Abscisic Acid
Abscisic Acid has a powerful role in helping plants withstand and
respond to environmental stresses. Abscisic acid and gibberellic
acid are produced from the same starting material, so when Cambistat
inhibits gibberellic acid formation more abscisic acid can be produced.
Abscisic acid is considered the plant stress hormone, and it induces
responses that protect the tree. Some of the more notable responses
include:
| untreated |
treated |
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These electron microscope photographs
show the leaves of treated and untreated trees. Notice
how much thicker the treated tree leaf is.
(click photos to view a magnified version) |
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| untreated |
treated |
 |
 |
These electron microscope photographs
show the undersides of leaves of treated and untreated
trees. Notice how many more trichomes (hairs) have grown
on treated trees. This response my help explain decreases
in water loss and increased defenses of leaves on treated
trees.
(click photos to view a magnified version) |
|
| Research and Photographs courtesy
of Qi, Knighten,and Chaney |
Chlorophyll Production
Chlorophyll molecules have two distinct components: a ring structure
with a magnesium atom at the center, and a long side chain called
a phytol tail. The phytol tail is formed from a series of reactions
that begin with the molecule geranylgeranyl pyrophosphate. When
gibberellic acid formation is inhibited, more phytol can be formed
and chlorophyll levels can be enhanced, resulting in a darker green leaf.
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 |
| untreated |
treated |
The red oaks were side by side
in a research plot at the University of Minnesota. Treatment
was applied 3 years before photo was taken.
(click photos to view a magnified version) |
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it frees up energy, carbon and other substrates
that would have been used for that growth. These get shunted
back into the tree and are available for other functions. There
is also an increase in Chlorophyll and Abscisic acid, which
causes the tree to produce thicker, darker green leaves. |
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