Abstract: Luciferase labeling is a powerful tool for tracing dynamic activity of microorganisms in the ecosystem.Experiments were conducted with DLL-1 that was labeled with luxAB to investigate distribution of the pesticide-degrading bacterium in soil and its invasion into roots.Luminescence could be detected even 30 days after labeling.The roots were dissected and cultured on plate for 24 hours and then exposed to X-ray film.Results also showed that the strain could invade into root of the plant.Parathion hydrolysis and plasmids detection also verified colonization and invasion of the bacteria of the strain.

Key words: pesticide, parathion-methyl, degrading bacterium, Pseudomonas sp.DLL-1, luxAB, molecular labeling, colonization