Canadian Journal of Botany - Revue Canadienne de Botanique (1995) 73, S609-S615

Ralph L. Nicholson and Hitoshi Kunoh (1995)
Early interactions, adhesion, and establishment of the infection court by Erysiphe graminis
Canadian Journal of Botany - Revue Canadienne de Botanique 73 (S1), S609-S615
Abstract: The establishment of a fungal pathogen on the surface of its host is essential to the success of the infection process. For many fungi, establishment on the host is an active process that may depend on recognition of the host surface through chemical or topographic signals. Events that allow for establishment may be considered to represent the 'preparation of the infection court' by the pathogen. This sometimes involves the adhesion of the pathogen to the host and possibly the alteration of the host's surface topography or chemistry. Adhesion is often presumed to be a single, chemically mediated event associated with germ tube or appressorium formation. However, adhesion of ungerminated propagules may also occur, and evidence suggests that it is mediated by the release of adhesive materials directly from the propagule upon contact with a suitable substratum. Fungi may require either a hydrophobic or a hydrophilic surface to initiate the infection process. The barley powdery mildew pathogen, Erysiphe graminis, requires a hydrophilic surface for appressorium formation, yet the barley leaf is extremely hydrophobic. The problem is resolved by the release of an exudate from conidia that makes the hydrophobic leaf surface hydrophilic. In contrast, Colletotrichum graminicola requires a hydrophobic surface for the initiation of its infection process. Ungerminated conidia of this fungus release materials that allow for the rapid adhesion of conidia, which ensures that germination and appressorium formation occur, initiating the infection process. For both fungi, these events happen well in advance of germination and establish the pathogen at the site of the infection court.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Hitoshi Kunoh, Ralph L. Nicholson

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Blumeria graminis
	Colletotrichum graminicola