Unique Terpenoid Phenotypes?

[guineapig]

oh well.....i can't delete my post, which contained inaccuracies concerning the word "terpene".....i can't hide from it so i guess i'll just have to make the best of it.....

the whole point was trying to see if anyone had encountered a plant that just smelled unique and was never propagated or released to the community....sort of like a walk down memory lane.....maybe the odor was just too funky and was discontinued for that reason.....too many odoriferous plants are not being selected for that very reason- they are just too stinky!

anyway, here's a pic of my gp....

 

[OG bub]

its good to understand the complexities of 'terpene'

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Terpenoids are the largest, most diverse class of plant natural products and they play numerous functional roles in primary metabolism and in ecological interactions. The first committed step in the formation of the various terpenoid classes is the transformation of the prenyl diphosphate precursors, geranyl diphosphate, farnesyl diphosphate, and geranylgeranyl diphosphate, to the parent structures of each type catalyzed by the respective monoterpene (C10), sesquiterpene (C15), and diterpene synthases (C20). Over 30 cDNAs encoding plant terpenoid synthases involved in primary and secondary metabolism have been cloned and characterized. Here we describe the isolation and analysis of six genomic clones encoding terpene synthases of conifers, [(-)-pinene (C10), (-)-limonene (C10), (E)--bisabolene (C15), -selinene (C15), and abietadiene synthase (C20) from Abies grandis and taxadiene synthase (C20) from Taxus brevifolia], all of which are involved in natural products biosynthesis. Genome organization (intron number, size, placement and phase, and exon size) of these gymnosperm terpene synthases was compared to eight previously characterized angiosperm terpene synthase genes and to six putative terpene synthase genomic sequences from Arabidopsis thaliana. Three distinct classes of terpene synthase genes were discerned, from which assumed patterns of sequential intron loss and the loss of an unusual internal sequence element suggest that the ancestral terpenoid synthase gene resembled a contemporary conifer diterpene synthase gene in containing at least 12 introns and 13 exons of conserved size. A model presented for the evolutionary history of plant terpene synthases suggests that this superfamily of genes responsible for natural products biosynthesis derived from terpene synthase genes involved in primary metabolism by duplication and divergence in structural and functional specialization. This novel molecular evolutionary approach focused on genes of secondary metabolism may have broad implications for the origins of natural products and for plant phylogenetics in general.
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THE terpenoids compose the largest and most diverse family of natural products. Of the more than 30,000 individual terpenoids now identified (BUCKINGHAM 1998 ), at least half are synthesized by plants. A relatively small, but quantitatively significant, number of terpenoids are involved in primary plant metabolism including, for example, the phytol side chain of chlorophyll, the carotenoid pigments, the phytosterols of cellular membranes, and the gibberellin plant hormones. However, the vast majority of terpenoids are classified as secondary metabolites, compounds not required for plant growth and development but presumed to have an ecological function in communication or defense (HARBORNE 1991 ). Mixtures of terpenoids, such as the aromatic essential oils, turpentines, and resins, form the basis of a range of a commercially useful products (ZINKEL and RUSSELL 1989 ; DAWSON 1994 ), and several terpenoids are of pharmacological significance, including the monoterpenoid (C10) dietary anticarcinogen limonene (CROWELL and GOULD 1994 ), the sesquiterpenoid (C15) antimalarial artemisinin (VAN GELDRE et al. 1997 ), and the diterpenoid anticancer drug Taxol (HOLMES et al. 1995
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OG bub.

 

[OG bub]

A large number of terpenoid synthases of the monoterpene (CROTEAU 1987 ; WISE and CROTEAU 1999 ), sesquiterpene (CANE 1990 , CANE 1999B ), and diterpene (WEST 1981 ; MACMILLAN and BEALE 1999 ) series have been isolated from both plant and microbial sources, and these catalysts have been described in some detail. All terpenoid synthases are very similar in physical and chemical properties, for example, in requiring a divalent metal ion as the only cofactor for catalysis, and all operate by unusual electrophilic reaction mechanisms. In this regard, the terpenoid synthases resemble the prenyltransferases; however, it is the tremendous range of possible variations in the carbocationic reactions (cyclizations, hydride shifts, rearrangements, and termination steps) catalyzed by the terpenoid synthases that sets them apart as a unique enzyme class. Indeed, it is these variations on a common mechanistic theme that permit the production of essentially all chemically feasible skeletal types, isomers, and derivatives that form the foundation for the great diversity of terpenoid structures.

Several groups have suggested that plant terpene synthases share a common evolutionary origin based upon their similar reaction mechanism and conserved structural and sequence characteristics, including amino acid sequence homology, conserved sequence motifs, intron number, and exon size (MAU and WEST 1994 ; BACK and CHAPPELL 1995 ; BOHLMANN et al. 1998B ; CSEKE et al. 1998 ). Sequence comparison between the first three plant terpenoid synthase genes isolated [a monoterpene cyclase limonene synthase (COLBY et al. 1993 ), a sesquiterpene cyclase epi-aristolochene synthase (FACCHINI and CHAPPELL 1992 ), and a diterpene cyclase casbene synthase (MAU and WEST 1994 )] gave clear indication that these genes, from phylogenetically distant plant species, were related, a conclusion supported by very limited genomic analysis of intron number and location (MAU and WEST 1994 ; BACK and CHAPPELL 1995 ; CHAPPELL 1995A , CHAPPELL 1995B ). More recently, phylogenetic analysis of the deduced amino acid sequences of 33 terpenoid synthases from angiosperms and gymnosperms allowed recognition of six terpenoid synthase (Tps) gene subfamilies on the basis of clades (BOHLMANN et al. 1998B ; see Fig 6B). The majority of terpene synthases analyzed produce secondary metabolites and are classified into three subfamilies, Tpsa (sesquiterpene and diterpene synthases from angiosperms), Tpsb (monoterpene synthases from angiosperms of the Lamiaceae), and Tpsd (11 gymnosperm monoterpene, sesquiterpene, and diterpene synthases). The other three subfamilies, Tpsc, Tpse, and Tpsf, are represented by the single angiosperm terpene synthase types copalyl diphosphate synthase, kaurene synthase, and linalool synthase, respectively. The first two are diterpene synthases involved in early steps of gibberellin biosynthesis (MACMILLAN and BEALE 1999 ). These two Tps subfamilies are grouped into a single clade and are involved in primary metabolism, which suggests that the bifurcation of terpenoid synthases of primary and secondary metabolism occurred before the separation of angiosperms and gymnosperms (BOHLMANN et al. 1998B ). A detailed analysis of the latter monoterpene synthase, linalool synthase from Clarkia representing Tpsf, suggests that this is a composite gene of recent origin (CSEKE et al. 1998 ).

Overview of terpenoid biosynthesis in plants. The intracellular compartmentalization of the mevalonate and mevalonate-independent pathways for the production of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), and of the derived terpenoids, is illustrated. The cytosolic pool of IPP, which serves as a precursor of farnesyl diphosphate (FPP) and, ultimately, the sesquiterpenes and triterpenes, is derived from mevalonic acid (left). The plastidial pool of IPP is derived from the glycolytic intermediates pyruvate and glyceraldehyde-3-phosphate and provides the precursor of geranyl diphosphate (GPP) and geranylgeranyl diphosphate (GGPP) and, ultimately, the monoterpenes, diterpenes, and tetraterpenes (right). Reactions common to both pathways are enclosed by both boxes.

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eace, bub

 

[Verite]

The only difference I see in it OG is theyre actually getting paid to say stuff like that. Leads me to believe someones laughing on their way to the bank. :wink:

 

[Guest]

Good read Bub. What was the original question about terpenoids? All I got was BYE. Is the guineapig leaving us?

 

[Brownpants]

I sure don't trust people that edit their posts like that.

Seems to me Guineapig was caught spreading Bullsheet....

Good job OG Bub!

Now what the hell is cDNA?

 

[Nugs of Science]

where did GP go?

where did GP go?

It was nice to see some scientific discussions about our favorite plant. Complementary DNA (cDNA) is DNA synthesized from a mature mRNA template. cDNA is often used to clone eukaryotic genes in prokaryotes. There is our science lesson of the day.

NoS

 

[GreatLakes THC]

<---- Add's eukaryotic, and prokaryotes to the study list.

<---- Add's eukaryotic, and prokaryotes to the study list.

Just when I thought I was going to get a break from reading.

GreatLakes THC

 

[Brownpants]

Thanks Nugs.....I was thinking cDNA was a natural occuring form of DNA. But, now I see the light. They create cDNA from mRNA floating around the cell and then sequence it and determine what the heck it does. This way they don't have to worry about the introns, and can build a library of cDNA sequences. Clever!
It has been a while since I took genetics.

 

[OG bub]

Good read Bub. What was the original question about terpenoids? All I got was BYE. Is the guineapig leaving us?

I sure don't trust people that edit their posts like that.

Seems to me Guineapig was caught spreading Bullsheet....

Good job OG Bub!

Now what the hell is cDNA?

well.. in honesty..
I harshly addressed the "falsly" clamied observations in terpene in cannabis samples, which the last time I seen such claims were from p-4-p... whome has been the largest misrepresenting (scammer) source of terminology in recent times...
GP was trying to relate terpene in comparison to certian samples of cannabis....

I addressed it with the same FACTS I addressed p-4-p with,...... and have recieved the same responce........................ nothing.........
actually.. he deleted a quite "complex" misrepresentation of "terpene" in cannabis.
be-it out of embarressment, or dishonesty, is not my place to call..
but I posted the FACTS......

I sent GP a sincere apology via PM, as I wish NOT to disrespect anyones views, only reveal Facts.
hes been online Plenty since, but Ive recieved NO reply.. Id like to at least recieve confirmation of my mssg.. but sometimes we cant expect this much......

I let folks take it how they will. I need not imply acusitions... yer all smart enuff to read what u see.

I retracted my original "quotes" in hopes GP would understand the respect I intended.... as sited in my 'reason for 'edit'..

I look foreward to commentary by GP, as I said to this member in PM, I respected his posts previous to this.

the "money is on the wood"
Peace, bub

 

[JLP]

Well done OG bub.


JLP

 

[Guest]

wow... that was pretty long.. and you used a lot of big words... i'm impressed... seriously though.. im gonna break out the dictionary and re-read that.

 

[Guest]

Thanks again Bub. I guess it was better I showed up late.

 

[B.C.]

Well shit fire !

Well shit fire !

I'm sure glad I don't have to know all that stuff^ to grow good bud. I'd be smokeless lol... Good of you to keep things real OG bub. Don't feel bad;if your right, your right.... Imo if your going to try and teach somebody something you better know what your talking about...lol just look at p4p enough said eh? take care...BC

 

[3legdog]

Bubs 1 cool kat & those OD pic's look great. Peace all 3ld

 

[ndnguy]

Can I roll around in your OD patch bro??? I remember that post by P4P about how he knew this and that because of the terpenes, and I think he actually said from bubble hash LMFAO , till BUB caught him bigtime and no big words were going to get him out of that one LOL , great job bro....ndn

 

[OG bub]

was glad to hear from guineapig today. I dont think he had any ill intent, mabey just a misunderstanding.
was good to talk to him.

Peace folks!

oh and ndnguy, you can only roll in the manacured buds

bub.

 

[guineapig]

yes everything is fine.....i just wanted to delete that post due to inaccuracies....

 

[Gamera]

gp-if you start a thread you can't delete the 1st post, only admin.

 

[guineapig]

oh boy- i made a big mistake, then.....i'm sorry everyone....-gp