title: Broad screening of the legume family for variability in seed insecticidal activities and for the occurrence of the A1b-like knottin peptide entomotoxins.
abstract: Pea albumin 1b (PA1b) is a small sulphur-rich peptide from pea seeds, also named leginsulin because of the binding characteristics of its soybean orthologue. Its insecticidal properties were discovered more recently. By using a combination of molecular, biochemical and specific insect bioassays on seed extracts, we characterised genes from numerous Papilionoideae, but not from Caesalpinioideae or Mimosoideae, although the last group harboured species with partially positive cues (homologous biological activities). The A1b defence peptide family, therefore, appears to have evolved relatively late in the legume lineage, maybe from the sophoroid group (e.g. Styphnolobium japonicum). However, unambiguous sequence information is restricted to a group of tribes within the subfamily Papilionoideae (Psoraleae, Millettieae, Desmodieae, Hedysareae, Phaseoleae, Vicieae, and the now clearly polyphyletic "Trifolieae" and "Galegeae"). Recent diversification by gene duplications has occurred in many species, or longer ago in some lineages (Medicago truncatula), as well as probable gene or expression losses at different taxonomic levels (Loteae, Vigna subterranea).
authors.affiliation: UMR203 BF2I (Biologie Fonctionnelle Insectes et Interactions), IFR41, INRA, INSA-Lyon, F-69621 Villeurbanne, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Louis
authors.forename: Bernard
authors.initials: B
authors.lastname: Delobel
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gressent
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Duport
authors.forename: Ousmane
authors.initials: O
authors.lastname: Diol
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rahioui
authors.forename: Hubert
authors.initials: H
authors.lastname: Charles
authors.forename: Yvan
authors.initials: Y
authors.lastname: Rahbé
mesh_terms: D000595:Amino Acid Sequence; D001681:Biological Assay; D003001:Cloning, Molecular; D007887:Fabaceae / Q000145:classification / Q000235:genetics*; D014644:Genetic Variation; D007306:Insecticides; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D012639:Seeds / Q000502:physiology*
chemical_list: D007306:Insecticides; D010940:Plant Proteins