First touch: An immediate response to surface recognition in conidia of Blumeria graminis

Conidia of the plant pathogen Blumeria graminis recognize and respond to fe atures of certain substrata. Appropriate surfaces induce release of an extr acellular proteinaceous matrix from the body of the conidium. Contact with a hydrophobic substratum elicits almost immediate release of the matrix at the contact interface. In this investigation we present, for the first time , evidence that recognition of the substratum by conidia can stimulate upta ke of anionic, low-molecular-weight materials before germination. This faci litated transport could be a mechanism for recognition of the host and dete rmination of the direction of growth of the emerging germ tube toward the h ost leaf surface. (C) 2000 Academic Press.