Fluorescent plants

This is what I worked on this afternoon! These are the roots of Arabidopsis plants, progeny of the ones that showed resistance on the kanamycin plates from a few weeks ago. I took one picture with regular white light (on the left) and then took another picture with fancy light and a filter (on the right). The top two pictures are of non-fluorescing plants, to make sure there is no background fluorescence. If you tilt the computer screen just right, and are in a dark room, you can just see the fluorescence in that one. The bottom two pictures are from my transgenic plants, and as you can see the fluorescence is gangbusters in these guys. The exposures are the same for both the fluorescence images.

I have been working on making these plants for a year and a half, longer if you count the time I spent making the DNA to insert into the plants. Now I am absolutely certain I will graduate!

The red color is because these plants are making a protein called tdTomato, which is a red fluorescent protein. When light of the right wavelength (in this case green) hits the protein, the protein then emits light itself of a longer wavelength (in this case red). In plant leaves a red fluorescent protein isn't always the best thing to use, because chlorophyll, when exposed to green light, also emits red light, so it isn't clear whether the red you see is from the chlorophyll or from your protein. However, in the roots, there is no chlorophyll, so that is no longer an issue.

This particular batch of plants is producing a hybrid protein, so the tdTomato protein has an extra bit attached to it, which is what I am interested in investigating. This extra bit should be able to become covalently attached to the cell wall, so it will cause some interesting physiological effects that I will be able to measure, aside from just looking at the glowing roots.

I love looking at my plants in the microscope. Since they are alive, they are still making tdTomato while they are under the microscope, and I can actually see little bundles of red moving around inside the cell. It is breathtaking. It also means it takes forever for me to get all my pictures, because I spend so much time lollygagging! (I took a lot more pictures than those four up there, for documentation purposes.)

I got to show Pat these plants in the microscope today, and she gave me a high five. Whoop!