Bakteriološka sekcija: predavanje prof. dr. Hildgund Schrempf

Bakteriološka sekcija HMDa i PBF Sveučilišta u Zagrebu, organiziraju predavanje:

Biocontrol of fungi on plants by streptomycetes

Prof. Hildgund Schrempf (Osnabrueck, SR Njemačka)

U četvrtak, 21.04.2011. u 10,30 h

na PBF-u, Pierottijeva 6, I kat, predavaona 4

Our investigations revealed that streptomycetes produce -in addition to secondary metabolites- a large repertoire of novel proteins, which contribute to inhibit the growth of certain fungi. Based on these findings, we hypothesized a possible concerted interaction of Streptomyces strain(s) with the fungal plant pathogen Verticillium dahliae. This filamentous fungus causes worldwide the vascular wilt of over 200 dicotyledonous plant species including important field and horticultural crops, flowers and tree species. Due to the absence of specific, and approved fungicides against V. dahliae, and the low-level resistance of the cultivars against this pathogen, losses are immense. We found that Streptomyces lividans strongly reduces the germination of V. dahliae conidia, the subsequent growth of hyphae as well as their differentiation to conidia and microsclerotia, which survive harsh conditions. Plants (Arabidopsis thaliana), which arise in the presence of V. dahliae within agar or soil, have damaged root cells, an atrophied stem and root, as well as poorly developed leaves with chlorosis symptoms. In contrast, S. lividans hyphae settle in bunches preferentially at the outer layer near tips and alongside roots. Resulting plants have a healthy appearance including an intact root system. A. thaliana seeds, which are co-inoculated with V. dahliae and S. lividans, have preferentially proliferating bacterial hyphae within the seed-mucilage and at roots of the outgrowing seedlings. As a result, plants have considerably reduced disease symptoms. As spores of the beneficial S. lividans strain are obtainable in large quantity, its application in biocontrol is discussed.

Za HMD dr. Jasenka Pigac

Za PBF prof. dr. Vladimir Mrša