Submitted by iKeyvier t3_10mudla in askscience

Considering they need sun light to live, it would make sense to assume they are also exceptionally subject to UV light and subsequently to cancer. Skimming through some papers that were only marginally relevant to this, it appears that plants do indeed show reduced incidence of cancer compared to what would be normally expected in an organism that has no way to prevent cancer. So, are their mechanisms the same as ours? Is there any mechanism exclusive to plants? In which case, could we technically implement it in animals as well or understand cancer better?

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LittleCreepy_ t1_j65ledq wrote

Plants have an exclusive cancer prevention in the rigidity of their bodys. The solid cellwalls and hydrostatic pressure prevent a lot of deseases from moving inside of them. Cancer too is inhibited by this, and is forced to grow localy. As you might guess, that isnt exactly possible for use in animals.

Plants can in fact develop cancer. The bulbous growths near the ground are often exactly that. They can among other things be caused by the bacterium agrobacterium tumefaciens. We use them for genetic editing of plants.

When we want to grow a lot of similar plants, like orchids for example, we start with a single cell and, with different hormons, go from meristemic cultures to callus cultures. Those are basically cancerballs.

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DaylightsStories t1_j65o5mq wrote

There are several factors that go into this. They produce sun screens for themselves to protect against the sun, they produce antioxidants to try to mitigate DNA damage, and they have powerful DNA repair mechanisms compared to animals.

All of this pales, however, in the face of their anatomical resilience. Plant cells are immobile and no part of their body is irreplaceable, except the primary stem and even that is only irreplaceable in some species. The parts of a plant that are most exposed are typically leaves or photosynthetic stems, and in most cases these are only retained for a few months to a few years before they fall off. In the event that plants do have uncontrolled cell division, it cannot metastasize and they will probably be rid of it soon. If it's on the main trunk, it still probably isn't stopping anything essential.

So they do have more powerful mechanisms for DNA repair, but this is enabled because if they have a catastrophic error it's not actually catastrophic while in animals a catastrophic repair mistake means death. Animal cells will often die if their DNA is notably damaged rather than risk becoming cancerous while plant cells are less likely to do that and so they benefit from being good at fixing things.

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DaylightsStories t1_j6877oe wrote

I believe so yes. There is nothing that will carry cells around. Pardon me if I say anything inaccurate about the spread of cancer. My degree is in plants, not animals and certainly not humans so everything I know about that is in relation to mechanisms that plants have. All the animal knowledge I have is sparse and primarily ecological.

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kytosol t1_j689dp2 wrote

Plants get lots of tumors. If you look at the big knots or bumps on a tree they are usually tumors. The difference with plants and animals is that in plants any cancerous uncontrolled cell growths are usually immobile and can't spread, and therefore don't have much of an impact on the life or critical function of a plant.

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