Nature is amazing in its ability to defend and repair itself when harmed. A new study shows willow trees are able to turn on and off components of their DNA when planted in contaminated soil, strengthening their defenses against heavy metals and other threats. Researchers believe this mechanism could be used to rehabilitate other corners of the Earth soiled by pollution.
Plant biologists at the University of Montreal discovered the interesting trend in trees planted in greenhouses highly contaminated by heavy metals or petroleum byproducts. They compared the molecular responses between trees planted in contaminated vs. non-contaminated soil and found that the former had produced genetic differences indicating a heightened defense system. One example is these trees are significantly less prone to spider mites when compared to the other specimen.
Growing such trees on contaminated soil is called “phytoremediation.” Short-rotation crops can rejuvenate polluted land and willow trees, especially, are low maintenance and produce a quick and high yield of wood for additional profit. It shouldn’t come as a huge shock that nature is adjusting to the way humans are using it, but it is still fascinating to see these adaptations in action.
Furthermore, the study has allowed biologists to explore the concept of a “metaorganism,” or the consideration of all interacting organisms as a single entity. Nicolas Brereton, Ph.D., explains, “By engaging with all diversity of life present, for example, on a single leaf, we can see that these trees can flourish in these challenging environments using natural mechanisms for dealing with chemical stress and that these mechanisms can also help them to defend against herbivorous insects, that the act of tolerance can give them a second, unique advantage.”
The interest piqued in greenhouse research on phytoremediation has encouraged the team to continue their studies on trees grown on actual contaminated land, in hopes to shed more light on plants natural defenses.