A typical character of plants is the production and storage of usually complex mixtures of secondary metabolites (SM). The main function of secondary metabolites is defense against herbivores and microbes; some SM are signal compounds to attract pollinating and seed dispersing animals or play a role in the symbiotic relationships with plants and microbes. The distribution of SM in the plant kingdom shows an interesting pattern. A specific SM is often confined to a particular systematic unit, but isolated occurrences can occur in widely unrelated taxonomic groups. This review tries to explain the patchy occurrence of SM in plants. It could be due to convergent evolution, but evidence is provided that the genes that encode the biosynthesis of SM appear to have a much wider distribution than the actual secondary metabolite. It seems to be rather a matter of differential gene regulation whether a pathway is active and expressed in a given taxonomic unit or not. It is speculated that the genes of some pathways derived from an early horizontal gene transfer from bacteria, which later became mitochondria and chloroplasts. These genes/pathways should be present in most if not all land plants. About 80% of plants live in close symbiotic relationships with symbiotic fungi (ectomycorrhiza, endophytes). Recent evidence is presented that these fungi can either directly produce SM, which were formerly considered as plant SM or that these fungi have transferred the corresponding pathway gene to the host plant. The fungal contribution could also explain part of the patchy occurrence patterns of several secondary metabolites.
HarborneJB, BaxterH. (1993) Phytochemical Dictionary. A Handbook of Bioactive Compounds from Plants. Taylor & Francis, London; HarborneJB, TurnerBL. (1984) Plant Chemosystematics. Academic Press, London.
10.
DNP (1996) Dictionary of Natural Products on CD-Rom version 5:1, Chapman & Hall, London.
11.
WinkM. (2003) Evolution of secondary metabolites from an ecological and molecular phylogenetic perspective. Phytochemistry64, 3–19.
12.
StahlE. (1888) Pflanzen und Schnecken. Jenaische Zeitschrift für Naturwissenschaften, 22, 557–684.
13.
WinkM. (1988) Plant breeding: Importance of plant secondary metabolites for protection against pathogens and herbivores. Theoretical and Applied Genetics, 75, 225–233.
14.
WinkM. (1999) Function of plant secondary metabolites and their exploitation in biotechnology. Annual Plant Reviews Vol. 3, Sheffield Academic Press, Sheffield.
15.
LevinDA. (1976) The chemical defences of plants to pathogens and herbivores. Annual Review of Ecology and Systematics, 7, 121–159.
16.
SwainT. (1977) Secondary compounds as protective agents. Annual Review of Plant Physiology, 28, 479–501.
17.
RosenthalGA, BerenbaumMR. (1991) Herbivores: Their Interactions with Secondary Plant Metabolites. Vol. 1, The chemical participants; Academic press, San Diego; RosenthalGA, BerenbaumMR (1992): Herbivores: Their interactions with secondary plant metabolites. Vol. 2. Ecological and evolutionary processes. Academic press, San Diego.
18.
BernaysEA, ChapmanRF. (1994) Host-Plant Selection by Phytophagous Insects. Chapman and Hall, London.
19.
WinkM. (1992) The role of quinolizidine alkaloids in plant insect interactions. In Insect- Plant Interactions.BernaysEA. (Ed.), Vol. IV, 133–169, CRC-Press, Boca Raton.
20.
WinkM. (1985) Chemische verteidigung der lupinen: zur biologischen bedeutung der chinolizidinalkaloide. Plant Systematics and Evolution, 150, 65–81.
DoyleJJ. (1993) DNA, phylogeny, and the flowering of plant systematics. Bio Science, 43, 380–389.
24.
APG II (2003) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society, 141, 399–436.
25.
WinkM, WatermanP. (1999) Chemotaxonomy in relation to molecular phylogeny of plants. In Biochemistry of Plant Secondary Metabolism. WinkM. (Ed.), Sheffield Academic Press, Annual Plant Reviews, Vol. 2, pp 300–341.
26.
RobertsMF, WinkM. (1998) Alkaloids-Biochemistry, Ecological Functions and Medical Applications. Plenum, New York.; KutchanTM (1995) Alkaloid biosynthesis: the basis for metabolic engineering of medicinal plants. The Plant Cell, 7, 1959–1970.
27.
WinkM. (2000) Interference of alkaloids with neuroreceptors and ion channels. In Bioactive Natural Products. Vol. 11, Atta-ur-Rahman (Ed.), Elsevier. pp. 3–129.
28.
WinkM, WitteL. (1983) Evidence for a wide spread occurrence of the genes of quinolizidine alkaloid biosynthesis. Induction of alkaloid accumulation in cell suspension cultures of alkaloid-“free” species. FEBS letters, 159, 196–200.
29.
WinkM, MohamedGIA. (2003) Evolution of chemical defence traits in the Leguminosae: Mapping of distribution patterns of secondary metabolites on a molecular phylogeny inferred from nucleotide sequences of the rbcL gene. Biochemical Systematics and Ecology, 31, 897–917.
30.
BoatwrightJS, le RouxMM, WinkM, MorozovaT, van WykB-E. (2008) Systematics of the tribe Crotalarieae (Fabaceae). American Journal of Botany (submitted)
31.
WinkC, HartmannT (1981) Properties and subcellular localisation of L-alanine: aldehyde aminotransferase. Concept of an ubiquitous plant enzyme involved in secondary metabolism. Zeitschrift für Naturforschung, 36c, 625–632.
32.
WinkM, HartmannT. (1982) Localization of the enzymes of quinolizidine alkaloid biosynthesis in leaf chloroplast of Lupinus polyphyllus. Plant Physiology, 70, 74–77.
33.
RobertsMF. (1981) Enzymic synthesis of coniceine in Conium maculatum chloroplasts and mitochondria. Plant Cell Reports, 1, 10–13.
34.
RemyW, TaylorTN, HassH, KerpH (1994) Four hundred-million-year-old vesicular arbuscular mycorrhizae. Proceedings National Academy of Sciences, USA, 91, 11841–11843.
35.
SimonL, BousquetJ, LevesqueC, LalondeM. (1993) Origin and diversification of endomycorrhizal fungi and coinidence with vascular land plants. Nature, 263, 67–69.
36.
SawersRJH, GutjahrC, PaszkowskiU. (2008) Cereal mycorrhiza: an ancient symbiosis in modern agriculture. Trends Plant Science, 13, 93–97.
LehtonenP, HelanderM, WinkM, SporerF, SaikkonenK. (2005) Transfer of endophyte origin defensive alkaloids from a grass to hemiparasitic plant. Ecology letters, 8, 1256–1263.
39.
RalphsMH, CreamerR, BaucomD, GardnerDR, WelshSL, GrahamJD, HartC, CookD, StegelmeierBL. (2008) Relationship between the endophyte Embellisia spp. and the toxic alkalod swainsonine in major locoweed species (Astragalus and Oxytropis). Journal of Chemical Ecology, 34, 32–38.
40.
CassadyJM, ChanKK, FlossH, LeistnerE. (2004) Recent developments in the maytansinoid antitumor agents. Chemistry, Pharmacy Bulletin, 52, 1–26.
41.
KusariS, LamshöftM, ZühlkeS, SpitellerM. (2008) An endophytic fungus from Hypericum perforatum that produces hypericin. Journal of Natural Products, 71, 159–162.
42.
PuriSC, VermaV, AmnaT, QaziGN, SpitellerM. (2005) An endophytic fungus from Nothapodytes foetida that produces camptothecin. Journal of Natural Products, 68, 1717–1719.
43.
StierleA, StrobelG, StierleD. (1993) Taxol and taxane production by Taxomyces andreanae, an endophytic fungus of Pacific yewScience, 260, 214–216.
44.
OttagggioL, BestosoF, AmirottiA, BalbiA, DamonteG, MazzeiM, SancandiM, MieleM. (2008) Taxanes from shells and leaves of Corylus avellana. Journal of Natural Products, 71, 58–60.
45.
EybergerAL, DondapatiR, PorterJRJ. (2006) Endophyte fungal isolates from Podophyllum peltatum produce podophyllotoxin. Journal of Natural Products, 69, 1121–1124.
46.
WinkM, BotschenF, GosmannC, SchäferH, WatermanPG. (2008) Evolution and origin of plant secondary metabolism-Implications for chemotaxonomy. In Wink M. Biochemistry of plant secondary metabolism. Blackwell-Wiley-VCH (in press).
