title: Novel mode of action of plant defense peptides - hevein-like antimicrobial peptides from wheat inhibit fungal metalloproteases.
abstract: The multilayered plant immune system relies on rapid recognition of pathogen-associated molecular patterns followed by activation of defense-related genes, resulting in the reinforcement of plant cell walls and the production of antimicrobial compounds. To suppress plant defense, fungi secrete effectors, including a recently discovered Zn-metalloproteinase from Fusarium verticillioides, named fungalysin Fv-cmp. This proteinase cleaves class IV chitinases, which are plant defense proteins that bind and degrade chitin of fungal cell walls. In this study, we investigated plant responses to such pathogen invasion, and discovered novel inhibitors of fungalysin. We produced several recombinant hevein-like antimicrobial peptides named wheat antimicrobial peptides (WAMPs) containing different amino acids (Ala, Lys, Glu, and Asn) at the nonconserved position 34. An additional Ser at the site of fungalysin proteolysis makes the peptides resistant to the protease. Moreover, an equal molar concentration of WAMP-1b or WAMP-2 to chitinase was sufficient to block the fungalysin activity, keeping the chitinase intact. Thus, WAMPs represent novel protease inhibitors that are active against fungal metalloproteases. According to in vitro antifungal assays WAMPs directly inhibited hyphal elongation, suggesting that fungalysin plays an important role in fungal development. A novel molecular mechanism of dynamic interplay between host defense molecules and fungal virulence factors is suggested.
authors.affiliation: Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Anna A
authors.initials: AA
authors.lastname: Slavokhotova
authors.forename: Todd A
authors.initials: TA
authors.lastname: Naumann
authors.forename: Neil P J
authors.initials: NP
authors.lastname: Price
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Rogozhin
authors.forename: Yaroslav A
authors.initials: YA
authors.lastname: Andreev
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Vassilevski
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Odintsova
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000935:Antifungal Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D002688:Chitinases / Q000378:metabolism; D005670:Fusarium / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D045726:Metalloproteases / Q000037:antagonists & inhibitors* / Q000235:genetics; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000494:pharmacology*; D059748:Proteolysis; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014908:Triticum / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D037121:Plant Lectins; C045875:hevein; D002688:Chitinases; D045726:Metalloproteases
keywords: Fusarium verticillioides; Triticum kiharae; Zn-metalloproteinase; chitinase; hevein-like antimicrobial peptide