Things that mess with the formation of trans-cinnamic acid?

[Darklight]

I get to ask the difficult questions

Trans-cinnamic acid is a step in the shikimate metabolic pathway which forms many of the interesting compounds we find in our lil plant buddies.

Unfortunately trans-cinnamic acid is also an anti-auxin. Which means it can be a problem getting plants to elongate and more importantly form roots.

Overpowering it with auxins is the normal way to overcome the root formation problem- 2-4D, NAA, cis-cinnamic acid and IAA are normally used to combat poor rootset in in-vitro plants.

It doesn't always work, of course. With Acacia phlebophylla no amount of auxin supplementation of media worked, I had to back down the metabolic pathway a fair bit and add l-glutamine in order to get rootset ( metabolises into IAA -and DMT I presume ). I've tried going around that path the same way in other species, but to no avail

But as many of you know I am not a chemist's bootlace, and most of the texts I read may as well be in another language ( yeah, like chemistry language ) and I reckon there is always another way around stuff.

Can anyone here think of a way to lower the production of trans-cinnamic acid, to increase its uptake into a pathway that would render it harmless, or to provide a non-hormonal supplement for in-vitro plants that opposes its action somehow? And explain it in 25 words of two syllables or less?

[Auxin]

heh- ya do ask the hard ones, but its a nice change from the folks that ask how to get high off lawn clippings

Lets see, cinnamic acid is formed from phenylalanine... it'd make sense to try to reduce biosynthesis of phenylalanine or inhibit the conversion of phenylalanine to cinnamic acid, hmm...

 

quote:

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Phenylpropanoids are derived from cinnamic acid; the enzyme phenylalanine ammonia-lyase (PAL) catalyzes the gateway metabolic step from primary metabolism into phenylpropanoid metabolism, the de-amination of phenylalanine to produce cinnamic acid.

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So inhibiting PAL would result in a reduction of cinnamic acid biosynthesis... just gotta find a way to inhibit or decrease production of that...

 

quote:

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Two inhibitors of the first enzyme phenylalanine ammonia lyase (PAL) in the phenylpropanoid pathway were used to investigate the role of phenolic metabolism in lignification and toughness of Asparagusspears. Spears were soaked for 1 h at 20°C in aqueous solution of "-aminooxi-$-phenylpropionic acid (AOPP) at 0, 100, 300 and 600 µM. Liquid 2,5-Norbornadiene (NBD) was applied with a micropipette onto a sheet of filterpaper in a 6.4 liter big jar which was immediately sealed with a cover. Liquid NBD readily volatilized at 25°C ina closed chamber. The amount of liquid applied was calculated to give the desired gaseous concentration(6000 µl LG ) in the jar. Both AOPP and NBD inhibited PAL activity...

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http://www.ansinet.org/fulltext/ajps/ajps3150-54.pdf

So theres two established PAL inhibitors. 2-aminoindane-2-phosphonic acid seems to be another potent one.

Inhibiting the production of phenylalanine certainly would do it too, you prolly wouldnt want full inhabition though. phenylalanines precursor is phenylpyruvic acid, its precursor is prephenic acid. Prephenic acid is the precursor for both phenylalanine and tyrosine. If you inhibited prephenate dehydratase (PDT) but not prephenate dehydrogenase the production of phenylalanine would decrease and there would be a corresponding increase in tyrosine production.... the problem there is tyrosine is a potent activator of PDT... so that idea is out, lol.

Further up the biosynthetic pathway is chorismic acid, chorismate mutase will take it the phenylalanine/tyrosine route and anthranilate synthase will take it to anthranilic acid... which ends up at tryptophan. A chorismate mutase inhibitor would reduce the production of phenylalanine and tyrosine while increasing tryptophan production (thus giving a ample supply of IAA precursor while inhibiting the pathway that ultimatly leads to your auxin inhibitor), a google search for inhibitors of that type didnt look promising though.

The conversion of chorismic acid to anthranilic acid is dependant on glutamine, have ample glutamine available and it could help optimize the conversion rate of chorismic acid to anthranilic acid and thus reduce the amount of chorismic acid left to go the phenylalanine route... maby.... if your lucky... and assuming there isnt already enough glutamine around to make the anthranilic acid rout free and easy... ummm...

Is there a biochemist in the house?

[ 08. March 2005, 07:35: Message edited by: Auxin ]

[apothecary]

Heh...this is gonna sound really weird, but...my mother is a biochemical geneticist or something like that.

Would you like me to print this thread out and ask her if she can decipher whatever the hell it is you two are talking about, and maybe add something?

[occidentalis]

Auxin:

its a nice change from the folks that ask how to get high off lawn clippings      

You can get high off lawn clippings?

How?

[apothecary]

http://shaman-australis.com.au/shop/produc...products_id=130

As long as that's your grass

[Darklight]

Auxin:

heh- ya do ask the hard ones, but its a nice change from the folks that ask how to get high off lawn clippings ...

Is there a biochemist in the house?

Thanks for the considered reply Auxin, I was thinking along these lines ( only in fewer syllables ). Glutamine and trypto combined *might* work- what we're after is the conversion of l-tryptophan to IAA where possible on the pathway

Apothecary yes please- I'd love more professionals to voice their opinions on the matter!

Thanks again everyone

[Fenris]

I think there is a PHD in this question.

[teonanacatl]

i was flicking through the biochemistry book at uni and its a huge subject so i just flicked through, i noticed somewhere that it said it was made in the leaves so i guess you could snip off the leaves lol

[Auxin]

What about a anti-cytokin?

As I remember what matters far more then the concentration of auxin is the auxin/cytokin ratio... inhibit cytokin production and the auxin-effect should be more pronounced... add to that NAA that you add to the media and you might get something better then when you only add NAA by itself.

Or what about something that could compete with phenylalanine in conversion to the corresponding cinnamic acid derivatives, something that would produce a end-product that lacks anti-auxin activity... L-DOPA might not work, the compounds kinda sensitive- dunno how long it would last in culture media in the light... a deamination competator is a thought though.

Ever considered/investigated the possibility of a end-product feedback problem that could be induced by adding tryptophan? Theres a chance it could inhibit the biosynthesis of tryptophan and shift the pathways toward the phenylalanine/tyrosine route, that'd be bad.

erm... what else... soluable humates have been shown to increase the ion transport into roots and increase total root mass in many plants. (0.01% (w/v) calculated as free humic acid is the usual starting point when trying humates on a new plant, I like ammonium humate - better then sodium humate anyway)

umm... roots need air.. how do y'all prevent anoxia problems in the roots... have you been doing this? (Ok, I admit it, I Really should have taken microbiology, higher biology, et al at uni, my knowledge of growing things in agar sucks! lol)

[Darklight]

Auxin:

What about a anti-cytokin?

I've been looking for one but all my limited understanding has led me to believe they're called auxins. Doesn't seem logical, there should be something along a pathway somewhere, but there ya go

add to that NAA that you add to the media and you might get something better then when you only add NAA by itself.

Yeah, am playing with 2-4D in small amounts and adding NAA

Or what about something that could compete with phenylalanine in conversion to the corresponding cinnamic acid derivatives, something that would produce a end-product that lacks anti-auxin activity..... a deamination competator is a thoght though.

That's kinda what I'm after, though what it's called I can't possibly imagine

Ever considered/investigated the possibility of a end-product feedback problem that could be induced by adding tryptophan? Theres a chance it could inhibit the biosynthesis of tryptophan and shift the pathways toward the phenylalanine/tyrosine route, that'd be bad.

Have tried to flood the Try pathway by reducing media strength by 50% and adding lots of l-glutamine and a bit of l-Tryptophan. Will know how it goes in a few weeks

erm... what else... soluable humates have been shown to increase the ion transport into roots and increase total root mass in many plants. (0.01% (w/v) calculated as free humic acid is the usual starting point when trying humates on a new plant, I like ammonium humate - better then sodium humate anyway)

Have used humic acid on one species to no avail. I may have not used enough. But is ammonium humate different from sodium humate and humic acid? I'll need to find my Merck. Some spp don't like ammonia in any form. Also complicating things is the fact that with that sp I used l-phenylalanine in a totally mistaken attempt to induce rooting. Did the leaves good tho, and made the culture last six months!

umm... roots need air.. how do y'all prevent anoxia problems in the roots... have you been doing this? (Ok, I admit it, I Really should have taken microbiology, higher biology, et al at uni, my knowledge of growing things in agar sucks! lol)

My limited understanding is that agar and gelling agents allow some movement of oxygen to the explant end. Liquid culture can allow more, especially if it is aerated. Liquid culture works wonders in some spp- I used to use hormone free liquid culture to 'rest' my TC of Mitragyna speciosa every five subcultures, back in the day. But that only seems to work for that and related spp- it hasn't increased success in too many others

Thanx Auxin, yer a total legend. You've given me a few things to think about here!

[Auxin]

Darklight:

But is ammonium humate different from sodium humate and humic acid?

Ammonium humates only real advantage over sodium humate is theres no sodium... and not enough ammonium to cause problems generally (1.0g humic acid makes about 1.1g ammonium humate- and its usually used as a 0.01% solution).

Humates are a bit different critters then free humic acid, being that humates are soluable in water (Note: calcium humate is not soluable). As soluable salts they have a stronger effect on the roots and through them the whole plants.

 

Darklight:

Thanx Auxin, yer a total legend. You've given me a few things to think about here!

My pleasure ... though I dont know how much help I'm being- my biochem knowledge is pretty minimal, lol.