Elicitation of the Hypersensitive Responses in Tabacco by a10.6 kD Proteinaceous Elicitor from Phytophthora palmi Expression and Biological Assay of HrpN in Pichia pastoris Elicitin-plant interaction and signal transduction of defense reaction Elicitation on Artemisinin Biosynthesis in Artemisia annua Hairy Roots by the Oligosaccharide Extract from the Endophytic Colletotrichumsp. B501