Plant's response to lack of water

  • #1
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Main Question or Discussion Point

Ive observed my own plants for quite some time now, and of course done my studies on nutrition. What Ive recently learned (observed) is that when a plant lacks water, the flowers seem to be the last ones standing, while possible death from other factors preserves older or newer leaves (depending on different factors and the environment) instead of the flowers. Does anyone know where I can find research on this kind of behaviour?
 
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  • #2
Drakkith
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What Ive recently learned (observed) is that when a plant lacks water, the flowers seem to be the last ones standing, while possible death from other factors preserves older or newer leaves (depending on different factors and the environment) instead of the flowers.
Are you saying that the flower petals and other parts of the flowering part of the plant are the last to go while the rest of the plant withers?
 
  • #3
russ_watters
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I'm a bit thin on sources and going to stretch a bit to avoid the "I've heard" sin....

Consider evolutionary pressure on this issue and logic will provide the answer. Plants and animals will go so far as to risk death or even commit suicide in order to reproduce, thus propagating the species:

http://news.nationalgeographic.com/...arsupials-mammals-sex-mating-science-animals/
"We found that males of species with shorter mating seasons are less likely to survive after mating," Fisher said. "Competitive effort has a survival cost— species that spend more energy on mating in the first breeding season risk never having another chance to breed."
This explanation/logic follows for any living thing, including both plants and humans.
 
  • #4
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As well as the survival of species imperative there is another fact:
Most plants have flowers which are at the most distant part of the plant from it's roots.
If the roots cannot provide enough water that will cause problems at first with the low parts of the plant, then it will spread upward.
 
  • #5
jim mcnamara
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rootone is spot on - most temperate species of plants generally lose turgor pressure from the lower leaves first, then it goes up.

Wilting. Plants can wilt and recover. There is however something in soil chemistry called the PWP - permanent wilting percentage (of water moisture in the soil)
Once that is reached the plant dies, and adding water to the soil does not "fix" the problem. PWP varies by species and soil types. For some species like cactus, long periods of extreme drought are required for the plant to die. So PWP plus duration is the rule there.

Watch the cactus puff up after rainfall. Cactus plants store water and so avoid the PWP problem for long periods.

Edit: oops here is the link

 
  • #6
jim mcnamara
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Moved to Biology forum.
 
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  • #8
BillTre
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Although @rootone's reply may be the most relevant, I am interested in a slight refinement of this reply, which I found interesting:
I'm a bit thin on sources and going to stretch a bit to avoid the "I've heard" sin....

Consider evolutionary pressure on this issue and logic will provide the answer. Plants and animals will go so far as to risk death or even commit suicide in order to reproduce, thus propagating the species:

http://news.nationalgeographic.com/...arsupials-mammals-sex-mating-science-animals/

This explanation/logic follows for any living thing, including both plants and humans.
I have bred various species of fish professionally and amateur-ly since I was a small kid.
There is a similar common assumption among fish breeders but with a slight twist:
Put a freshwater fish that is well conditioned for breeding (meaning among other things the females are carrying eggs ready to be laid) in poor water conditions (pH off or high levels of nitrogen products) and it can serve as a trigger for them to breed. Do the same with a salt water fish and breeding is not more likely.

An evolutionary explanation is that the freshwater fish live in quite variable environments and have evolved the adaptive response similar to those @russ_watters described, while the saltwater fish live in a very stable environment which hardly ever changes.

The highly stable saltwater environment has therefore not allowed natural selection to endow the organism's genetics with the adaptive responses that could get them through their troubling times.
The organism's genetic mechanisms are in part determined by the evolutionary history of the organism and can therefore have limitations.
 
  • #9
BillTre
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Although @rootone's reply may be the most relevant, I am interested in a slight refinement of this reply, which I found interesting:
I'm a bit thin on sources and going to stretch a bit to avoid the "I've heard" sin....

Consider evolutionary pressure on this issue and logic will provide the answer. Plants and animals will go so far as to risk death or even commit suicide in order to reproduce, thus propagating the species:

http://news.nationalgeographic.com/...arsupials-mammals-sex-mating-science-animals/

This explanation/logic follows for any living thing, including both plants and humans.
I have bred various species of fish professionally and amateur-ly since I was a small kid.
There is a similar common assumption among fish breeders but with a slight twist:
Put a freshwater fish that is well conditioned for breeding (meaning among other things the females are carrying eggs ready to be laid) in poor water conditions (pH off or high levels of nitrogen products) and it can serve as a trigger for them to breed. Do the same with a salt water fish and breeding is not more likely.

An evolutionary explanation is that the freshwater fish live in quite variable environments and have evolved the adaptive response similar to those @russ_watters described, while the saltwater fish live in a very stable environment which hardly ever changes.

The highly stable saltwater environment has therefore not allowed natural selection to endow the organism's genetics with the adaptive responses that could get them through their troubling times.
The organism's genetic mechanisms are in part determined by the evolutionary history of the organism and can therefore have limitations.
 
  • #10
BillTre
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Hey, my post got posted three (now its only two) times!
What's going on?
 
  • #11
jim mcnamara
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I just read this Thurs 8:00am MDT. Have done nothing.

@BillTre We hired a ghost writer for you? I have a damaged right hand, and sometimes one-click from me results in bogus clicks seen by the browser.
To answer your question I would give operator error a slight edge versus low battery levels in a wireless mouse. Both of which can do some fun things.
@Greg Bernhardt hasn't reported any problems like this AFAIK.

When stuff like this happens, it helps to report it in Feedback and Announcements. That way Greg gets a chance to fix it before it becomes an epidemic.
 
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