Abstract: By the method of nutrient solution cultivation, this paper studied the effects of pathogens infection on the root exudates collections at the early growth stage of Panax ginseng. In the collections of the control and the treatments infected with Sclerotinia schinseng, Phytophthora cactorum, Rhizoctonia solani, and Cylindrocarpon destructans, 27, 23, 17, 16, and 20 principal components were detected, and 11, 6, 6, 3, and 9 of them were validated with standards, respectively. The results showed that under the effects of pathogens infection, the number of principal components in Panax ginseng root exudates collections decreased significantly, and the kinds of the compounds varied evidently. The newly produced compounds were mainly of organic esters, benzoic and phenolic derivatives, while the disappeared compounds were miscellaneous.

Key words: Molecular responses, mRNA differential display, Oryza sativa L., UV-B radiation