title: The alteration of plant morphology by small peptides released from the proteolytic processing of the bacterial peptide TENGU.
abstract: Phytoplasmas are insect-borne plant pathogenic bacteria that alter host morphology. TENGU, a small peptide of 38 residues, is a virulence factor secreted by phytoplasmas that induces dwarfism and witches' broom in the host plant. In this study, we demonstrate that plants process TENGU in order to generate small functional peptides. First, virus vector-mediated transient expression demonstrated that the amino-terminal 11 amino acids of TENGU are capable of causing symptom development in Nicotiana benthamiana plants. The deletion of the 11th residue significantly diminished the symptom-inducing activity of TENGU, suggesting that these 11 amino acids constitute a functional domain. Second, we found that TENGU undergoes proteolytic processing in vitro, generating peptides of 19 and 21 residues including the functional domain. Third, we observed similar processing of TENGU in planta, and an alanine substitution mutant of TENGU, for which processing was compromised, showed reduced symptom induction activity. All TENGU homologs from several phytoplasma strains possessed similar symptom induction activity and went through processing, which suggests that the processing of TENGU might be related to its function.
authors.affiliation: Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Sugawara
authors.forename: Youhei
authors.initials: Y
authors.lastname: Honma
authors.forename: Ken
authors.initials: K
authors.lastname: Komatsu
authors.forename: Misako
authors.initials: M
authors.lastname: Himeno
authors.forename: Kenro
authors.initials: K
authors.lastname: Oshima
authors.forename: Shigetou
authors.initials: S
authors.lastname: Namba
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000378:metabolism; D010802:Phylogeny; D045582:Phytoplasma / Q000378:metabolism / Q000472:pathogenicity*; D010935:Plant Diseases / Q000382:microbiology; D010936:Plant Extracts / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012336:RNA, Ribosomal, 16S; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000378:metabolism / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010446:Peptide Fragments; D010936:Plant Extracts; D012336:RNA, Ribosomal, 16S; D011994:Recombinant Proteins; D037521:Virulence Factors