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Auxin

Auxin

(Science: plant biology) a group of plant growth substances (often called phytohormones or plant hormones), the most common example being indole Acetic Acid (IAA), responsible for raising the ph around cells, making the cell wall less rigid and allowing elongation.

auxins include indoleacetic acid, phenylacetic acid, and 4-chloro-indoleacetic acid. Commercially, auxins are used to promote root growth, to promote uniform flowering, and to set fruit and prevent premature fruit drop. Synthetic auxins such as 2, 4-D and 2, 4, 5-T have been used as herbicides, broad-leaved weeds like dandelions are much more susceptible to auxins than narrow-leaved plants like grass and cereal crops.

The defoliant agent orange was a mix of 2, 4-D and 2, 4, 5-T. 2, 4-D is still in use and is thought to be safe, but 2, 4, 5-T was more or less banned by the EPA in 1979. The dioxin TCDD is an unavoidable contaminant produced in the manufacture of 2, 4, 5-T, as a result of the integral dioxin contamination, 2, 4, 5-T has been implicated in leukaemia, miscarriages, birth defects, liver damage, and other diseases. A plant hormone that promotes root formation and bud growth.An auxin is a growth regulating substance that can be found in the meristems of plants. The concentration of auxin has the deciding effect on how much (and where) growth occurs in a plant.


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Auxin

Auxin controls xylem differentiation . Can anyone explain how ?

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by Xery05
Mon Nov 19, 2012 4:32 pm
 
Forum: Botany Discussion
Topic: Auxin
Replies: 0
Views: 1106

What is responsible for plants' branches having bends?

I would say yes, auxin is responsible for that. Furthermore, I would think that most tree trunks are straight because the sun is always moving, and therefore it isn't advantageous for what will later be the trunk to grow in any direction ...

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by plasmodesmata11
Wed May 09, 2012 9:40 pm
 
Forum: Botany Discussion
Topic: What is responsible for plants' branches having bends?
Replies: 3
Views: 1799

What is responsible for plants' branches having bends?

Is it because of auxin? I was walking down the block before and wondering why, if plant growth is influenced by light, that the trees themselves (the trunk) weren't bent. Then I realized—duh, they kind of are; the branches are. Is ...

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by animus
Mon May 07, 2012 8:15 pm
 
Forum: Botany Discussion
Topic: What is responsible for plants' branches having bends?
Replies: 3
Views: 1799

Re:

... probaby just bend due to the circular shape of the petri dish? Also what other aspects of the plant growth and development that are regulated by auxin ? In your response, you MUST include how its action would differ for different cell tpyes/ environmental stimuli? :D TY TY Btw , when a plant ...

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by duherro
Mon May 07, 2012 2:07 pm
 
Forum: Botany Discussion
Topic: Plant hormone experiment!
Replies: 17
Views: 6631

Re:

PINs are transporters of auxin which are localised on one side of cell forming polar auxin transport. And their localisation is driven by several factors... hmm what happens if auxin promotes apical dominance, then it cant grow anymore ...

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by duherro
Mon May 07, 2012 1:37 pm
 
Forum: Botany Discussion
Topic: Plant hormone experiment!
Replies: 17
Views: 6631
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