Examinando por Autor "Barreno, Eva"

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Lichen Biodiversity and Near-Infrared Metabolomic Fingerprint as Diagnostic and Prognostic Complementary Tools for Biomonitoring: A Case Study in the Eastern Iberian Peninsula
(MDPI, 2023-10-31) Moya, Patricia; Chiva, Salvador; Catalá, Myriam; Garmendia, Alfonso; Casale, Monica; Gomez, Jose; Pazos, Tamara; Giordani, Paolo; Calatayud, Vicent; Barreno, Eva
In the 1990s, a sampling network for the biomonitoring of forests using epiphytic lichen diversity was established in the eastern Iberian Peninsula. This area registered air pollution impacts by winds from the Andorra thermal power plant, as well as from photo-oxidants and nitrogen depositions from local and long-distance transport. In 1997, an assessment of the state of lichen communities was carried out by calculating the Index of Atmospheric Purity. In addition, visible symptoms of morphological injury were recorded in nine macrolichens pre-selected by the speed of symptom evolution and their wide distribution in the territory. The thermal power plant has been closed and inactive since 2020. During 2022, almost 25 years later, seven stations of this previously established biomonitoring were revaluated. To compare the results obtained in 1997 and 2022, the same methodology was used, and data from air quality stations were included. We tested if, by integrating innovative methodologies (NIRS) into biomonitoring tools, it is possible to render an integrated response. The results displayed a general decrease in biodiversity in several of the sampling plots and a generalised increase in damage symptoms in the target lichen species studied in 1997, which seem to be the consequence of a multifactorial response.
Symbiotic interactions in the lichen Ramalina farinacea dramatically modify NO biosynthetic source in Trebouxia microalgae
(Elsevier, 2023) Expósito, Joana R.; Barreno, Eva; Catalá, Myriam
NO is a multifaceted molecule, key in functions such as abiotic stress tolerance and symbioses establishment and permanence. Lichens are complex symbiotic associations of microalgae, fungi and prokaryotes that release NO under stress conditions such as dessication-rehydration cycles and the presence of xenobiotics. NO synthase (NOS) oxidises L-arginine to produce NO in animals and some aquatic microalgae, while nitrate reductase (NR) reduces nitrate to NO in plants and fungi. Inhibition studies suggest that both activities might be present in thalli. Due to its multipartner compotition, our hypothesis is that Ramalina farinacea biosynthesises NO through both oxidative (NOS) and reductive (NR) enzymatic pathways. NR activity was quantified with a method optimised for lichens using NADH or/and NADPH, and NOS with a commercial kit in R. farinacea thalli and cultures of the isolated main symbionts: R. farinacea mycobiont, and Trebouxia jamesii and Trebouxia lynnae phycobionts. Inhibition studies in vitro were performed with L-NAME and tungstate. Immunodetection was carried out with specific polyclonal antibodies (anti-plant NADH-NR and anti-iNOS animal isoform). NADH-NR specific activity of R. farinacea is an order of magnitude higher than Arabidopsis thaliana’s and in the range of the chlorophyte Ulva intestinalis. R. farinacea mycobiont possesses a canonical plant-like Moco-NR, while Trebouxia phycobionts’ NR activity presents interesting peculiarities. NOS has not been immunodetected and NOS-like activity is inhibited by L-NAME only partially in T. jamesii. Despite NOS-like activity is very high in the isolated microalgae and fungus, it is strongly depressed in the holobiont. In summary, NR activity seems to be the main source of NO biosynthesis for the holobiont R. farinacea but it presents intriguing features that deserve further study.