New Taxa of Streptophyte Algae (Streptophyta) from Terrestrial Habitats Revealed Using an Integrative Approach

Abstract

Two new genera (Streptosarcina and Streptofilum) and three new species (Streptosarcina arenaria, S. costaricana and Streptofilum capillatum) of streptophyte algae were detected in cultures isolated from terrestrial habitats of Europe and Central America and described using an integrative approach. Additionally, a strain isolated from soil in North America was identified as Hormidiella parvula and proposed as an epitype of this species. The molecular phylogeny based on 18S rRNA and rbcL genes, secondary structure of ITS-2, as well as the morphology of vegetative and reproductive stages, cell ultrastructure, ecology and distribution of the investigated strains were assessed. The new genus Streptosarcina forms a sister lineage to the genus Hormidiella (Klebsormidiophyceae). Streptosarcina is characterized by packet-like (sarcinoid) and filamentous thalli with true branching and a cell organization typical for Klebsormidiophyceae. Streptofilum forms a separate lineage within Streptophyta. This genus represents an easily disintegrating filamentous alga which exhibits a cell coverage of unique structure: layers of submicroscopic scales of piliform shape covering the plasmalemma and exfoliate inside the mucilage envelope surrounding cells. The implications of the discovery of the new taxa for understanding evolutionary tendencies in the Streptophyta, a group of great evolutionary interest, are discussed.

Light and Dehydration but Not Temperature Drive Photosynthetic Adaptations of Basal Streptophytes (Hormidiella, Streptosarcina and Streptofilum) Living in Terrestrial Habitats

“…Although, the position of Mesostigmatophyceae and Chlorokybophyceae within Streptophyta has recently been debated [5, 6], members of the Klebsormidiophyceae are considered as a basal lineage of Streptophyta [6], whilst the Zygnematophyceae are currently believed to be the sister group of land plants [7, 8]. In the present study, three members of basal terrestrial streptophytes, including the newly described genera Streptosarcina Mikhailyuk et Lukešová (sister lineage to Hormidiella Iyengar et Kanthamma) and Streptofilum Mikhailyuk et Lukešová (separate lineage inside Streptophyta), as well as a new epitype strain of Hormidiella parvula Iyengar et Kanthamma [9] were investigated.…”

“…In this study, we aimed to understand the photosynthetic adaptations employed by basal streptophytes to successfully colonise terrestrial habitats. We have taken advantage of newly described genera and species of basal streptophytes [9], which should broaden our understanding of the physiological behaviour of ancestral streptophytes. We have emphasised species photosynthetic traits, light acclimation abilities and protective mechanisms (against PAR and UVR).…”

Biodiversity of Algae and Cyanobacteria in Biological Soil Crusts Collected Along a Climatic Gradient in Chile Using an Integrative Approach

“…Nucleotide sequences of small subunit (SSU) rRNA gene together with ITS-1-5.8S-ITS-2 region of Chlorophyta and Streptophyta were amplified using a set of Taq PCR Mastermix Kit (Qiagen, Hilden, Germany), a complex of EAF3, ITS055R [ 42 , 43 ] and algal-specific primers G500 F and G800R [ 30 ]. The PCR was conducted according to Mikhailyuk et al [ 44 ]. The PCR products were cleaned with the SureClean Plus purification kit (Bioline, Luckenwalde, Germany) according to the manufacturer’s instructions.…”

Dictyosphaerium‐like morphotype in terrestrial algae: what is Xerochlorella (Trebouxiophyceae, Chlorophyta)?1

“…PCR reactions were made in a thermocycler T gradient Thermoblock (Biometra, Analytik Jena, Germany) under conditions described in a previous paper (Mikhailyuk et al. ). PCR products were cleaned using a Qiagen PCR purification kit (Qiagen GmbH) according to the manufacturer's instructions.…”