How to get old without aging
I stole this title from a cool article I found today, unfortunately it's not about a super old Japanese, Greek or Italian individual, the subject in question doesn't even belong to the animal kingdom, but it's about plants. Talking about kingdoms I know plants do not usually fall into the realm of things we consider cool. From my previous experience on Steemit I noticed that all my plant posts were ignored by most users but hopefully I will find someone that shares my same interests. I know plants are not as cool as the Jesus Christ lizard that walks on water or like chickens that can play piano (apparently it's a thing) but plants have been around for a bit longer than us on our planet and during their existence they have accumulated a bunch of cool tricks in their evolutionary arsenal.
For instance, while we are able to move and seek more “friendly” habitats, plants have to cope with the environment they are in by adapting. In plants, like in mammals, oxygen is an indispensable substrate that fuels biochemical reactions. But, despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, there are steep oxygen gradients within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability (e.g. roots cells can survive immersed in water for days when it rains). Nonetheless, plants can tune their metabolism to cope with energy crises induced by low oxygen, so some plant cells can survive even in anoxia (almost absence of oxygen) for prolonged periods of time. All this while harnessing the energy from the sun to convert the carbons in the air into sugars (Raven biology of plants). Pretty cool eh?!
Anyway, that’s not what I want to talk about today. There is another amazing feature that plants have, longevity. Plants in fact, can be quite crafty when it’s about defying aging and death. Like all of us, plants also seek to escape the grips of aging (Munné-Bosch, 2015). Studies found that aging and senescence are not the same for the plants(Jones et al., 2014), for instance, some plants hardly show signs of senescence (Baudisch et al., 2013).
How can this be? And what tricks do plants use to defy death?
There are no easy answers but let’s just say that plants abide by the same rules of life that dictate how and for how long we live. For example, there is a rule that says that aging cannot occur while there is growth(Munné-Bosch, 2015), all forms of life start becoming old only after they have served their purpose and stopped growing. So, what many plants do? They just keep growing indefinitely(Munné-Bosch, 2015).
If you have a molecular biology background I can imagine a smirk appearing on your face, you may say: “well, if plants keep growing, with all these cell divisions, they will surely accumulate tons of DNA mutations”. You can pat yourself in the back, I am not going to contradict you but…there was a group of scientists that had your same thoughts about DNA mutations so they just decided to pick an old tree and see how many DNA mutations they could find(Schmid-Siegert et al., 2017). They picked a tree currently in the campus of Lausanne University, it’s known as the Napoleon’s Oak because in the 1800, when the tree was only 22 years old, Napoleon and his troops stopped there on their way to invade Italy. The tree outlived Napoleon and at the time of the study it was 234 years old (there are several trees with the same name, to my knowledge there is one also in Poland, Napoleon must have loved Oak trees). The authors of the study sequenced the DNA from different branches of the tree expecting to find a huge amount of mutations, instead to their surprise there were extremely few mutations(Schmid-Siegert et al., 2017). The tree was accumulating mutations at a slower pace than even other common plants(Kuhlemeier, 2017).
Image showing all the sites from which the DNA of the Napoleon's Oak was sequenced, Image from reference (Schmid-Siegert et al., 2017)
How could this be possible?
In part this seems to be due to the modularity of the growth of the tree, the stem cells of the tree that will form a new branch are set aside fairly early during their divisions so that they are still relatively “fresh” when they will generate a new branch(Kuhlemeier, 2017). Moreover, there is another advantage in modularity, if a nasty mutation occurs in one portion of the plant, the whole compartment will be shut off from the rest of the plant and let rot. In other words, the plants are willing to sacrifice entire branches if that means survival for the rest of the plant. Plus, the tree will keep its most important cells well hidden for the perilous solar radiations, it will keep instead the “disposable” cells in the leaves and upper branches. So, if the radiations from the sunlight cause DNA damage in the disposable cells, the tree will just let them die.
But there is another trick up the plant’s sleeve or branch, that wasn’t discussed in those papers. I found out about it while reading other articles. As I mentioned before, the radiation from the sunlight may cause damage in the DNA, the cells are well equipped to repair these damages but they risk making a mistake during the DNA repair so we can have the insurgency of the so called "DNA mutations". If you live in a fantasy world these mutations may transform you into a super-hero, but in real life they will most likely lead to cancer. So what would be the most sensitive thing to do? Hide the DNA from the sunlight!
Image showing how light can trigger the movement of chloroplasts, from reference (WADA, 2016)
Studies have found that the plant’s nuclei and chloroplasts can actually move as a response to light (Wada, 2017; WADA, 2016). Especially the chloroplasts, will move towards light when this is weak, but they will shy away from strong light to prevent damage to the DNA.
Do you still think plants are not cool? It doesn’t matter, many trees will probably outlive us. You’d better find an Oak tree and name it after yourself!
References
- Baudisch, A., Salguero-Gómez, R., Jones, O. R., Wrycza, T., Mbeau-Ache, C., Franco, M., & Colchero, F. (2013). The pace and shape of senescence in angiosperms. Journal of Ecology, 101(3), 596–606. https://doi.org/10.1111/1365-2745.12084
- Jones, O. R., Scheuerlein, A., Salguero-Gómez, R., Camarda, C. G., Schaible, R., Casper, B. B., … Vaupel, J. W. (2014). Diversity of ageing across the tree of life. Nature, 505(7482), 169–73. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/24317695
- Kuhlemeier, C. (2017). How to get old without aging. Nature Plants, 3(12), 916–917. https://doi.org/10.1038/s41477-017-0076-7
- Munné-Bosch, S. (2015). Senescence: Is It Universal or Not? Trends in Plant Science, 20(11), 713–720. https://doi.org/10.1016/j.tplants.2015.07.009
- Schmid-Siegert, E., Sarkar, N., Iseli, C., Calderon, S., Gouhier-Darimont, C., Chrast, J., … Reymond, P. (2017). Low number of fixed somatic mutations in a long-lived oak tree. Nature Plants, 3(12), 926–929. https://doi.org/10.1038/s41477-017-0066-9
- Wada, M. (2017). Nuclear movement and positioning in plant cells. Seminars in Cell & Developmental Biology. https://doi.org/10.1016/j.semcdb.2017.10.001
- WADA, M. (2016). Chloroplast and nuclear photorelocation movements. Proceedings of the Japan Academy, Series B, 92(9), 387–411. https://doi.org/10.2183/pjab.92.387
Very interesting indeed. Posts like this one are always enjoyable and educational. It just goes to show that science will never disappoint.
Thanks for teaching us something today.
Although plants tend to fade into the background, akin to some decorative wallpaper, their influence on human and animal adaptation has been vast. It may be that the plants want to hide their nefarious and insidious power over their animal slaves that they remain silent and immovable. The yellow corn, for instance, has enslaved humanity for the past hundred years with her preference for petrol-based fertilizer inciting her human slaves to constantly seek new sources of the black bile. Some studies suggest that fully 25% of all carbon in human DNA derive from yellow corn, which suggests that humans are mere appendages to the hive-mind of the nefarious yellow corn.
Yellow corn also is used as feed for all farmed animals, which increases the "demand" for yellow corn cultivation, resulting in more arable and fertile land (a limited resource) to be dedicated to corn planting. Humans can not consume yellow corn without extensive chemical processing, and all of the animals cannot digest the yellow corn feed, dying at early age, while becoming fat, due to stress-induced obesity from cortisol release. Even with all this information, man continues to dedicate vast arable land-mass to his lord and master: yellow corn.
Though man imagines himself as the pinnacle of creation, it seems that he is nothing but a slave, toiling for the benefit of his overlords in the plant kingdom. It may be that not the meteor, but the dissatisfaction of the plant overlords off'ed our dinosaur forebears with their massive appetite for plant food-source. Insidiously, the plant masters changed their composition to be unsuitable for ingestion by the big, lumbering dinosaur servants, causing their extinction and replacing these inefficient slaves for smaller, shorter-lived mammals and avians.
Indeed plants had such a big influence on how the human race evolved, and on the other hand our farming activities also exerted evolutionary pressure on which plants became more diffused. I agree also when you mention that we don't always harvest the most nutritious plants but farmers are not dumb, as everyone they respond to incentives, in this case governments give many incentives for certain crops, this decreases the prices of food that reaches our tables but on the other hand we are incentivizing farmers to decrease the diversity of their crops, there is much to say about this topic
This is fascinating actually, not at all boring! A good entertaining read!
Thank you for your comment, I am glad to see someone else enjoys the topic :)
Honestly in most of biology I found a lot of the plant stuff boring until it came to talking about the specifics of photosynthesis (such as the Calvin cycle) so I can understand not finding plants as interesting. Even with studying the specifics, I still found studying the glycolytic pathway to be more interesting. That being said what I found truly interesting in your post is how you talked about how oak trees (and possibly others) prevent the accumulation of genetic mutations through the "storing" of stem cells. I am slightly curious on how that works but otherwise I actually found this concept to be really cool!
Hey Sven, thank you for stopping-by, I am not an ecophysiologist but while everyone is focused on the animal kingdom I like every now and then to keep on eye on plants, sometime you realize they came up with some interesting mechanisms for surviving in very harsh environments, for example we could learn from their ability to survive in low oxygen environments to design gene therapy strategies to treat or prevent stroke or to increase cell survival during transplants. There is a lot I don't know about how plants deploy their stem cells I will certainly read more about it, in the meantime if you would like to read some of the papers I cited I could send them to you if you don't have access to them
My university account gives me access to most paywalled articles so unless the article is posted in only a single niche place or something I should be able to access it. As soon as I get home I will check out the papers to read more, until then thanks for the reply!
thank you!! I think leaving this comment when you vote is a great idea!!
We need to make more of an effort for people to know the project exists. This has been pointed out to me several times recently.
I think you are on the right path, just last night I saw someone delegated 1000 SP to steemstem, it would not have happened if you were not doing a good job
Yes, that was witness @lukestokes. Whom if you haven't voted for witness you should consider. His witness is called lukestokes.mhth.
Other witnesses supporting the steemstem project that you should consider voting for include gandalf (his witness is gtg and has also has delegated 1000 SP to each the project and several members), and delegate.lafona (lafona is a part of the voting trail)
thanks for the suggestion, I've already voted for delegate.lafona and I will have a look at the other witness you mentioned
hey, that chicken is cheating! thanks for the mention :D
ahahha are you kidding? the Jesus Christ lizard is cool!
no I am not. there's a small light turning on below the piano buttons!
I guess it may never get as good as Mozart but it may still find a job in some cover bands..They would not mind some cheating
ahhahahahahahhahahaha
This brings up a lot of questions about the longevity of humans for example. If we were able to limit mutations and encourage continuous growth (in example, restoring the telomeres of chromosomes allowing for continuous cell division), is it possible in the near future we could defy death ourselves?
Good question :) I think it's likely that in the coming years we will develop a few tricks ourselves to prolong our lifespan but I guess solving one problem will lead to another, for example in the last few years while we increased the life-expectancy of people we have seen the gap between people in need of an organ transplant and organ donors widening, more people need blood transfusions and fewer people are fit to donate it. So I think the efforts should not be directed only at living longer but at living better as well..
That is very true. It is amazing to see the current development of medicine in our society. So much has grown and changed.
You didn't say it explicitly, but plants are the modern-age invincible superheroes :D
Ahaha Marvel is probably already working on a new comic :)
They stole your idea :D
ahahahah they left me with the piano-chicken, maybe @trumpman can give me a hand finding new talents, an interesting candidate could be goatman:
We need to offer the same equipment to @trumpman, for sure (am not so sure he will accept the same food :D )
ahahaha
I notice that for some reason, he is ignoring what is going on on this thread. I would do the same if I were him ;)
he is a smart guy!
I loved this topic and understood way more as in the last one (you told me I picked a difficult one).
Well, I had to laugh during reading it, because I tried to imagine how I would let - let's say - rot a toe away because of mutated cells and just go on living. .... Why not? Do we need a little toe to survive? LOL.
Also it makes me to have this feeling of "awe" when it comes to the wonders of nature and living systems. Trees for sure are fascinating "creatures". Since I read Lord of the Rings and saw Fanghorn I am having to the visual sensation also the audio memory of how really old trees may talk (or hum).
This expression of yours also made me think and I resonate with it. Same with us, no? It reminds me on a translation I want to make from something I wrote some time ago - it's about a body thief who steals the body from a vampire (originally told by Anne Rice)
if you were like a plant you could grow a new toe if you didn't like the previous one :) I think today we are a step ahead our biologic limits so there is a lot we can do even at an old age
excellent post I follow you, if you want you can follow me