Recent Progress of the Research on Toxins Produced by Species of Seiridium Associated with Cypress Canker Diseases : Shoot and Foliage Diseases in Forest Trees. Proceedings of a Joint Meeting of the Working Parties Canker and Shoot Blight of Conifers (S2.06.02) Foliage Diseases (S2.06.04)

Florenz

1995

S. 126-136

17 Lit. Ang.

Bandaufführung

13577

77403

Seiridium cardinale, Seiridium cupressi and Seiridium unicorne, three species of fungi associated with canker diseases of cypress, produce several phytotoxins in culuture. These compounds were identified as butenolides (seiridins), four cyclic sesquiterpenes (seiricardines), one 14-macrolide (seiricuprolide) and one aromatic ortho-dialdehyde acid). Seiridin and seiricardines B and C induced hypertrophic reaction of cortical tissues of C. macrocarpa. Seiridin and cyclopaldic acid caused losses of electrolytes from shoot tissues of C. macrocarpa and to a greater extent from shoots of C. sempervirens or C. arizonica. The addition of 50 MyM seiridin to the culture medium produced a hormone-like effect on callus tissues or cell suspension cultures of C. macrocarpa and C. arizonica. Seiridin affected also root growth of herbaceous test plants. All the above phytotoxins were nonselective and induced symptoms on host plants which were very reminiscent of those shown by naturally infected cypress trees. Studies on structure-activity relationship of seiridins and cyclopaldic acid was carried out with a series of derivatives. The results indicated that the bioactivity of seiridin is related to the hydroxy group of the side chain and to the Gamma-lactone ring, whereas that of cyclopaldic acid is related to the presence of at least one of two aldehyde groups. Furthermore, seiridin showed to have antimicrobial activity on bacteria, whereas cyclopaldic acid or seiricardines elicited antifungal activity.