Green fluorescent protein (GFP) as a reporter gene for the plant pathogenic oomycete Phytophthora palmivora

Transgenic Phytophthora palmivora strains that produce green fluorescent pr otein (GFP) or beta-glucuronidase (GUS) constitutively were obtained after stable DNA integration using a polyethylene-glycol and CaCl2-based transfor mation protocol. GFP and GUS production were monitored during several stage s of the life cycle of P. palmivora to evaluate their use in molecular and physiological studies, 40% of the GFP transformants produced the GFP to a l evel detectable by a confocal laser scanning microscope, whereas 75% of the GUS transformants produced GUS. GFP could be visualised readily in swimmin g zoospores and other developmental stages of P. palmivora cells. For high magnification microscopic studies, GFP is better visualised and was superio r to GUS. In contrast, for macroscopic examination, GUS was superior. Our f indings indicate that both GFP and GUS call be used successfully as reporte r genes in P. palmivora. (C) 1999 Federation of European Microbiological So cieties. Published by Elsevier Science B.V. All rights reserved.