Transoceanic Dispersal and Subsequent Diversification on Separate Continents Shaped Diversity of the Xanthoparmelia pulla Group (Ascomycota)

In traditional morphology-based concepts many species of lichenized fungi have world-wide distributions. Molecular data have revolutionized the species delimitation in lichens and have demonstrated that we underestimated the diversity of these organisms. The aim of this study is to explore the phylogeography and the evolutionary patterns of the Xanthoparmelia pulla group, a widespread group of one of largest genera of macrolichens. We used a dated phylogeny based on nuITS and nuLSU rDNA sequences and performed an ancestral range reconstruction to understand the processes and explain their current distribution, dating the divergence of the major lineages in the group. An inferred age of radiation of parmelioid lichens and the age of a Parmelia fossil were used as the calibration points for the phylogeny. The results show that many species of the X. pulla group as currently delimited are polyphyletic and five major lineages correlate with their geographical distribution and the biosynthetic pathways of secondary metabolites. South Africa is the area where the X. pulla group radiated during the Miocene times, and currently is the region with the highest genetic, morphological and chemical diversity. From this center of radiation the different lineages migrated by long-distance dispersal to others areas, where secondary radiations developed. The ancestral range reconstruction also detected that a secondary lineage migrated from Australia to South America via long-distance dispersal and subsequent continental radiation

High-Frequency Dynamics of Ocean pH: A Multi-Ecosystem Comparison

The effect of Ocean Acidification (OA) on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO2, reveal sensitivities and responses of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species' natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100. Our data provide a first step toward crystallizing the biophysical link between environmental history of pH exposure and physiological resilience of marine organisms to fluctuations in seawater CO2. Knowledge of this spatial and temporal variation in seawater chemistry allows us to improve the design of OA experiments: we can test organisms with a priori expectations of their tolerance guardrails, based on their natural range of exposure. Such hypothesis-testing will provide a deeper understanding of the effects of OA. Both intuitively simple to understand and powerfully informative, these and similar comparative time series can help guide management efforts to identify areas of marine habitat that can serve as refugia to acidification as well as areas that are particularly vulnerable to future ocean change

Global assessment of genetic variation and phenotypic plasticity in the lichen-forming species Tephromela atra

Understanding how many species exist and the processes by which they form remains a central topic of ecological and evolutionary biology, but represents a special challenge within microbial groups. The lichen-forming fungi represent one of the best examples in which species evolution and diversity create patterns of high phenotypic plasticity coupled with wide geographic distributions. We sampled the lichen-forming species Tephromela atra and related species at a world-wide scale to reconstruct a phylogenetic hypothesis using three nuclear markers. Samples were also studied for morphological and chemical traits to assess how well the phenotypic relationships with species, previously segregated from T. atra, agrees with molecular data. We used a genealogical concordance approach and identified 15 monophyletic clades, which may represent independent lineages. By combining morphological and chemical characters, ecological preferences and geographic origin we distinguish six different species. Although subtle phenotypical traits are frequently used for describing previously cryptic species in fungi, the continuum of variability found in morphology and chemical patterns in T. atra prevents the description of new taxa with characteristic traits. We observed that phenotypic characters arise in parallel at local or regional scale but are not correlated with genetic isolation. Therefore, they are insufficient for characterizing species with broad geographic ranges within T. atra

Phytochemical study and antioxidant, antimicrobial and anticancer activities of Melanelia subaurifera and Melanelia fuliginosa lichens

The aim of this study was to investigate antioxidant, antimicrobial and anticancerous activity of Melanelia subaurifera and Melanelia fuliginosa. The phytochemical analysis was determined by HPLC–UV method. Antioxidant activity was evaluated by DPPH and reducing power assay while antimicrobial activity was determined by minimal inhibitory concentration. The cytotoxic activity was tested using MTT method. The method for quantification of 2′-O-methyl anziaic acid and lecanoric acid in these lichens using RF-HPLC was also developed and validated. The depsides (lecanoric acid, gyrophoric acid, atranorin, anziaic acid and 2′-O-methyl anziaic acid), and dibenzofurane (usnic acid) were identified in these lichens. The antioxidant activity (IC(50)) of lichens extracts ranged from 121.52 to 424.51 μg/ml. 2′-O-Methyl anziaic acid showed the highest antimicrobial activity with MIC ranging from 0.0625 to 1 mg/ml. M. subaurifera extract showed the highest cytotoxic activity against the tested cell lines (IC(50) = 9.88 to 31.64 μg/ml)