Science Buddies: "Ask an Expert"

Hi, I am now in 8th grade and doing another science fair project. If you've seen my previous post, I did a project on the effect of uv radiation on plant growth. This time, I decided to do a project continuing that except measuring resistance. So, do you guys think that by feeding plants zinc oxide, it'll increase their resistance to uv-b radiation. I think what I would do is expose the plants to uv radiation but except this time tweak it to expose them to radiation even further. This time, I will mix zinc oxide into the water i feed some of the plants it and in the end of the project, see if the features of the radiated plants without zinc oxide are worse than those with zinc oxide. May you guys help me see if this project would even work. Thanks!

Hi,

Welcome back to Scibuddies!

I remember all our previous posts about your project with the lettuce plants and the ‘UVB’ lamp. Did you find a lamp that emits only UVB?

With regard to using zinc oxide, ZnO, to protect plants from UV, you cannot ‘feed’ it to plants in water because ZnO is not soluble in water. ZnO sunblock is applied to a person’s skin before they go out in the sun and protects them by preventing the UV from penetrating the skin.

What is your hypothesis?

There might be some chemical that you could spray onto your plants that would absorb UVB radiation and prevent the photomorphogenesis that you seemed to see in your previous project. If you really want to test sunscreens for plants, I would do some more research and see what chemicals might work without harming the leaves.

Hopefully the other experts will contribute their ideas about how to make this a good project and what experiments could be done.

Good luck!

Sybee

Hi,

Thank you for your question. This lab is commonly executed with photocatalyst nanoparticles that are created with ZnO powder disperssed in Milli-Q water through ultrasonication, which is a fancy word for the act of applying sound energy to agitate particles. However, the creation of these nanoparticles is often done professionally at a lab.

What you can possible do is use Lutein, commonly used to protect eyes against UV radiation. What protect plants from radiation are Xanthophylls, which capture wavelengths of sunlight not absorbed by chlorophylls, and thereby increasing overall absorptance of the visible spectrum of sunlight. This helps to prevent damage within the chlorplast. It is possible that a mixture of lutein (a type of xanthophyll) powder and water can be used to protect your plant from UV radiation. You may also try to use ZnO in the form of a powder and create a solution to water your plant with. Let me know what works for you.

oh, thanks brianali123. I could possibly try both to see which works better when protecting the plants. But, do you think adding ZnO powder or Lutein will be toxic if we consume it. Because this project will be quite pointless if it just makes the food poisonous for us to eat. Pleas let me know. Thanks!

Lutein is a compound found in plants, and this is a study that showed no toxic effects of lutein: http://www.ncbi.nlm.nih.gov/pubmed/21872637. The MSDS on Zinc Oxide says it has low oral toxicity because it is not readily absorbed when it is ingested, so I think that would also be safe to use on plants.

Hope that helped answer your question! Let us know if you have any more questions on your project.

Oh thank you. So, do you know any techniques that could help measure how effective the lutein mixture fed to the plants is?

I was thinking maybe you could measure plant growth to see how healthy they are. Science buddies has a page about all different aspects of plant growth you can measure. Here is a link:

https://www.sciencebuddies.org/science- ... owth.shtml

Do you have any other ideas?