title: Tendril-less regulates tendril formation in pea leaves.
abstract: Tendrils are contact-sensitive, filamentous organs that permit climbing plants to tether to their taller neighbors. Tendrilled legume species are grown as field crops, where the tendrils contribute to the physical support of the crop prior to harvest. The homeotic tendril-less (tl) mutation in garden pea (Pisum sativum), identified almost a century ago, transforms tendrils into leaflets. In this study, we used a systematic marker screen of fast neutron-generated tl deletion mutants to identify Tl as a Class I homeodomain leucine zipper (HDZIP) transcription factor. We confirmed the tendril-less phenotype as loss of function by targeting induced local lesions in genomes (TILLING) in garden pea and by analysis of the tendril-less phenotype of the t mutant in sweet pea (Lathyrus odoratus). The conversion of tendrils into leaflets in both mutants demonstrates that the pea tendril is a modified leaflet, inhibited from completing laminar development by Tl. We provide evidence to show that lamina inhibition requires Unifoliata/LEAFY-mediated Tl expression in organs emerging in the distal region of the leaf primordium. Phylogenetic analyses show that Tl is an unusual Class I HDZIP protein and that tendrils evolved either once or twice in Papilionoid legumes. We suggest that tendrils arose in the Fabeae clade of Papilionoid legumes through acquisition of the Tl gene.
authors.affiliation: Department of Crop Genetics, John Ines Centre, Colney Lane, Norwich NR4 7UH, United Kingdom.
authors.forename: Julie
authors.initials: J
authors.lastname: Hofer
authors.forename: Lynda
authors.initials: L
authors.lastname: Turner
authors.forename: Carol
authors.initials: C
authors.lastname: Moreau
authors.forename: Mike
authors.initials: M
authors.lastname: Ambrose
authors.forename: Peter
authors.initials: P
authors.lastname: Isaac
authors.forename: Susan
authors.initials: S
authors.lastname: Butcher
authors.forename: James
authors.initials: J
authors.lastname: Weller
authors.forename: Adeline
authors.initials: A
authors.lastname: Dupin
authors.forename: Marion
authors.initials: M
authors.lastname: Dalmais
authors.forename: Christine
authors.initials: C
authors.lastname: Le Signor
authors.forename: Abdelhafid
authors.initials: A
authors.lastname: Bendahmane
authors.forename: Noel
authors.initials: N
authors.lastname: Ellis
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D005819:Genetic Markers; D008969:Molecular Sequence Data; D009154:Mutation; D018532:Pisum sativum / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development*; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016415:Sequence Alignment
chemical_list: D005819:Genetic Markers; D010940:Plant Proteins