Lichen Pseudevernia Furfuracea Research Articles

Optimizing Moss and Lichen Transplants as Biomonitors of Airborne Anthropogenic Microfibers.

Anthropogenic microfibers (mfs) are synthetic particles composed of cellulose (cotton, rayon, acetate, etc.) or petrochemical-based polymers (i.e., microplastics-MPs) that are less than 5 mm in length. The accumulation of mfs, including MPs, in the moss Hypnum cupressiforme and the lichen Pseudevernia furfuracea was compared in a transplant experiment lasting 6 weeks. We also tested the effects of the bag used for transplants on the accumulation of mfs. Anthropogenic particles trapped by both biomonitors were mostly filamentous (99% mfs), and their number was overall higher in the moss (mean ± s.d. 102 ± 24) than in the lichen (mean ± s.d. 87 ± 17), at parity of sample weight. On average, mfs found in lichen were significantly longer than those found in moss bags, suggesting that lichens are less efficient at retaining smaller mfs. Exposure without the net yielded a higher mfs number accumulation in both species, indicating that "naked" transplants provide greater sensitivity. The calculation of daily fluxes evidenced a loss of mfs in the lichen, suggesting the presence of more stable bonds between moss and mfs. Raman microspectroscopy carried out on about 100 debris confirms the anthropogenic nature of mfs, of which 20% were MPs. Overall results indicate that moss is preferable to lichen in the biomonitoring of airborne mfs especially when exposed naked.

Agricultural drift depositional simulation of a copper-based fungicide and its effects on non-target terrestrial and freshwater compartments.

Our research investigated the potential impacts of the fungicide Bordeaux mixture drift processes on off-target species representing terrestrial vegetation and fluvial-lacustrine zooplankton. The simulation of drift events was carried out by a predictive scaling analysis of the quantities potentially exported to a predetermined area adjacent to an agricultural field. The theoretical rate of deposition on a terrestrial species, the lichen Pseudevernia furfuracea, was calculated following high (4 kg ha-1) and low (2 kg ha-1) rate treatments using anti-drift nozzles and non-anti-drift nozzles. The experimental set up consisted in 40 boxes holding lichen thalli, all stored in a climatic chamber for 40 days. Spraying of the fungicide was alternated with rainfall simulations to reproduce scenarios related to agricultural practices. Following a single simulation, anti-drift nozzles resulted in a higher overall load deposited per unit of lichen surface area compared to non-anti-drift nozzles, although both loads significantly differed from controls. However, only anti-drift nozzles, associated with the high rate, caused a remarkable impairment of several ecophysiological parameters, differing (p < 0.05) from controls. Rainfalls promoted activation of lichen metabolism, mitigating the cell damage, but exported only 2.5% of the copper deposited on the thalli surfaces. Nevertheless, the exposure of Daphnia magna neonates to leachates showed significant outcomes for the two rates. After only 24 h, leachates resulting from the high application rate led to widespread mortality, which appeared to be extremely relevant after 48 h, whereas the lower rate induced much lower toxicity for both exposure times.

The Role of Gamma-Amino Butyric Acid in Short-Term High Temperature Acclimation in Lichen Pseudevernia furfuracea

Objective: Global warming causes many different stresses for plants. High-temperature stress is one of the important problems caused by global warming. Plants develop various tolerance mechanisms to protect themselves against these stresses. γ-Aminobutyric acid (GABA) metabolism has a critical role in various biological processes in plants. GABA plays a critical role in the acclimation to different stress conditions in plants. Lichens can grow in environments exposed to severe abiotic stresses such as drought and extreme heat. The major aim of this study was to identify whether GABA accumulation could improve short-term, high-temperature tolerance in lichen Pseudevernia furfuracea. Materials and Methods: For this aim, P. furfuracea samples were kept in petri dishes in an incubator at 45 ± 2°C for 24 and 48 h. We analyzed the chlorophyll a/b ratio, GABA content, glutamate decarboxylase (GAD) and glutamate dehydrogenase (GDH) activities, which are important enzymes involved in the GABA shunt, and also peroxidase (POD) and catalase (CAT) activities of the antioxidant metabolism. Results: Our study indicated that the chlorophyll a/b ratio was not changed significantly under 45°C within 48 h. POD and CAT activities were significantly decreased in lichen thalli under 45°C, however; GABA accumulation was approximately enhanced by 1.5-fold depending on the time exposure. GAD and GDH activities were significantly increased under high temperature conditions. Conclusions: The acclimilation of P. furfuracea to high temperatures may be related to the increase in GAD and GDH activities. Our findings provided evidence that the GABA shunt could help lichen P. furfuracea to acclimate to high temperatures.

Lichen biomonitoring of airborne trace elements in the industrial-urbanized area of eastern algiers (Algeria)

This study established a comprehensive picture of airborne metal pollution in the industrial urbanized area of the East of Algiers (Algeria). Thalli of the epiphytic lichen Pseudevernia furfuracea were transplanted from a remote unpolluted forest (Theniet El-Had) to eighteen biomonitoring sites in the Rouiba−Reghaia region exhibiting contrasting anthropogenic activities, including the wooded Reghaia Nature Reserve. Thirty-three metals and rare earths, and Br in lichen thalli were determined after 3 months exposure by X-ray fluorescence and instrumental neutron activation analysis. All biomonitored element concentrations exhibited dramatic increases compared to the control region, and calculation of contamination factor index unveiled that Sb, Pb, Ti, V, Ce, La, Ga, Cr, Cs, Cu, and Cd had the highest contamination levels in almost all the study sites. The degree of ambient pollution was assessed using enrichment factor, pollution load index, cluster analysis, and principal components analysis. A multiple correspondence analysis showed Pb, Sb, and Ga to be highly enriched with heavy contamination in all study sites, even in the Reghaia Nature Reserve.

Simulation of Drift Depositional Rate of the Fungicide Fosetyl and Its Effects on Non-vascular Plants: Study Case of the Epiphytic Lichen Pseudevernia furfuracea

The epiphytic lichen Pseudevernia furfuracea was exposed to a simulation of drift deposition rate of the fungicide Fosetyl-Al in an indoor controlled environment by testing two exposure factors: pesticide concentrations (based on the application rates of 4kgha-1 and 1.6kgha-1) and drop sizes (anti-drift nozzle: 386-484μm; non-anti-drift nozzle: 159-231μm) for a total of four treatments. Drift for higher application rate was simulated once and that for the lower one twice to reproduce agricultural practices. Following fungicide spraying, we measured the concentration of Fosetyl and phosphonic acid in lichen thalli, and the response of ecophysiological status parameters. No trace of Fosetyl was quantifiable 4days after each treatment, being detected only phosphonic acid whose concentrations stayed substantially unchanged for the whole duration of the experiment (40days) and resulting affected by application rate and not by drop size. Both pesticide concentrations caused a remarkable harmful effect that, however, was statistically significant vs control group only starting from the 20th day of stay in the climatic chamber. The drift associated with the higher rate resulted, on average, to be 83% more effective, with the most affected parameters being membrane integrity, lipid peroxidation and photosynthetic pigments. Because the selected lower rate can be considered a quite low value when compared with the rank of used rates for crop protection, the Fosetyl-Al formulate is classifiable as hazardous for its effect on non-target organisms.

Evaluation of the Ecotoxicity of New Polyurethane Composites on Target Organisms for Aquatic and Atmospheric Environments.

The present study investigated if new biocomposite materials, polyurethanes (PURs) added with functionalized cellulose fibers, produce potential toxic effects on two target organisms currently used in biomonitoring the quality of two different environmental compartments. Natural fibers were extracted from the species Spartium junceum L., a shrub commonly found in the southern region of the Mediterranean having a high cellulose content. All PURs produced were characterized by Fourier-transform infrared spectroscopy, and their structure was analyzed by scanning electron microscopy. We measured the effects of exposure to aromatic and aliphatic PUR composites (containing or not cellulose fibers) on the aquatic model organism Daphnia magna Straus, a freshwater crustacean (Cladocera), and a biomonitor of air quality, the fruticose epiphytic lichen Pseudevernia furfuracea (L.) Zopf. Leachates from aliphatic PUR composite not containing cellulose are more toxic to D. magna than all others, showing a slight acute toxicity in the case of the shortest exposure (24 h) and a moderate acute toxicity in the longer one (48 h). This effect is most likely due to the presence of free organic ammines and amides, which, in their turn, are immobilized in composites containing cellulosic fibers because of the considerable amount of chemical functional groups. Regarding lichens, both types of aliphatic PURs resulted in a toxic effect. Formulate not added with cellulose strongly promoted fungal peroxidation, whereas that which was functionalized affected the pigment concentration of the algal partner. Our results suggest that the use of cellulose in PUR production, in general, can limit the ecotoxicological effects on both test organisms and reduce the potential environmental impact due to this type of polymer. Environ Toxicol Chem 2023;42:421-436. © 2022 SETAC.

Detection of air quality improvement within a suburban district (southern Italy) by means of lichen biomonitoring

The present work compared both the bioaccumulation of trace elements and the values of ecophysiological parameters measured in thalli of the lichen Pseudevernia furfuracea (L.) Zopf in two monitoring campaigns performed before and after improvement measures put in place by a 15 MW biomass power plant (BPP): the activation of a concentrated solar thermodynamic plant and the increasing percentage of exhausted olive pomace used as fuel. The cases of no enrichment and moderate enrichment change from 49 and 17% in 2013 to 68 and 4.2% in 2019, respectively. Several metals in 2019, show a Delta (difference between exposed and not exposed lichen thalli concentration) that is significantly lower than in 2013. The spatial pattern of contamination is comparable between the two years. However, the BPP affects the spatial variation of Ti, Al, V and Co in both 2019 and 2013, but only in the latter year also that of Cu, Cr and As which, in some monitoring sites, developed extremely high levels of enrichment. Traffic, whose rate increased over time, constantly influences the bioaccumulation of Cu, Sb and Mo. In 2019, the lichen oxidative stress is significantly reduced as well as the number of correlations between malondialdehyde levels and those of trace elements. Pigment values never differ (p > 0.05) from pre-exposure levels. Our results suggest that the development of hybrid plants, as well as a better fuel selection can reduce the environmental impact due to the combustion of biomass contributing to make this type of energy source more sustainable.

(S)-5-Methylmellein Isolated from an Endogenous Lichen Fungus Rosellinia corticium as a Potent Inhibitor of Human Monoamine Oxidase A

In this study, the inhibitory activities against human monoamine oxidases (hMAOs) were evaluated using a library of 195 endogenous lichen fungi from Ukraine. Among them, the extract ELF68 of the endogenous fungus Rosellinia corticium from the lichen Pseudevernia furfuracea (L.) Zopf. exhibited the strongest inhibitory activity against hMAO-A. Using the activity-guided method, (S)-5-methylmellein (5MM) was isolated from the extract and had an IC50 value of 5.31 µM for hMAO-A with a lower potency for hMAO-B (IC50 = 9.15 µM). Compound 5MM also moderately inhibited acetylcholinesterase (IC50 = 27.07 µM) but very weakly inhibited butyrylcholinesterase and β-secretase. Compound 5MM had a Ki value of 2.45 μM and was a reversible competitive inhibitor of hMAO-A. A molecular docking study predicted that (S)-5MM showed higher binding affinity for hMAO-A (−6.8 kcal/mol) than hMAO-B (−6.4 kcal/mol). Its isomer, (R)-5MM, exhibited lower binding affinities for hMAO-A (−6.6 kcal/mol) and hMAO-B (−5.2 kcal/mol), compared to (S)-5MM. The S-form interacted with hMAO-A through hydrogen bonding with the Phe208 residue (distance: 1.972 Å), while the R-form interacted with the Asn181 residue (2.375 Å). The results of an in silico pharmacokinetic analysis indicated that 5MM did not violate Lipinski’s five rules and showed high gastrointestinal absorption and blood–brain barrier permeability. These results suggest that 5MM can be considered a candidate in the treatment of neuropsychiatric disorders, such as depression and cardiovascular disease.

Pro-Apoptotic Potential of Pseudevernia furfuracea (L.) Zopf Extract and Isolated Physodic Acid in Acute Lymphoblastic Leukemia Model In Vitro.

Acute lymphoblastic leukemia (ALL) is the most frequently diagnosed type of leukemia among children. Although chemotherapy is a common treatment for cancer, it has a wide range of serious side effects, including myelo- and immunosuppression, hepatotoxicity and neurotoxicity. Combination therapies using natural substances are widely recommended to attenuate the adverse effects of chemotherapy. The aim of the present study was to investigate the anti-leukemic potential of extract from the lichen Pseudevernia furfuracea (L.) Zopf (PSE) and isolated physodic acid (Phy) in an in vitro ALL model. A screening assay, flow cytometry and Western blotting were used to analyze apoptosis occurrence, oxidative stress, DNA damage and stress/survival/apoptotic pathway modulation induced by the tested substances in Jurkat cells. We demonstrate for the first time that PSE and Phy treatment-induced intrinsic caspase-dependent cell death was associated with increased oxidative stress, DNA damage and cell cycle arrest with the activation of cell cycle checkpoint proteins p53, p21 and p27 and stress/survival kinases p38 MAPK, JNK and PI3K/Akt. Moreover, using peripheral T lymphocytes, we confirmed that PSE and Phy treatment caused minimal cytotoxicity in normal cells, and therefore, these naturally occurring lichen secondary metabolites could be promising substances for ALL therapy.

Depside and Depsidone Synthesis in Lichenized Fungi Comes into Focus through a Genome-Wide Comparison of the Olivetoric Acid and Physodic Acid Chemotypes of Pseudevernia furfuracea.

Primary biosynthetic enzymes involved in the synthesis of lichen polyphenolic compounds depsides and depsidones are non-reducing polyketide synthases (NR-PKSs), and cytochrome P450s. However, for most depsides and depsidones the corresponding PKSs are unknown. Additionally, in non-lichenized fungi specific fatty acid synthases (FASs) provide starters to the PKSs. Yet, the presence of such FASs in lichenized fungi remains to be investigated. Here we implement comparative genomics and metatranscriptomics to identify the most likely PKS and FASs for olivetoric acid and physodic acid biosynthesis, the primary depside and depsidone defining the two chemotypes of the lichen Pseudevernia furfuracea. We propose that the gene cluster PF33-1_006185, found in both chemotypes, is the most likely candidate for the olivetoric acid and physodic acid biosynthesis. This is the first study to identify the gene cluster and the FAS likely responsible for olivetoric acid and physodic acid biosynthesis in a lichenized fungus. Our findings suggest that gene regulation and other epigenetic factors determine whether the mycobiont produces the depside or the depsidone, providing the first direct indication that chemotype diversity in lichens can arise through regulatory and not only through genetic diversity. Combining these results and existing literature, we propose a detailed scheme for depside/depsidone synthesis.

Identification of a lichen depside polyketide synthase gene by heterologous expression in Saccharomyces cerevisiae

Lichen-forming fungi produce a variety of secondary metabolites including bioactive polyketides. Advances in DNA and RNA sequencing have led to a growing database of new lichen gene clusters encoding polyketide synthases (PKS) and associated ancillary activities. Definitive assignment of a PKS gene to a metabolic product has been challenging in the lichen field due to a lack of established gene knockout or heterologous gene expression systems. Here, we report the reconstitution of a non-reducing PKS gene from the lichen Pseudevernia furfuracea and successful heterologous expression of the synthetic lichen PKS gene in engineered Saccharomyces cerevisiae. We show that P. furfuracea PFUR17_02294 produces lecanoric acid, the depside dimer of orsellinic acid, at 360 mg/L in small-scale yeast cultures. Our results unequivocally identify PFUR17_02294 as a lecanoric acid synthase and establish that a single lichen PKS synthesizes two phenolic rings and joins them by an ester linkage to form the depside product.

Морфологическая пластичность и структура популяции лишайника Pseudevernia furfuracea (L.) Zopf в изменяющихся условиях среды

Морфологическая пластичность и структура популяции лишайника Pseudevernia furfuracea (L.) Zopf в изменяющихся условиях среды

Element accumulation performance of living and dead lichens in a large-scale transplant application

In bioaccumulation studies, sample devitalization through acid washing or oven drying is commonly applied to enhance the element accumulation efficiency of moss sample. Such aspect, however, has never been considered in biomonitoring surveys using lichens. In this study, the trace element accumulation performance of living (L) and dead (D) samples of the lichen Pseudevernia furfuracea was compared by a side-by-side transplanting at 40 sites in a large, mixed land use area of NE Italy for 8 weeks. Devitalization was achieved without any physico-chemical treatments, by storing lichen samples in a dark cool room for 18 months. Health status of lichens was assessed before and after the sample exposure by chlorophyll fluorescence emission. Although elemental analysis of the two exposed sample sets revealed a similar trace element pollution scenario, the content of 13 out of the 24 selected elements was higher in D samples. By expressing results as exposed-to-unexposed (EU) ratio, D samples show a higher bioaccumulation signal in 80% of transplant sites for Al, Ca, Fe, Hg, Pb and Ti. Overall, the health status of lichen samples might lead to interpretational discrepancies when EU ratio is classified according to the recently proposed bioaccumulation scale.

Biosorption study for removal of methylene blue dye from aqueous solution using a novel activated carbon obtained from nonliving lichen (Pseudevernia furfuracea (L.) Zopf.)

To the best of our knowledge, there is no study on the utilization of lichens in the production of activated carbon while lichens are natural, renewable and cheap sources. In this study, a novel activated carbon (ACLPF) from non-living lichen Pseudevernia furfuracea (L.) Zopf. (LPF) was produced, and physicochemical and morphological characterization of the ACLPF were examined with the help of Brauner-Emmett-Teller surface area (BET), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) techniques. The obtained ACLPF had a high surface area (851.24 m2g−1) and a large pore volume (0.225 cm3g−1) with micropore size distribution (1.06 nm). To investigate the usability of the ACLPF in wastewater treatment, batch mode biosorption experiments were carried out, and the effect of various parameters on methylene blue (MB) dye removal from aqueous solution were studied. The experimental data were fitted with 4 different kinetic models (pseudo first-order (PFO), pseudo second-order (PSO), Elovich model (EM) and intra-particle diffusion (IDM)) and 3 different isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich (D-R)). It was found that the maximum biosorption capacity and the removal efficiency (%) were as 243.9024 mgg−1 and 91.38%, respectively. The biosorption of MB onto the ACLPF was chemical biosorption due to the activation energy (Ea) to be 42.63 kJmol−1, and the process was endothermic (ΔH0=61.4163 kJmol−1), feasible and spontaneous (ΔG0= -7.0278 kJmol−1 at 318 K and ΔS0 =0.1707 kJmol−1K−1) thermodynamically.The novelty of this study is that besides obtained and characterized the activated carbon (ACLPF) from the non-living LPF at the first time, the discussions on the biosorption capability of the ACLPF for the removal of MB dye from aqueous media are included in this paper.

Removal of methylene blue dye from aqueous solution by nonliving lichen (Pseudevernia furfuracea (L.) Zopf.), as a novel biosorbent

The use of lichens is insufficient in industry. To the best of our knowledge, there is no study on the use of lichens in the removal of dyes from aqueous media. The aim of this study is to draw attention to the biosorption capabilities of lichens which are natural, renewable and inexpensive sources, and to investigate the usability of nonliving lichen Pseudevernia furfuracea (L.) Zopf. (LPF) in methylene blue (MB) dye removal from aqueous solution. With the green chemistry approach, no chemical treatment was applied to the LPF and it was used as a natural biosorbent for the biosorption. The LPF samples were prepared and characterized and performed batch mode biosorption experiments studying the effect of various parameters on MB biosorption. The experimental data were fitted with four different kinetic models (pseudo-first order, pseudo-second order, Elovich model and intra-particle diffusion) which were evaluated for their validity. Identification of the biosorption mechanism of MB onto the LPF was performed by isotherm studies via three isotherm models [Langmuir, Freundlich and Dubinin–Radushkevich (D–R)], and the parameters of each model were determined. It was concluded that the biosorption rate and yield were high, the type of biosorption of MB onto the LPF was defined as chemical biosorption, and the surface of the LPF was decided energetically heterogeneous. The results indicate that the LPF biomass can be attractive options for MB dye removal from aqueous media.

Implication of vitality, seasonality and specific leaf area on PAH uptake in moss and lichen transplanted in bags

• Vitality, season and SLA effects on PAH uptake were tested in moss and lichen bags. • The highest uptake occurred in winter with 4-rings PAHs dominating in both species. • F v /F m showed that both species were in cryptobiosis during exposure. • The higher the SLA (moss), the lower the PAH uptake. • Lichen performed better than moss being able to entrap PAHs in the body of thallus. In this work the moss Hypnum cupressiforme and the lichen Pseudevernia furfuracea were exposed in bags for six weeks alive and oven-devitalized during summer and winter; the content of 24 PAHs was quantified to evaluate the effect of vitality, seasonality and specific leaf area (SLA) on PAH uptake and profiling. Vitality was followed throughout the exposure by measuring PSII maximal photochemical efficiency (F v /F m ). In summer, a limited PAH signal was detected, with no significant increase, or even loss, of these compounds. During winter, a significant increase of PAHs was measured in both biomonitors, especially in those devitalized, with a lower baseline PAH content compared to alive material. This result suggests that PAH uptake mostly relies on passive mechanisms. Accordingly, F v /F m demonstrated that moss and lichen exposed alive spent most of the exposure time in cryptobiosis. In both biomonitors 4-rings PAHs prevailed, followed by 2-3-rings in lichen and 5-6-rings in moss. Lichen performed better than moss, due to the ability to entrap PAHs in the body of thalli, preserving these compounds during the exposure. A formula was developed to express the accumulated PAHs in terms of flux, that resulted higher in lichen than in moss. Oven devitalized lichen exposed in winter provided the highest uptake, indicating that morphology, SLA and seasonality represent key parameters in PAH biomonitoring.

Insights into physiological responses of mosses Physcomitrella patens and Pohlia drummondii to lichen secondary metabolites.

It is widely accepted that allelopathy among mosses and lichens do exist due to its similar ecological needs, though it is rarely documented. With an aim to test whether there is an effect of allelochemicals to mosses, we grow axenically two moss species (namely Physcomitrella patens and Pohlia drummondii) in controlled conditions and use them to test the effect of lichen Pseudevernia furfuracea acetone extracts containing active compounds: atranorin, chloratranorin, and physodic acid. The photosynthesis value and the biochemical parameters were measured to detect changes in moss organisms upon application of different concentration of lichen extract. The results obtained clearly showed that both moss species reacted to allelochemicals applied in test but to different extent. This suggests that tested moss species have various patterns on reaction to allelochemicals, and that the process of allelopathy is rather a recently coevolving one, than pre-defined. The lichen secondary metabolites are allelochemicals effective also to moss species that are not selected lichen cohabitants.

Beyond ozone-tolerance: Effects of ozone fumigation on trace element and PAH enriched thalli of the lichen biomonitor Pseudevernia furfuracea

In this study, the effects of ozone (O3) on the physiology of the lichen Pseudevernia furfuracea var. furfuracea previously subjected to field stressing conditions were assessed. Samples collected in a pristine site were exposed for 6 weeks at 3 sites characterized by different pollution, e.g. elemental and PAH depositions (site RU, close to wood-burning house chimneys; site UI, close to cast-ironworks; site CK, in a semi-natural context). Afterwards, samples were transferred to controlled fumigation chambers, where they were either O3-treated for 2 weeks (250 ppb O3 for 5 h day−1, O3+ samples) or not (0 ppb O3, O3− samples). Three physiological markers (Fv/Fm, maximum quantum yield of primary photochemistry; MDA, malondialdehyde content; potassium leakage) as well as elemental and PAH concentrations were measured in matched sets of sample replicates at each experimental step. Data were explored by multivariate techniques and the effects of field exposure and fumigation were tested by generalized linear models (GLM). Detrimental effects on MDA and Fv/Fm were observed limited to samples exposed in RU and UI sites. Physiological parameters in O3-treated samples showed heterogeneous variation patterns with respect to field-exposed ones. A recovery of Fv/Fm was observed in RU- and UI-exposed samples, whereas a significant increase of MDA was highlighted limited to CK O3+ and CK O3− samples, possibly related to a “chamber effect”. Overall, the impairment caused by ozonation was limited, proving the strong O3-tolerance of our test species. Interestingly, the content of the most abundant 4-ring PAHs in RU O3+ samples, which underwent the highest field enrichment of PAHs, was significantly lower than that of matched RU O3− samples. This suggested a possible role of ozone in degrading PAHs at thallus level, with interesting interpretative repercussions in the context of transplant-based surveys aimed at evaluating PAH depositions when O3 ground levels are high.

Evaluation of glyphosate drift and anthropogenic atmospheric trace elements contamination by means of lichen transplants in a southern Italian agricultural district

Ecophysiological biomarkers and atmospheric contamination due to glyphosate and trace elements were monitored in a southern Italian agricultural district by means of transplanted thalli of the lichen Pseudevernia furfuracea. Glyphosate exhibited a significant geographical pattern (east side > west side) and a drift source area equal to 32% of the monitoring sites. Moreover, based on the surface area of the study area and a wind quantitative relationship (WQR) with glyphosate thalli concentrations, our data support the idea that pesticide drift extends over an area of several square kilometers. Of the eight elements preliminarily classified as enriched, four were considered prevalently of geogenic origin (Al, Ti, Ni, Co) and four of anthropogenic origin (Cu, Mn, Sn, Sb), although only Sb and Cu passed rigorous statistical testing supporting a real difference from pre-exposure levels. The contribution of local sources was evaluated based on the relative increase of Cu, Mn, Sb, and Sn versus Ti. Cu and Mn were associated mainly with a biomass power plant (BPP), with Cu showing extremely high levels of contamination involving 20% of the monitoring sites. Sb and Sn were associated with spatial variation of the traffic rate. The mycobiont and photobiont showed an evident zonation of the levels of their physiological parameters, with oxidative stress being significantly associated with both the biomass power plant and Cu/Ti. Our results suggest that croplands are potentially exposed to various hazards: over-exposure to pesticides due to drift processes, diffuse low traffic levels promoting Sb enrichment, and acute Cu pollution affected by BPP emissions.

Physiological response of two varieties of the lichen Pseudevernia furfuracea to atmospheric pollution

In this work, we studied the physiological response of the two varieties of the lichen Pseudevernia furfuracea (L.) Zopf. exposed in coastal urban areas to a gradient of atmospheric pollutants. The two varieties were compared with respect to the photosynthetic apparatus functioning of the photobiont. Lichen chlorophyll a fluorescence was measured weekly for one month by means of Handy PEA fluorimeter. OJIP fluorescence transient and its derived parameters were evaluated as biomarkers of air pollution in the survey areas. This work supports the use of fluorescence parameters as a reliable tool for assessing the effects of pollutants. However, we highlighted that the responses of the two varieties to pollutants were different and modulated over time. We observed that the photosynthetic efficiency of the algal partner of var. ceratea showed a gradient from the unpolluted to the high-polluted site (unpolluted > low-polluted > high-polluted). Differently, var. furfuracea showed a deep decreasing of photosynthetic efficiency only in the high-polluted site. Our results evidenced that var. ceratea is more sensitive to a gradient of pollution, whereas the photobiont of var. furfuracea is less susceptible in an intermediate condition of pollution.