Hormone Respones in SPS?

[nbd13]

Hey guys,

I was thinking about something the other day. In Plant Bio we learned alittle about hormones and the response/s they cause. One in particular caught my attention, Indol Acetic Acid (IAA) its an Auxin. Actual the first hormone ever discovered by Fritz Went.

Anyway this hormone in plants anyway has a couple responses,

1. Cell elongation
2. stimulate roots to grow
3. inhibit lateral buds

The ones that got me thinking were the cell elongation and the inhibition of lateral buds. Basically the short version of the story is that this hormone inhibits "buds" that grow on the plant and these buds are what branches will grow out of.

So this leads to apical dominance in plants (the plant growing very tall and skinny). BUT there is a catch here, if you pinch off the tip of the plant (where IAA is produced) you will make the plant grow "bushy" with many branches.

This lead to me to relate this hormone to SPS. I hear sometimes that if you cut the tip off corals (espically stags) they will start to branch out and become "bushy".

The other response is cell elongation. There is a hypothesis out there called the Acid Growth Hypothesis which says you basically loosen the pectin bridges (in the cell wall) by adding acid (H+) the Tugor pressure will push outward and the cell will split. This leads to growth in the plant.

That also made me think if this could happen in SPS.

Now my questions,

1. does anyone know if IAA is present in SPS or any corals for that matter.

2. If it does NOT is it possible that there is a hormone present in SPS that lead to the same responses?

3. Are hormones even present in SPS?

Sorry for the little rant here. some of this may not make any sense and i appologize for that. I am just curious here. I am sure something must cause these syptoms is our corals. Just trying to figure out what it might be.

I mean why do people say you should cut the tip off of SPS to make them grow more "bushy"?

Anyway sorry again for the rant here

Nick

[mesocosm]

Greetings All !

The ones that got me thinking were the cell elongation and the inhibition of lateral buds. Basically the short version of the story is that this hormone inhibits "buds" that grow on the plant and these buds are what branches will grow out of.

Auxin is a plant hormone ... PLANT hormone. Warning ... Danger, Will Robinson ... tempting though it is ... we should never, EVER generalize a relationship between scleractinian growth habits and plant growth habits, despite the "apparent" visual similarities ...

... ... these processes are VERY different.

Anyway this hormone in plants anyway has a couple responses,

1. Cell elongation
2. stimulate roots to grow
3. inhibit lateral buds

... If it does NOT is it possible that there is a hormone present in SPS that lead to the same responses?

Nope ... in corals, the processes are fundamentally dissimilar. There is no cell elongation, there are no roots, and there are no lateral buds.

The other response is cell elongation. There is a hypothesis out there called the Acid Growth Hypothesis which says you basically loosen the pectin bridges (in the cell wall) by adding acid (H+) the Tugor pressure will push outward and the cell will split. This leads to growth in the plant.

We're talking about fundamentally different structural compositions.

The cell walls of plants are constructed primarily out of a carbohydrate polymer called cellulose. Plant cell wall may also contain pectin ... as you noted ... hemicellulose, and a variety of proteins including hydroxyproline-rich glycoproteins (HRGP), arabinogalactan proteins (AGP), glycine-rich proteins (GRPs), and proline-rich proteins (PRPs).

For a more detailed review of plant cell wall structure, see ... this.

Animal cells do not have cell walls ... they have cellular membranes. Cell membranes are essentially bilayered phospholipids with a variety of embedded proteins, including cholesterol (Eukaryotes) and hopanoids (Prokaryotes) for membrane fluidity.

For a more detailed review of animal cell membrane structure, see ... this.

It is these differences in fundamental structure that makes the comparison between plant growth processes vs. coral growth processes ... so disturbingly common in reefkeeping cyberspaces ... so ... well ... wrong.

The only catergory of marine organisms that are subject to manipulation by plant hormones are marine algae. Hardly surprising, given their cell wall structure.

For a more detailed review of marine algae cell wall structure, see ... this.

I mean why do people say you should cut the tip off of SPS to make them grow more "bushy"?

I've been trying to figure out why some people post what they post for years ...
My conclusions led me to this ... ... go figure ...

Seriously folks ... correlation does not imply causation. The growth pattern that occurs after an SPS tip is cut off is influenced by a multitude of factors including light, current, spatial orientation, genetic predisposition (including hormone and protein synthesis ...), water quality, proximity of competitors (allelopathy) ... the list goes on.

... Are hormones even present in SPS?

Having ranted all that ... hehe ... you're not alone .. hehe ... the general classes of chemicals that you're talking about ... steroids, hormones, etc ... ARE initimately involved in scleractinian growth and reproduction. Just remember that these chemicals are fundamentally different compared with what we observe in plants.

For example ...

Hormones and Reproduction in Scleractinian Coral, Euphyllia ancora.
By Ching-Fong Chang,
Department of Aquaculture, National Taiwan Ocean University
Brief Abstract


The Presence and Ancestoral Role of GnRH in the Reproduction of Scleractinian Coral, Euphyllia ancora.
Endocrinology, 2005
Full Text


This is to say nothing of the numerous anecdotal observations regarding the use of Human-Growth Hormone (HGH) is SPS tanks ...

... those zany Europeans ... you're gotta love them ...



JMO ... HTH

[mesocosm]

Greetings All !

In Plant Bio we learned alittle about hormones and the response/s they cause. One in particular caught my attention, Indol Acetic Acid (IAA) its an Auxin.

If you liked auxin ... wait until you discover gibberellins. If you want to make genetically bizzare, mutant-monster plants, try gibberellic acid ... wicked stuff.

[Orion76]

steroids, hormones, etc ... ARE initimately involved in scleractinian growth and reproduction.

Cool, I'm putting some dianabol in my calcium reactor tonight

[nbd13]

Thanks for the response, just the guy i was looking for actually, haha.

I complete understand that they are different, i guess i was trying to get to the point of is there a hormone similar to say an auxin in SPS. For example when you cut the tip off of an acro is a hormone blocked? or released?

i know there are not roots or lateral buds in SPS, haha.

Just trying to understand chemical what happens when you cut the tip off. Or what causes acros to grow? is it purely photosynthesis?

We already talked about gibberellins. like you said pretty intresting stuff. I personally cant wait till microbiology next year alonf w/ genetics.

anyway thanks for your explination when i get a minute i will read those links.

Nick