Studies of tissue colonization in Rhododendron by Phytophthora ramorum

Abstract

The knowledge on latency is of great importance to prevent the spread of Phytophthora ramorum with healthy looking plant material. To learn more about the tissue colonisation in Rhododendron, histological studies with epifluorescence microscopy have been started. Epifluorescence images showing P. ramorum structures in different tissues are presented. A first idea of P. ramorum development in Rhododendron root, twig and leaf tissue is offered for discussion. To improve and simplify the specific detection of P. ramorum structures under controlled conditions a method for the genetic transformation of P. ramorum with the reporter gene for Green Fluorescent Protein (GFP) was developed. With protoplast transformation transgenic P. ramorum strains could be produced for the first time. Integration of the transferred genes was proved by RT-PCR. Expression of the marker gene nptII could be verified by growth of transformed strains on medium containing antibiotics (geneticin). Expression of the GFP gene in hyphae, zoosporangia, germinating cysts and clamydospores could be demonstrated with a confocal laser scanning microscope (CLSM).

Parent Publication

• Proceedings of the sudden oak death third science symposium

Citation

Riedel, Marko; Wagner, Stefan; Götz, Monika; Belbahri, Lassaad; Lefort, Francois; Werres, Sabine. 2008. Studies of tissue colonization in Rhododendron by Phytophthora ramorum. In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 485-487