Tissue-Specific and Development-Dependent Accumulation of Phenylpropanoids in Larch Mycorrhizas.

The tissue-specific and development-dependent accumulation of secondary products in roots and mycorrhizas of larch (Larix decidua Mill.; Pinaceae) was studied using high-performance liquid chromatography and histochemical methods. The compounds identified were soluble catechin, epicatechin, quercetin 3-O-[alpha]-rhamnoside, cyanidin- and peonidin 3-O-[beta]-glucoside, 4-O-[beta]-hydroxybenzoyl-O-[beta]-glucose, 4-hydroxybenzoate 4-O-[beta]-glucoside, maltol 3-O-[beta]-glucoside, and the wall-bound 4-hydroxybenzaldehyde, vanillin, and ferulate.

Levels of a terpenoid glycoside (blumenin) and cell wall-bound phenolics in some cereal mycorrhizas.

Four cereals, Hordeum vulgare (barley), Triticum aestivum (wheat), Secale cereal (rye), and Avena sativa (oat), were grown in a defined nutritional medium with and without the arbuscular mycorrhizal fungus Glomus intraradices. Levels of soluble and cell wall-bound secondary metabolites in the roots of mycorrhizal and nonmycorrhizal plants were determined by high-performance liquid chromatography during the first 6 to 8 weeks of plant development. Whereas there was no difference in the levels of the cell wall-bound hydroxycinnamic acids, 4-coumaric and ferulic acids, there was a fungus-induced change of the soluble secondary root metabolites.

Secondary fungal metabolites and their biological activities, V. Investigations concerning the induction of the biosynthesis of toxic secondary metabolites in basidiomycetes.

In cultures of the basidiomycetes Heterobasidion annosum, Gloeophyllum abietinum or Armillaria ostoyae, the biosynthesis of some of their toxic secondary metabolites is enhanced up to 400-fold when they grow in the presence of an antagonist. This stimulation is induced before any cell contact occurs. The "inducing signals" are not macromolecules, polypeptides or constituents of the cell membranes, but the same toxins which are synthesized already in monocultures in very low concentrations.

Secondary fungal metabolites and their biological activities, III. Further metabolites from dual cultures of the antagonistic basidiomycetes Heterobasidion annosum and Gloeophyllum abietinum.

In addition to a preceding publication (Sonnenbichler, J., Bliestle, I.M.

Secondary fungal metabolites and their biological activities, II. Occurrence of antibiotic compounds in cultures of Armillaria ostoyae growing in the presence of an antagonistic fungus or host plant cells.

We found that in the presence of host plant cells or some antagonistic fungi, the highly forest-pathogenic basidiomycete Armillaria ostoyae is strongly stimulated to produce a series of toxic secondary metabolites which are capable of inhibiting the growth of the antagonist or of killing the plant cells still before cell contact. The chemical structures of the metabolites have been identified, of which two of them are new compounds. The time dependence and sites of synthesis in the mycelium have been determined in order to lay the foundation for future studies concerning the induction mechanism for the synthesis of the toxins.