title: Evolution and structural diversification of Nictaba-like lectin genes in food crops with a focus on soybean (Glycine max).
abstract: The Nictaba family groups all proteins that show homology to Nictaba, the tobacco lectin. So far, Nictaba and an Arabidopsis thaliana homologue have been shown to be implicated in the plant stress response. The availability of more than 50 sequenced plant genomes provided the opportunity for a genome-wide identification of Nictaba -like genes in 15 species, representing members of the Fabaceae, Poaceae, Solanaceae, Musaceae, Arecaceae, Malvaceae and Rubiaceae. Additionally, phylogenetic relationships between the different species were explored. Furthermore, this study included domain organization analysis, searching for orthologous genes in the legume family and transcript profiling of the Nictaba -like lectin genes in soybean.
  
  
  
  Using a combination of BLASTp, InterPro analysis and hidden Markov models, the genomes of Medicago truncatula , Cicer arietinum , Lotus japonicus , Glycine max , Cajanus cajan , Phaseolus vulgaris , Theobroma cacao , Solanum lycopersicum , Solanum tuberosum , Coffea canephora , Oryza sativa , Zea mays, Sorghum bicolor , Musa acuminata and Elaeis guineensis were searched for Nictaba -like genes. Phylogenetic analysis was performed using RAxML and additional protein domains in the Nictaba-like sequences were identified using InterPro. Expression analysis of the soybean Nictaba -like genes was investigated using microarray data.
  
  
  
  Nictaba -like genes were identified in all studied species and analysis of the duplication events demonstrated that both tandem and segmental duplication contributed to the expansion of the Nictaba gene family in angiosperms. The single-domain Nictaba protein and the multi-domain F-box Nictaba architectures are ubiquitous among all analysed species and microarray analysis revealed differential expression patterns for all soybean Nictaba-like genes.
  
  
  
  Taken together, the comparative genomics data contributes to our understanding of the Nictaba -like gene family in species for which the occurrence of Nictaba domains had not yet been investigated. Given the ubiquitous nature of these genes, they have probably acquired new functions over time and are expected to take on various roles in plant development and defence.
authors.affiliation: Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Van Holle
authors.affiliation: UMR 152 PHARMA-DEV, Université de Toulouse, IRD, UPS, Chemin des Maraîchers 35, 31400 Toulouse, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Rougé
authors.affiliation: Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Els J M
authors.initials: EJM
authors.lastname: Van Damme
mesh_terms: D018556:Crops, Agricultural / Q000235:genetics* / Q000378:metabolism; D037102:Lectins / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism
chemical_list: D037102:Lectins; D010940:Plant Proteins
keywords: Glycine max; Lectin; Nictaba; comparative genomics; duplication; evolution; food crop; legume; phylogeny