Secondary metabolism, evolution

An attractive hypothesis is the independent evolution in bacteria of their diffusible individualites and the currently recognized secondary metabolic pathways, in parallel with their surface components and their biosynthesis. An indicator for this would be the use of the same gene pool. The theory would include all substances that play a role in the build-up of glycan and other modified surface layers, lipids, murein, (glyco-) proteins (e.g., S-layers), polysaccharides, teichoic... 

Wink, M. and Mohamed, G. 1. A. 2003. Evolution of chemical defense traits in the Leguminosae Mapping of distribution patterns of secondary metabolities on a molecular phylogeny inferred from nucleotide sequences of the rbcL gene. Biochemical Systematics and Ecology, 31 8 897-917. 

Wink, M. 2003. Evolution of secondary metabolities from an ecological and molecular phylogenetic perspective. Phytochemistry, 64 1 3-19. 

Vogt, T., Glycosyltransferases involved in plant secondary metabolism, in Evolution of Metabolic Pathways, Romeo, J.T., Ibrahim, R., Varin, L., and De Luca, V., Eds., Elsevier Science, Oxford, 2002, 317. 

In biology, many long held categorisations were finally abandoned because they were no longer productive, meaningful or they lacked an adequate evolutionary underpinning. The model for the evolution of metabolism outlined in this chapter explains why the terms primary metabolism and secondary metabolism should now be consigned to history. 

Zahner H, Ankle H, Ankle T. (1983). Evolution and secondary pathways. In JW Benett, A Ciegler (Eds.), Secondary metabolism and differentiation in fungi (pp. 153-175). Marcel Bekker, New York. 

Tenser T, Gee DR. [2005). Modelling the evolution of secondary metabolic pathways. University of York, MPhil Project Report Abstract). Plants and microbes invest heavily in producing chemicals termed Natural Products. These chemicals are produced in secondary metabolic pathways. In this report, we develop a model for the evolution of secondary pathways, and investigate what factors are important in aUowing these pathways to arise and persist. The results imply that certain mutation rates are important in generating chemical diversity, and we give conditions on these for optimal fitness in a population. We also find that the rate of competitive evolution and the chances that new compounds have to be beneficial or harmful are important factors. 

ST. PIERRE, B., DE LUCA, V., Evolution of acyltransferase genes Origin and diversification of the BAHD suprfamily of acyltransferases involved in secondary metabolism, in Evolution of Metabolic Pathways Rec. Adv. Phytochemistry Vol. 34 (J.T. Romeo, R.K. Ibrahim, L. Varin, V. De Luca, eds.), Pergamon Press, Amsterdam. 2000, pp.285-315. 

Wink, M. (2008a) Plant secondary metabolism diversity, function and its evolution. Nat. Prod. Commun., 3,1205-16. 

CHEMOTAXONOMY SEEN FROM A PHYLOGENETIC PERSPECTIVE AND EVOLUTION OF SECONDARY METABOLISM... 

This chapter discusses the history and present state of chemotaxonomy in view of our knowledge of the molecular phylogeny of plants. In the second part of this chapter, the possible evolution of secondary metabolism will be elaborated (for a review, see Wink, 2003, 2007). This analysis helps to understand the discrepancies between chemotaxonomy and molecular phylogeny (for a review, see Wink, 2008). 

One of the main questions discussed in this chapter is about the origin and evolution of plant secondary metabolism. We have started with the observation that some SM (such as phenolics and terpenoids) are produced by nearly all vascular plants, whereas others, especially those with alkaloids, cardiac glycosides, anthraquinones, etc., show a more restricted but usually patchy distribution. 

The emergence of further streptomycete genomes will add to our understanding of CYP evolution, and the numbers of CYPs in unknown pathways of secondary metabolism will reveal new natural products. Given the estimate that only 1% of microorganisms are culturable, the depth of the biocatalytic reservoir of CYPs becomes evident. The reason why the streptomycetes and mycobacteria have many CYPs is not clear, as other soil bacteria contain either small numbers of CYPs (Table 13.1) or none. 

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