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.

Small molecules below‐ground: the role of specialized metabolites in the rhizosphere

“…() were able to localize more than fifty metabolites in defined Arabidopsis root cell types, with the most predominant classes detected being glucosinolates (GSLs), phenylpropanoids (PPs) and dipeptides (DPs). GSLs and PPs were found to accumulate in the inner cell layer, the cortex, while the downstream products of these two pathways were reported to be secreted to the rhizosphere (Muscolo et al ., ; Halkier and Gershenzon, ; Cesco et al ., ; De Jesus Jatoba et al ., ). Similarly, studies by Sohrabi et al .…”

“…De Jesus Jatoba et al . (), showed that selligueain A, a proanthocyanidin trimer derived from the invasive fern species Pteridium arachnoideum , is found in soil through absorption from dead plant tissues (Figure ). The compound showed phytotoxic activity against Sesamum indicum , largely by inhibiting root and stem growth and affecting chlorophyll content.…”

“…Moussaieff et al (2013) were able to localize more than fifty metabolites in defined Arabidopsis root cell types, with the most predominant classes detected being glucosinolates (GSLs), phenylpropanoids (PPs) and dipeptides (DPs). GSLs and PPs were found to accumulate in the inner cell layer, the cortex, while the downstream products of these two pathways were reported to be secreted to the rhizosphere (Muscolo et al, 2001;Halkier and Gershenzon, 2006;Cesco et al, 2010;De Jesus Jatoba et al, 2016). Similarly, studies by Sohrabi et al (2015Sohrabi et al ( , 2017 indicated that the triterpenoid arabidiol undergoes enzymatic oxidative cleavage in the stele of the Arabidopsis root, but derivatives of the nonvolatile breakdown product, apo-arabidiol, are partly secreted in the rhizosphere.…”

Tree seed rain and seed removal, but not the seed bank, impede forest recovery in bracken (Pteridium aquilinum (L.) Kuhn)‐dominated clearings in the African highlands

“…However, temperate studies have found that bracken fronds and litter impede the incorporation of seeds into the soil (Ghorbani, Le Duc, McAllister, Pakeman, & Marrs, 2006;Pakeman & Hay, 1996). Further, temperate and neotropical studies have found that the soil seed bank in bracken may be negatively affected by predation, allelopathy, or trampling by large mammals (De Jesus Jatoba et al, 2016;Ghorbani et al, 2007). Furthermore, species with longer seed dormancy may possess greater potential to survive bracken interference and can thus dominate the seed bank in bracken (Ssali et al, 2017).…”

Phytotoxic Potential of Benzyl Salicylate and Benzyl Benzoate on Bioindicator and Invasive Species

“…Other authors used pure compounds extracted from different plant species and found their phytotoxic effects on the growth of T. aestivum coleoptiles (Anese, Jatobá, Grisi, Gualtieri, Santos, & Berlinck, 2015;Miranda et al, 2015;Jatobá et al, 2016;Silva et al, 2017). Thus, they confirmed that the initial growth bioassays of T. aestivum coleoptiles are a classic and efficient method to evaluate the phytotoxic activity of compounds belonging to the secondary plant metabolism (Hancock et al, 1964).…”