Biomonitoring of metal deposition in northern Spain by moss analysis

The results of the first survey carried out in northern Spain to determine atmospheric deposition of metals by analysis of terrestrial mosses, are described. Samples of different mosses, mainly Hypnum cupressiforme and Scleropodium purum, were collected from 134 sampling sites, between 1995 and 1996. Levels of Al, As, Cr, Cu, Fe, Hg, Ni, Pb and Zn, were determined by flame atomic absorption or atomic fluorescence spectrophotometry. Regression analysis was used to compare the capacity of the selected moss species to accumulate the elements, and intercalibration of accumulation in these species was carried out where necessary. Distribution maps were prepared to allow the zones most affected by metal deposition to be identified and to relate this to known sources of contamination: electricity power stations and other industries (e.g. Hg and Ni), edaphic contamination (e.g. Al and Cr) and road traffic (Pb). Background levels of metals in each species were also determined for the study area

A field portable method for the semi-quantitative estimation of dehydration tolerance of photosynthetic tissues across distantly related land plants.

Preprint sustituido por postprint 9-12-2019Desiccation tolerant (DT) plants withstand complete cellular dehydration (reaching relative water contents below 30% in their photosynthetic tissues), while desiccation sensitive (DS) plants exhibit different degrees of dehydration tolerance (DHT), never surviving water loss >70%. To date, no procedure for the quantitative evaluation of DHT extent exists that is able to discriminate DS species with different degrees of DHT from truly DT plants. We developed a simple, feasible, and portable protocol to differentiate between constitutive DT and different degrees of DHT in photosynthetic tissues. The protocol is based on (i) controlled desiccation inside Falcon tubes equilibrated at three different relative humidities (RH: 80%, 50% and <10%) and (ii) evaluation of the average recovery level of maximal photochemical efficiency (Fv/Fm) after rehydration. Applying the method to 10 bryophytes and 28 tracheophytes from various locations, we found that (i) imbibition of absorbent material with saturated salt solutions inside the tubes provides stable RH and avoids direct contact with samples; (ii) for 50 mL capacity tubes, the optimal initial plant amount is 50–200 mg FW; (iii) the tubes can be re-used up to three times with very little changes in RH; (iv) the method is useful in remote locations due to minimal instrumental requirements; (v) a threshold of 30% recovery of the initial Fv/Fm correctly categorises DT species with a few exceptions among tracheophytes: poikilochorophyllous DT-species and some DS herbs and gymnosperms. The protocol provides a semi-quantitative expression of DHT that facilitates comparisons of species with different morpho-physiological traits and/or ecological attributes.Basque Government (UPV/EHU IT-1018-16); Spanish Ministry of Economy and Competitiveness (MINECO) and the ERDF (FEDER) (CTM2014-53902-C2-2-P to JIGP and BFM, CGL2014-54127-P to ENO and JMA, and CTM2014-53902-C2-1-P to JF and JG); Juan de la Cierva-Incorporation fellowship IJCI-2014-22489 to BFM and Juan de la Cierva-Formación FPDI-2013-18167 and FPDI-2013-17135 to MJCM and JoG respectively); MC was supported by a predoctoral fellowship FPI/1700/2014 from the Conselleria d’Educació, Cultura i Universitats (Govern de les Illes Balears) and ESF; MN was supported by a predoctoral fellowship BES-2015-072578 from the Spanish Ministry of Economy and Competitiveness (MINECO) co-financed by the ESF. APC was supported by Spanish Ministry of Education, Culture and Sport (MECD) fellowship (FPU15/02054). MLP was supported by a pre-doctoral grant from the Basque Government. Authors also wish to thank for giving access to the living plant collection of the Royal Botanic Garden Edinburgh. Jill M. Farrant acknowledges funding from the South African Department of Science and Technology and National Research Foundation (grant number 98406

The importance and direction of current and future plant-UV research : break-out session discussions at the UV4Plants Network Meeting in Bled (April 15th -18th , 2018)

During the 2nd Network Meeting of UV4Plants at Bled (14th–18th April, 2018) the delegates engaged in a group discussion of prescient questions concerning the future of in plant-UV research. The discussion group was tasked to identify the most valuable directions for plant UV research to take, and to create a coherent framework for how to move the field forward. Here, the outcome of these discussions is summarised in sections that follow the composition of discussion groups as ideas taken from a molecular, biochemical and physiological perspective followed by those from an ecological and plant production perspective. In each case, first basic research questions are considered and then applications and methodological considerations are put forward. Finally, some common ground bringing the two perspectives together is discussed, with the aim of solving scaling problems and ways in which the UV4Plants network might be put to good use.Peer reviewe

A perspective on ecologically relevant plant-UV research and its practical application

Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.Peer reviewe

Age-specific physiological responses to UV radiation in the aquatic liverwort &lt;I&gt;Jungermannia exsertifolia&lt;/I&gt; subsp. &lt;I&gt;cordifolia&lt;/I&gt;

In the UV-tolerant aquatic liverwort Jungermannia exsertifolia Steph. subsp. cordifolia (Dumort.) Váña, increased accumulation of certain hydroxycinnamoylmalic acid (HCM acid) derivatives has been observed under natural and artificial increases of UV radiation. We hypothesized that, under an artificial UV enhancement, the newly grown shoot apices would develop more physiological protection against UV radiation than the basal old parts.Both the UV increase and the tissue age affected the distribution of HCM acid derivatives after 82 days of culture. Two coumarins (5U-(7U,8U-dihydroxycoumaroyl)-2-caffeoylmalic acid, and its glucosyl derivative) significantly increased under the UV treatment, but their distribution between the apical and basal parts were opposite, where the former was more concentrated in the apical segments and the latter in the basal segments. p-Coumaroylmalic acid also showed a significant increase due to UV, and increased by the same proportion in both types of segments. In contrast, the main compound phaselic acid decreased in the apical parts under UV, whereas feruloylmalic acid only accumulated in the basal parts under UV. Physiological variables indicative of vitality, such as the maximum quantum yield of PSII (Fv/Fm) and chlorophyll concentration, did not show any damage caused by the UV enhancement in the liverwort studied. The different distribution of the abovementioned compounds between apical and basal parts - together with the increase of carotenoids in the UV treatment - may indicate changes in metabolic pathways to increase photoprotection in young apical shoots.</p

Brioflora del río Iregua (La Rioja, España)

Presentamos un catálogo de la brioflora del río Iregua (La Rioja, España) compuesto por 123 táxones, 40 hepáticas y 83 musgos. Bryum barnesii Wood in Schimp. es nuevo para España, 8 taxones más son nuevos para el sistema Ibérico, y 24 más para la Rioja. Analizamos la riqueza específica de las 60 localidades muestreadas, y las agrupamos mediante el índice de afinidad de Jaccard. Discutimos los tipos de reproducción observados, la frecuencia de las especies y algunos aspectos evolutivos. Summary: The catalogue of the bryoflora of Iregua river (La Rioja, Spain), is composed of 123 taxa. Bryum barnesii is a new record for Spain, 8 taxa are new for the Iberian System, and 24 for La Rioja. Species richness of the 60 sampled localities is analysed and Jaccard´s affinity index used. Reproductive trends, frequency and some evolutive aspects of the collected species are discussed

Brioflora del piso de marojal de la Sierra de Cameros

Presentamos un Catálogo de Briofitos en el que recogemos 136 taxones, 100 de Musgos y 36 de Hepáticas. Son nuevas para el Catálogo Briológico de La Rioja 31 especies y 3 variedades. De ellas, 14 especies son nuevas para el Sistema Ibérico, y 7 no lo son para el Sistema Ibérico Septentrional. Se cita por segunda vez para España Mnium lycopodioides Schwaegr.; por tercera vez Zygodon forsteri (With.) Mitt.; y Saelania glaucescens (Hedw.) Broth. se cita por primera vez fuera de los Pirineos y el Montseny. El elemento corológico Circumboreal domina en la zona estudiada (59,7%), seguido del Atlántico, Cosmopolita y Mediterráneo (17,2-15,7 y 7,4%, respectivamente). Summary: We have studied the Bryophytes of the Sierra de Cameros (La Rioja). We have collected 131 species and 5 varieties; 34 of them are new for the province; 14 species are new for the Sistema Ibérico, and 7 more ones are new for the northern area of that chain of mountains. We´ve collected Mnium lycopodioides Schwaegr. for the second time in Spain; Zygodon forsteri (With.) Mitt. for the third time, and we enlarge the distribution area of Saelania glaucescens, only collected before in the Pirineos and Montseny. The most representative species of our area are those of circumboreal distribution (59,7%)

Weaker photosynthetic acclimation to fluctuating than to corresponding steady UVB radiation treatments in grapevines

The effects of transient increases in UVB radiation on plants are not well known; whether cumulative damage dominates or, alternately, an increase in photoprotection and recovery periods ameliorates any negative effects. We investigated photosynthetic capacity and metabolite accumulation of grapevines (Vitis vinifera Cabernet Sauvignon) in response to UVB fluctuations under four treatments: fluctuating UVB (FUV) and steady UVB radiation (SUV) at similar total biologically effective UVB dose (2.12 and 2.23 kJ m−2 day−1), and their two respective no UVB controls. We found a greater decrease in stomatal conductance under SUV than FUV. There was no decrease in maximum yield of photosystem II (Fv/Fm) or its operational efficiency (ɸPSII) under the two UVB treatments, and Fv/Fm was higher under SUV than FUV. Photosynthetic capacity was enhanced under FUV in the light‐limited region of rapid light‐response curves but enhanced by SUV in the light‐saturated region. Flavonol content was similarly increased by both UVB treatments. We conclude that, while both FUV and SUV effectively stimulate acclimation to UVB radiation at realistic doses, FUV confers weaker acclimation than SUV. This implies that recovery periods between transient increases in UVB radiation reduce UVB acclimation, compared to an equivalent dose of UVB provided continuously. Thus, caution is needed in interpreting the findings of experiments using steady UVB radiation treatments to infer effects in natural environments, as the stimulatory effect of steady UVB is greater than that of the equivalent fluctuating UVB

Environmental factors correlated with the metabolite profile of Vitis vinifera cv. Pinot noir berry skins along a european latitudinal gradient

Mature berries of Pinot Noir grapevines were sampled across a latitudinal gradient in Europe, from southern Spain to central Germany. Our aim was to study the influence of latitude-dependent environmental factors on the metabolite composition (mainly phenolic compounds) of berry skins. Solar radiation variables were positively correlated with flavonols and flavanonols and, to a lesser extent, with stilbenes and cinnamic acids. The daily means of global and erythematic UV solar radiation over long periods (bud break-veraison, bud break-harvest, and veraison-harvest), and the doses and daily means in shorter development periods (5-10 days before veraison and harvest) were the variables best correlated with the phenolic profile. The ratio between trihydroxylated and monohydroxylated flavonols, which was positively correlated with antioxidant capacity, was the berry skin variable best correlated with those radiation variables. Total flavanols and total anthocyanins did not show any correlation with radiation variables. Air temperature, degree days, rainfall, and aridity indices showed fewer correlations with metabolite contents than radiation. Moreover, the latter correlations were restricted to the period veraison-harvest, where radiation, temperature, and water availability variables were correlated, making it difficult to separate the possible individual effects of each type of variable. The data show that managing environmental factors, in particular global and UV radiation, through cultural practices during specific development periods, can be useful to promote the synthesis of valuable nutraceuticals and metabolites that influence wine quality

UV responses of Lolium perenne raised along a latitudinal gradient across Europe: a filtration study

Lolium perenne (cv. AberDart) was grown at 14 locations along a latitudinal gradient across Europe (3768 degrees N) to study the impact of ultraviolet radiation (UV) and climate on aboveground growth and foliar UV-B absorbing compounds. At each location, plants were grown outdoors for 5 weeks in a replicated UV-B filtration experiment consisting of open, UV-B transparent (cellulose diacetate) and UV-B opaque (polyester) environments. Fourier transform-infrared spectroscopy was used to compare plant metabolite profiles in relation to treatment and location. UV radiation and climatic parameters were determined for each location from online sources and the data were assessed using a combination of anova and multiple regression analyses. Most of the variation in growth between the locations was attributable to the combination of climatic parameters, with minimum temperature identified as an important growth constraint. However, no single environmental parameter could consistently account for the variability in plant growth. Concentrations of foliar UV-B absorbing compounds showed a positive trend with solar UV across the latitudinal gradient; however, this relationship was not consistent in all treatments. The most striking experimental outcome from this study was the effect of presence or absence of filtration frames on UV-absorbing compounds. Overall, the study demonstrates the value of an European approach in studying the impacts of natural UV across a large latitudinal gradient. We have shown the feasibility of coordinated UV filtration at multiple sites but have also highlighted the need for open controls and careful interpretation of plant responses