title: Large-scale analysis of NBS domain-encoding resistance gene analogs in Triticeae.
abstract: Proteins containing nucleotide binding sites (NBS) encoded by plant resistance genes play an important role in the response of plants to a wide array of pathogens. In this paper, an in silico search was conducted in order to identify and characterize members of NBS-encoding gene family in the tribe of Triticeae. A final dataset of 199 sequences was obtained by four search methods. Motif analysis confirmed the general structural organization of the NBS domain in cereals, characterized by the presence of the six commonly conserved motifs: P-loop, RNBS-A, Kinase-2, Kinase-3a, RNBS-C and GLPL. We revealed the existence of 11 distinct distribution patterns of these motifs along the NBS domain. Four additional conserved motifs were shown to be significantly present in all 199 sequences. Phylogenetic analyses, based on genetic distance and parsimony, revealed a significant overlap between Triticeae sequences and Coiled coil-Nucleotide binding site-Leucine rich repeat (CNL)-type functional genes from monocotyledons. Furthermore, several Triticeae sequences belonged to clades containing functional homologs from non Triticeae species, which has allowed for these sequences to be functionally assigned. The findings reported, in this study, will provide a strong groundwork for the isolation of candidate R-genes in Triticeae crops and the understanding of their evolution.
authors.affiliation: Unité de Recherche Génomique des Insectes Ravageurs des Cultures d'Intérêt Agronomique , Faculté des Sciences de Tunis, Université de Tunis El Manar , El Manar, Tunis , Tunisia . ; Institut Supérieur de Biotechnologie de Béja , Université de Jendouba , Béja , Tunisia .
authors.forename: Dhia
authors.initials: D
authors.lastname: Bouktila
authors.affiliation: Unité de Recherche Génomique des Insectes Ravageurs des Cultures d'Intérêt Agronomique , Faculté des Sciences de Tunis, Université de Tunis El Manar , El Manar, Tunis , Tunisia .
authors.forename: Yosra
authors.initials: Y
authors.lastname: Khalfallah
authors.affiliation: Unité de Recherche Génomique des Insectes Ravageurs des Cultures d'Intérêt Agronomique , Faculté des Sciences de Tunis, Université de Tunis El Manar , El Manar, Tunis , Tunisia .
authors.forename: Yosra
authors.initials: Y
authors.lastname: Habachi-Houimli
authors.affiliation: Unité de Recherche Génomique des Insectes Ravageurs des Cultures d'Intérêt Agronomique , Faculté des Sciences de Tunis, Université de Tunis El Manar , El Manar, Tunis , Tunisia .
authors.forename: Maha
authors.initials: M
authors.lastname: Mezghani-Khemakhem
authors.affiliation: Unité de Recherche Génomique des Insectes Ravageurs des Cultures d'Intérêt Agronomique , Faculté des Sciences de Tunis, Université de Tunis El Manar , El Manar, Tunis , Tunisia .
authors.forename: Mohamed
authors.initials: M
authors.lastname: Makni
authors.affiliation: Unité de Recherche Génomique des Insectes Ravageurs des Cultures d'Intérêt Agronomique , Faculté des Sciences de Tunis, Université de Tunis El Manar , El Manar, Tunis , Tunisia . ; Institut Supérieur de l'Animation pour la Jeunesse et la Culture , Université de Tunis , Bir-El-Bey , Tunisia .
authors.forename: Hanem
authors.initials: H
authors.lastname: Makni
keywords: NBS domain; Triticeae; data mining; phylogeny; plant resistance genes