Are Plants Immortal? (How Long Can Plants Live)
Immortality is something that most people would want to achieve, but only a few organisms can be considered biological immortal. Most animals are mortal and will die sooner or later. But the plant kingdom can sometimes be strange. So are plants immortal? Or are certain plants immortal?
Most plants are not immortal but there are clonal and non-clonal plants that can live for a very long time (1000+ years). These plants could potentially defy biological mortality if they are in the right environment and have access to all required nutrients and water.
I mentioned the term “potentially” because immortality means that an organism is able to live forever (for eternity). Eternity is a very, very, long time and our ability to understand what happens to plants on this time-scale is unfathomable. Even studying plants that are thousands of years old, barely gives us a glimpse into the realm of eternity.
While hypothetically a single genetic individual of certain plants could live forever through the process of cloning, environmental conditions will never actually allow that to happen. The earth’s climate is extremely static, pathogens are constantly evolving, and natural disturbances make death an unavoidable likelihood.
In this article, you’ll learn why plants age and most of them will eventually die. You’ll learn about some of the oldest plants in the world and how certain plants use mechanisms to defy biological immortality.
Why Do Plants Age and Die?
Most organisms, including most plants, reach a biological peak in their lives. This peak is followed by a weakened defense system, reduced ability to obtain nutrients and an overall increased rate of mortality. Plants, who are stuck in one place, also have the threat of changing climates and environmental circumstances that make their habitat less ideal for survival.
Organisms exhibit this biological peak for several reasons:
- wear and tear: biological systems become damaged and less effective over time. This can lead to a decreased immune function which puts it in more danger of environmental stresses and disease.
- living cells have a limit: cells have a limit on how many times they can divide. This is programmed directly into the cell’s DNA through special sequences located at the ends of the DNA molecules known as telomeres. Every time a cell divides the telomeres shorten until they become too short and the cells can no longer divide.
- constant defense against (micro)organisms: these organisms want to consume the nutrients that organisms have without their bodies and cells. These pathogenic organisms are constantly evolving and if an individual were to live forever (and not evolve) they may lose the race against these newly adapting organisms.
What are the Oldest Plants on the Planet?
One of the best places to look for immortal plants is in the oldest plants on the planet. These are classified into two different categories:
- clonal plants
- non-clonal plants
Clonal plants
Clonal plants are clones of the same plant individual. An individual (clonal) plant can spread/reproduce vegetatively, allowing small pieces of their tissues to grow into completely new plants.
For example, aspen trees are clonal plants that can form entire forests of clones that are just a single genetic individual. The trees may only live for a couple of hundred years, but these clonal individuals are estimated to be almost 80,000 years old! This makes them excellent candidates for immortality. Unfortunately, it’s impossible to know their true age since the tissues only exist for a small fraction of the individual life span.
Other long-lived clonal plants are the Jurupa Oak in California (13,000 years old), Kings Lomatia in Tasmania (43,000 years old), and Norway Spruce in Norway. (10,000 years old).
Non-clonal plants
Non-clonal plants are single-trunked species that grow from seed and don’t spread underground to form colonies. These are individual trees that can live for thousands of years, growing from the same trunk in the same place.
Some examples of these are long-living non-clonal plants are:
- Bristlecone Pines (about 5,000 years old)
- Ancient Yews (2-5,000 years old)
- Giant Sequoias (2,000 years old)
While these non-clonal plants are not as old as the clonal individuals they do have the oldest structure and appearance.
How Plants Defy Death (Biological Immortality)
If the mortality rate of an organism does not diminish after it reaches maturity then it is considered biologically immortal. Another term frequently used to describe this is negligible senescence, which suggests that there are species that defy aging.
Such species do not show a reduction in fitness (ability to survive) as they age. Through the evolutionary process, plants have developed mechanisms to help them defy the aging process.
Time resistant DNA
The DNA of plants is particularly good at fixing and preventing genetic mutations that could be harmful to the plants. Clonal plants like I mentioned earlier also typically don’t just form a single clone, but hundreds of them. This ensures that at least one clone will have the right DNA.
Lastly, remember the telomeres I talked about? Turns out plants have specialized proteins that allow them to regrow their telomeres!
Slowing down with dormancy
Just like some animals hibernate during the winter, certain plants go into dormancy when the environmental conditions do not favor growth.
Many of the oldest plant species on the planet live in areas where there is a very short and limited growing season meaning they spend much of the year in dormancy.
During dormancy plants slow down their metabolism significantly, meaning they are no longer enduring the stress of aging.
Self cloning
Have you ever planted garlic from a bulb or started a plant from a cutting? If so, then you have cloned a being. When plants clone themselves they are essentially able to let go of old damaged tissues and form completely new parts to replace the aging tissues. This is what allows clonal plants to survive for thousands of years and produce new clones that look freshly born!
Want to Learn More?
If you want to learn more interesting facts about plants, you should definitely read the following articles:
- Are plants producers?
- Can plants get cancer?
