Biology
I was just going through my biology book and ran into a few topics I
thought the list might want to read.
Recently I read someone here say that rock salt added to the soil may
add minerals. I just read that "Worldwide, no toxic substance restricts
flowering plants growth more than salt does. Salty habitats support, at
best, sparse vegetation. Saline environments pose an osmotic problem.
Because of a high salt concentration, the environment has an unusually large
negative water potential. To obtain water from such an environment, resident
plants must have an even more negative water potential than that of plants in
non-saline environments, otherwise the plants lose water and wilt. Chloride
ions may also be toxic at high concentrations."
In regard to viruses:
Aspirin, acetylsalicylic acid, is one of the best selling drugs in the
world and has been for many years. In our bodies aspirin is hydrolyzed to
produce the substance that actually caused the effects, salicylic acid. It
now appears that all plants contain at least some salicylic acid. This
compound plays various roles in the plants themselves, most notable a role in
the hypersensitive response (plants that are resistant to fungal, bacterial,
or viral diseases generally owe this resistance to what is know as
hypersensitive response. In this response cells around the site of microbial
infection produce phytoalexins and other chemicals and then die, leaving a
dead spot that contains what is left of the microbial invasion. The rest of
the plant remains free of infection) The acquired resistance that sometimes
follows the hypersensitive response is accompanied by the synthesis of PR
proteins. Treatment of plants with salicylic acid or with aspirin leads to
the production of PR proteins and to a resistance to pathogens. Salicylic
acid treatment provides substantial protection against tobacco mosaic virus
and some other viruses. It has been proposed that salicylic acid also serves
as a signal for disease resistance. In some cases, microbial infection in
one part of a plant leads to the export of salicylic acid to other parts of
the plant, where it causes the production of PR proteins before the
infections can spread. The PR proteins would, according to this hypothesis,
limit the extent of the infection.
So what do you all think???
Greg
Fresno, Ca
www.thepumpkinmaster.com
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