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Author Topic: Can any plants use geothermal energy instead of direct sunlight to survive?  (Read 2920 times)

Offline Mononoke

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I've been wondering whether geothermal energy is used or could theoretically be used by certain plants instead of light energy as provided by sunlight or any other light source in the process of photosynthesis or in an alternative process I'm not aware of. As, from my own understanding, (geo)thermal energy and light energy are not the same thing I'm guessing not but I'd like this to either be confirmed or denied please. This ties in with basically my larger question of what sort of plants can survive without sunlight and how they do so, assuming there are any.     


 

Online evan_au

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Our normal definition of plants is that they contain pigments like chlorophyll to absorb energy from light (some bacteria have pigments that may not be green).  Some of these bacteria produce sulphur as an end-product, rather than oxygen.

Photosynthesis involves a complex cascade of enzymes and ions; maintaining this would be a heavy load on any organism which is never exposed to light. However, there has been one species of bacteria which lives on the faint phosphorescence around undersea hydrothermal vents. Most bacteria that live around these "black smokers" extract energy from sulphide chemicals, without any light.

Of course, in a country like Iceland, they generate some of their electricity from geothermal energy; you could use some of this electricity to run an indoor hydroponic farm with electric light - but this is probably not what you were thinking of...
 

Offline Mononoke

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Yeah, I was really thinking about plants being able to grow in caves, in complete darkness, but getting their energy from geothermal sources underground, and I was wondering if this would be theoretically possible even if there are no documented cases necessarily (I've certainly been unable to find any such link). Thanks for the info about the bacteria though.
 

Offline CliffordK

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There is a group of Guanophilic fungi.  However, the fungi are classified as neither plant nor animal. 
 

Offline yellowcat

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Not plants and not geothermal energy but there is evidence that some fungi can get energy from radiation. They will grow towards a radioactive source.
Radiotrophic fungi are thriving at the site of Chernobyl Nuclear Power Plant, even growing on the walls of the reactor building.

http://www.scientificamerican.com/article/radiation-helps-fungi-grow/ [nofollow]
http://www.sciencedaily.com/releases/2007/05/070522210932.htm [nofollow]
http://www.asknature.org/strategy/3edf10d5be81cda6b5aabadfb9a0c424#.UzHxIoUxp2E [nofollow]

Mice fed on black fungi were able to survive what would normally be a lethal radiation exposure:
http://online.liebertpub.com/doi/abs/10.1089/cbr.2012.1318 [nofollow]
http://www.microbeworld.org/podcasts/this-week-in-microbiology/archives/1501-twim-67 [nofollow]
 

Offline Mononoke

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Not plants and not geothermal energy but there is evidence that some fungi can get energy from radiation. They will grow towards a radioactive source.
Radiotrophic fungi are thriving at the site of Chernobyl Nuclear Power Plant, even growing on the walls of the reactor building.

newbielink:http://www.scientificamerican.com/article/radiation-helps-fungi-grow/ [nonactive]
newbielink:http://www.sciencedaily.com/releases/2007/05/070522210932.htm [nonactive]
newbielink:http://www.asknature.org/strategy/3edf10d5be81cda6b5aabadfb9a0c424#.UzHxIoUxp2E [nonactive]

Mice fed on black fungi were able to survive what would normally be a lethal radiation exposure:
newbielink:http://online.liebertpub.com/doi/abs/10.1089/cbr.2012.1318 [nonactive]
newbielink:http://www.microbeworld.org/podcasts/this-week-in-microbiology/archives/1501-twim-67 [nonactive]

That's really interesting and is a big help for my research so thanks! I've still been unable to find any information on plants utilising geothermal energy to survive so yeah, it would seem that ain't possible at least to current scientific knowledge. However, hypothetically speaking, if some fungus have adapted to be able to utilise radioactive energy, there's no reason they or even other plants couldn't have hypothetically adapted to do the same with geothermal energy sources.
 

Offline CliffordK

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I believe there is a lot of "life" around undersea geothermal vents, often deep enough that they receive essentially no sunlight.  Sea anemone, and similar organisms are considered to be animals and not plants. 

Anyway, I think those organisms around geothermal vents utilize the chemicals from the vents for energy rather than the heat, or feed on other smaller organisms.

For heat alone to be an energy source, one would generally think of needing some kind of gradient. 

Most, or all plants also use a process called transpiration to distribute water and nutrient molecules throughout the plant.  Usually it is considered to utilize solar energy as part of the transpiration, but presumably it could also occur at night.  Actually, it seems that some plant species have minimal nighttime transpiration, and others have fairly high nighttime transpiration.  Theoretically a plant could at least augment its transpiration using geothermal energy too.
 

Offline cheryl j

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There was also this article in Science Daily recently about "electricity eating" bacteria.

http://www.sciencedaily.com/releases/2014/03/140310144000.htm

"The commonly found bacterium Rhodopseudomonas palustris can use natural conductivity to pull electrons from minerals located remotely in soil and sediment while remaining at the surface, where they absorb the sunlight needed to produce energy."

This was an interesting article about cave microbes:
 "The microbes have adapted means of using the chemical compounds present in the cave in some cases, even eating rock to get energy from compounds such as manganese or pyrite, Neilson said. [7 Theories on the Origin of Life] "Instead of relying on organic carbon, which is a very scarce resource in the cave, they use the energy in nitrogen-containing compounds like ammonia and nitrite to convert carbon dioxide from the air into biomass," she said."

http://www.livescience.com/41651-extreme-microbes-found-arizona-cave.html


(The radioactive fungi articles were great by the way! I never heard of that)
 

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