ARACINs, Brassicaceae-Specific Peptides Exhibiting Antifungal Activities against Necrotrophic Pathogens in Arabidopsis

• Published in: Plant physiology (Bethesda) 2015-03, Vol.167 (3), p.1017-1029
• Main Authors: Neukermans, Jenny, Inzé, Annelies, Mathys, Janick, De Coninck, Barbara, van de Cotte, Brigitte, Cammue, Bruno P.A., Van Breusegem, Frank
• Format: Article
• Language: English
• Subjects: Alternaria - drug effects; Alternaria - growth & development; American culture; Amino Acid Sequence; Antifungal Agents - pharmacology; Antifungals; Antimicrobial Cationic Peptides - pharmacology; Antimicrobials; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - microbiology; Base Sequence; Botrytis - drug effects; Botrytis - growth & development; Brassicaceae - metabolism; Endoplasmic Reticulum - drug effects; Endoplasmic Reticulum - metabolism; Gene Expression Regulation, Plant - drug effects; Genes; Genes, Plant; Infections; Leaves; Organ Specificity - drug effects; Pathogens; Peptides - chemistry; Peptides - genetics; Peptides - pharmacology; Phenotype; Plant cells; Plant Growth Regulators - pharmacology; Plants; Promoter Regions, Genetic - genetics; SIGNALING AND RESPONSE; Species Specificity; Stress, Physiological - drug effects; Subcellular Fractions - drug effects; Subcellular Fractions - metabolism; Transcription, Genetic - drug effects; Transgenic plants
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.114.255505

Plants have developed a variety of mechanisms to cope with abiotic and biotic stresses. In a previous subcellular localization study of hydrogen peroxide-responsive proteins, two peptides with an unknown function (designated ARACIN1 and ARACIN2) have been identified. These peptides are structurally very similar but are transcriptionally differentially regulated during abiotic stresses duringBotrytis cinereainfection or after benzothiadiazole and methyl jasmonate treatments. In Arabidopsis (Arabidopsis thaliana), these paralogous genes are positioned in tandem within a cluster of pathogen defense-related genes. Both ARACINs are small, cationic, and hydrophobic peptides, known characteristics for antimicrobial peptides. Their genes are expressed in peripheral cell layers prone to pathogen entry and are lineage specific to the Brassicaceae family. In vitro bioassays demonstrated that both ARACIN peptides have a direct antifungal effect against the agronomically and economically important necrotrophic fungiB. cinerea, Alternaria brassicicola, Fusarium graminearum,andSclerotinia sclerotiorumand yeast (Saccharomyces cerevisiae). In addition, transgenic Arabidopsis plants that ectopically expressARACIN1are protected better against infections with bothB. cinereaandA. brassicicola.Therefore, we can conclude that both ARACINs act as antimicrobial peptides.