Lysergyl peptide synthetase from the Convolvulaceae?

[Fractalhead]

I understand that when ergot alkaloids were first identified in morning glory seeds by Hofmann that there was much suspicion by the scientific community that some kind of fungal endophyte or fungal contamination of seed samples must have been responsible for the biosynthesis of the compounds since ergot alkaloids had only been found in fungi at the time. I vaguely remember reading that this controversy had been cleaned up by some kind of study that 'proved' that the compounds were indeed made by the plant. So does anyone know the details of this study? I did a quick search on pubmed and couldn't find anything and i can't remember where i read about the study.

I recently attended a seminar in which the speaker said that lysergyl peptide synthetase (lps) enzymes are only known to occur in fungi and bacteria but not plants. These enzymes catalyse the formation of the amide bonds of various lysergic amides in endophytic fungi. Interestingly, a recent knockout experiment showed that ergine production is eliminated in Neotyphodium lolii when the lps1 gene is knocked out suggesting that this enzyme may be responsible for ergine synthesis or a step leading to its synthesis. It would be very interesting to probe Argyreia or Ipomoea genomic DNA for a homologous gene since if some plants do indeed contain lps genes, this would be of great evolutionary significance. Hmmm... I wonder how fussy the lps enzymes are when it comes to substrates?

[2b]

Found this in Erowid, not quite sure if it is the awnser your were looking for but the references supplied should be a good start.

The discovery of ergot alkaloids in ololiuqui i.e. in R. corymbosa and I. violacea was quite unexpected and of particular interest from the phytochemical point of view because lysergic acid alkaloids, which had hitherto been isolated only from the lower fungi of the genus Claviceps, Penicillium, or Rhizopus, were now, for the first time, found in higher plants, in the phanerogamic family Convolvulaceae. Subsequent chemical investigations in various other laboratories confirmed the occurrence of ergot alkaloids in lpomoea species ([51] , [52] , [53] , [54] , [55] , [56] ).

051

W. A. Taber and R. A. Heacock, Can. J. Microbiol. 8, 137 (1962).

052

W. A. Taber, L. C. Vining and R. A. Heacock, Phytochemistry 2, 65 (1963).

053

D. Gröger, Flora, 153, 373 (1963).

054

W. A. Taber, R. A. Heacock and M. E. Mahon, Phytochemistry 2, 99 (1963).

055

H. C. Beyermann, A. van de Linde and G. J. Henning, Chem. Weekblad 59, 508 (1963).

056

J. W. Hylin and D. P. Watson, Science 148, 499 (1965).

[Fractalhead]

Cool. So phytochemical studies confirmed that these alkaloids occur in these plants but I guess I'll have to read the refs to find out how they ruled out an endophytic fungus. Interestingly, some convolvulaceous species also contain the lolitrem class alkaloids that occur in A. lolii infected ryegrass. The funny thing is that these alkaloids, while being derived from tryptophan, require a completely different set of genes to the ergoline alkaloids. The independent co-evolution of both alkaloid classes in the plant genome seems unlikely. Perhaps the alkaloids are indeed made by an endosymbiotic fungus? Or perhaps the plants obtained the ability to make these products by some crazy lateral gene transfer process?

[2b]

Fractalhead , not sure if you have already seen this link.I posted it in the mycology thread but didn't get any takers.Sounds like it could be up your alley as it does mention The Oz varietes and how they arrived here

Evolution of Claviceps PDF

Interestingly it goes on about habitat association ( claviceps purpurea ) recently discovered in an insect pathogen Metarrhizium anisopliae (Bidochka et al 2001)