title: Coffee (Coffea arabica L.) genes early expressed during infection by the rust fungus (Hemileia vastatrix).
abstract: SUMMARY The beverage cash crop coffee (Coffea arabica L.) is subject to severe losses caused by the rust fungus Hemileia vastatrix. In naturally resistant coffee plants, a specific hypersensitive reaction (HR) may be elicited early to stop fungal infection. To isolate host genes involved in HR, we undertook an expressed sequence tags (ESTs) analysis. Two cDNA libraries were constructed using suppression subtractive hybridization (SSH) and 527 non-redundant ESTs were generated from 784 randomly picked clones. Classification of the ESTs into several functional categories showed that more than one-quarter of the predicted proteins might encode disease resistance (R) proteins, stress- and defence-proteins, and components of signal transduction pathways. Twenty-eight differentially screened sequences (DSSs) were selected after differential hybridization of 1000 cDNA clones from each library. Investigation of the expression patterns of a subset of 13 DSSs showed higher levels of gene expression in inoculated plants compared with control plants. HR-up-regulation of transcript accumulation occurred for 9 out of the 13 genes 24 and 48 h after H. vastatrix challenge. Two genes encoded homologues of the Arabidopsis DND1 and NDR1 proteins, suggesting conservation of resistance signalling pathways in perennial plants. Other HR-regulated sequences matched receptor kinases, AP2 domain- and WRKY transcription factors, cytochromes P450, heat shock 70 proteins, glucosyltransferases and proteins of unknown function. The ESTs reported here provide a useful resource for studying coffee resistance responses and for improving C. arabica for durable disease resistance.
authors.affiliation: Institut de Recherche pour le Développement (IRD), UMR 1097 Diversité et Génome des Plantes Cultivées, Equipe Résistance des Plantes, 911 avenue Agropolis, BP64501, 34394 Montpellier Cedex 5, France.
authors.forename: Diana
authors.initials: D
authors.lastname: Fernandez
authors.forename: Patricia
authors.initials: P
authors.lastname: Santos
authors.forename: Caroline
authors.initials: C
authors.lastname: Agostini
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Bon
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Petitot
authors.forename: Maria
authors.initials: M
authors.lastname: C Silva
authors.forename: Leonor
authors.initials: L
authors.lastname: Guerra-Guimarães
authors.forename: Ana
authors.initials: A
authors.lastname: Ribeiro
authors.forename: Xavier
authors.initials: X
authors.lastname: Argout
authors.forename: Michel
authors.initials: M
authors.lastname: Nicole