title: Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil.
abstract: The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant's dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of allelopathy in the dominance processes of this plant in the areas where it occurs.
authors.affiliation: Laboratory of Plant Phytochemical and Reproductive Ecophysiology Studies, Department of Botany, Universidade Federal de São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: de Jesus Jatoba
authors.affiliation: Cádiz Allelopathy Group (GAC), Organic Chemistry Department, Facultad de Ciencias, Universidad de Cádiz (UCA), Puerto Real, Cádiz, Spain.
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Varela
authors.affiliation: Cádiz Allelopathy Group (GAC), Organic Chemistry Department, Facultad de Ciencias, Universidad de Cádiz (UCA), Puerto Real, Cádiz, Spain.
authors.forename: José Maria Gonzalez
authors.initials: JM
authors.lastname: Molinillo
authors.affiliation: Laboratory of Micromolecular Biochemistry of Microorganisms (LaBioMMi), Chemistry Department, Universidade Federal de São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
authors.forename: Zia
authors.initials: Z
authors.lastname: Ud Din
authors.affiliation: Laboratory of Plant Phytochemical and Reproductive Ecophysiology Studies, Department of Botany, Universidade Federal de São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
authors.forename: Sonia Cristina
authors.initials: SC
authors.lastname: Juliano Gualtieri
authors.affiliation: Laboratory of Micromolecular Biochemistry of Microorganisms (LaBioMMi), Chemistry Department, Universidade Federal de São Carlos (UFSCar), São Carlos, São Paulo, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Rodrigues-Filho
authors.affiliation: Cádiz Allelopathy Group (GAC), Organic Chemistry Department, Facultad de Ciencias, Universidad de Cádiz (UCA), Puerto Real, Cádiz, Spain.
authors.forename: Francisco Antonio
authors.initials: FA
authors.lastname: Macías
mesh_terms: D064089:Allelopathy; D000898:Antibiosis; D001938:Brazil; D015394:Molecular Structure; D064209:Phytochemicals / Q000737:chemistry / Q000633:toxicity; D010936:Plant Extracts / Q000737:chemistry / Q000633:toxicity; D018517:Plant Roots / Q000737:chemistry / Q000166:cytology / Q000254:growth & development; D044945:Proanthocyanidins; D032498:Pteridium / Q000737:chemistry* / Q000502:physiology*; D031685:Sesamum / Q000254:growth & development; D012987:Soil / Q000737:chemistry; D014908:Triticum / Q000502:physiology
chemical_list: D064209:Phytochemicals; D010936:Plant Extracts; D044945:Proanthocyanidins; D012987:Soil; C013221:proanthocyanidin