Characterization of ciliate diversity in bromeliad tank waters from the Brazilian Atlantic Forest

Abstract

Bromeliads are a diverse group of plants that includes many species whose individuals are capable of retaining water, forming habitats called phytotelmata. These habitats harbor a diversity of organisms including prokaryotes, unicellular eukaryotes, metazoans, and fungi. Among single-celled eukaryotic organisms, ciliates are generally the most abundant. In the present study, we used Illumina DNA sequencing to survey the eukaryotic communities, especially ciliates, inhabiting the tanks of the bromeliads Aechmea gamosepala and Vriesea platynema in the Atlantic Forest of southern Brazil. Filtered sequences were clustered into distinct OTUs using a 99% identity threshold, and then assigned to phylum and genus using a BLAST-based approach (implemented in QIIME) and the SILVA reference database. Both bromeliad species harbored very diverse eukaryotic communities, with Arthropoda and Ciliophora showing the highest abundance (as estimated by the number of sequence reads). The ciliate genus Tetrahymena was the most abundant among single-celled organisms, followed by apicomplexan gregarines and the ciliate genus Glaucoma. Another interesting finding was the presence and high abundance of Trypanosoma in these bromeliad tanks, demonstrating their occurrence in this type of environment. The results presented here demonstrate a hidden diversity of eukaryotes in bromeliad tank waters, opening up new avenues for their in-depth characterization.

Seasonal Physiological Parameters and Phytotelmata Bacterial Diversity of Two Bromeliad Species (Aechmea gamosepala and Vriesea platynema) from the Atlantic Forest of Southern Brazil

“…There are few studies on the prokaryotic and eukaryotic communities from phytotelmata of Southern Brazilian bromeliads [18,24,82]. Our survey presents the description of bacterial communities from bromeliad phytotelmata using DNA metabarcoding, the seasonal physiological changes of the host plants and some of their possible interactions in the Atlantic Forest in southern Brazil.…”

“…Total DNA was extracted from 250-µL phytotelmata water and debris samples using the DNeasy Blood & Tissue kit (Qiagen, Valencia, CA, USA), as described by Simão et al [18]. Partial 16S rRNA gene sequences were amplified using universal primers 515F and 806R [41], with the addition of a barcode sequence and the required Illumina sequencing adapters [42].…”

“…All sampled individuals were epiphytic, placed under shade conditions below a dense canopy, and distributed along a steep forest trail spanning ca. 450 m from sampling point 1 to point 5 (see Figure 1 in [18]). Sampling was carried out in 2010, with one sampling campaign being performed per season.…”

“…We assessed the total water volume present in the tanks including debris of each target bromeliad. About 2 mL of water and debris were collected using a Pasteur pipette and were mixed with 2 mL of Tris-EDTA SDS (TES) lysis buffer (see [18]). After collection, samples were stored at −20 • C for DNA extraction and microbial DNA metabarcoding analyses.…”

“…This strategy was supported by the plant physiological data for both species (see Results), since the only parameter that differed significantly among individuals of the same species sampled on the same day was sugar level between Diversity 2019, 11, 111 5 of 20 points 1 and 5. The same DNA extracts used here were employed in a separate study focusing on the eukaryotic microbial community [18].…”