UV Reactive Plants

[foxgrrl]

I recently got a UV LED flashlight, and now I play the What-here-is-florescent-game wherever I go. So, chlorophyll is not, but dust and mold are - mold fluoresces bright yellow (I'm having a bit of a problem with blight at the moment). But one of the stranger things I noticed, was that my tomato seedlings fluoresced red. And on the larger tomato plants, the undersides of the leaves and the newly growing ones also fluoresced red. And on the green onions, the bottom part of the stalks, that area glows red too. So, I'm guessing that it's areas of the plant which have little chlorophyll where this is occurring - or that the chlorophyll is not blocking the light. Most of the other plants I have examined don't fluoresce red. So does anybody know specifically what is fluorescing? I speculate that it might be another pigment like anthocyanin, but that's totally a wild guess.

Update: Oh I should also mention that I have not yet found any flowers which fluoresce. So maybe it's not anthocyanin - if I had an apple I could test this.

Comments

[hasufin.livejournal.com]

Try potatoes and see if those get results as well? It might be something endemic to the nightshade family, though I guess that wouldn't explain the onions.

[mikeys.livejournal.com]

A good UV bandpass filter really helps cut out the blue so you can see florescence better. Check out the conservatory flower garden at night :)

[anaisdjuna.livejournal.com]

Nice to see your light fluoresce here after so long.

*gentle smile*

[mayamaia.livejournal.com]

Tomatoes are mildly poisonous in every part except the fruit... don't understand the green onions though.

[dragonzuela.livejournal.com]

Chlorophyll absorbs red light, so it make sense that you wouldn't see the fluorescence where there is a lot of chlorophyll. I don't know what the compound is though... some of my other guesses were phytochromes and cryptochromes although I haven't found anything about them being fluorescent.

[ivy]

Chlorophyll does block to some degree, I believe. Could be one of the amines -- feruloyltyramine and p-coumaroyltyramine are mentioned as fluorescing here -- you could test that by wounding, but that's not really a nice thing to do to the plants. There's a discussion of light levels, chlorophyll presence, and fluorescing in tomato leaves here, though that's lower levels than you might be seeing with the naked eye.