for a tree to get that big, that's a long time to wait to find out.