Effects of industrial pollution and ambient air temperature on larval performance and population dynamics of Eriocrania leafminers (Lepidoptera).

Pollution is an integral part of global environmental change, yet the combined and interactive effects of pollution and climate on terrestrial ecosystems remain inadequately understood. This study aims to explore whether pollution alters the impacts of ambient air temperature on the population dynamics of herbivorous insects. Between 1995 and 2005, we studied populations of two closely related moths, Eriocrania semipurpurella and E. sangii, at eight sites located 1 to 64 km from a large copper­nickel smelter in Monchegorsk, Russia. We found that pollution and temperature influence the performance of Eriocrania larvae mining in the leaves of mountain birch, Betula pubescens var. pumila, through multiple pathways. This is evident from the unconsistent changes observed in larval and frass weight, mine area, and leaf size. We found increases in both leaf quality and larval weight with decreasing pollution levels at both spatial and temporal scales and attributed these to the impact of sulphur dioxide, rather than trace elements (nickel and copper). The quality of birch leaves increased with spring (May) temperatures, enabling Eriocrania larvae to achieve greater weight while consuming less biomass. During the larval growth period (early June to early July), Eriocrania larvae increased their consumption with rising temperatures, presumably to compensate for increased metabolic expenses. Contrary to our expectations, the per capita rate of population change did not correlate with larval weight and did not vary along the pollution gradient. Nevertheless, we detected interactive effects of pollution and climate on the rate of population change. This rate decreased with rising winter temperatures in slightly polluted and unpolluted sites but remained unchanged in heavily polluted sites. We conclude that pollution disrupts mechanisms regulating the natural population dynamics of Eriocrania moths.

Filsuvez® gel (Oleogel-S10) para epidermólisis bullosa / Filsuvez® gel (Oleogel-S10) for epidermolysis bullosa

INTRODUCCIÓN: La epidermólisis bullosa o ampollosa es un grupo heterogéneo de enfermedades mecanoampollosas genéticas autosómicas, dominantes o recesivas, caracterizadas por diversos grados de fragilidad de la piel y las mucosas causada por mutaciones que afectan las proteínas estructurales de la piel. Se han descripto cuatro tipos principales de epidermólisis bullosa, según el nivel estructural de división del tejido en la piel: epidermólisis bullosa simple, de la unión, distrófica y de Kindler. La gravedad de la enfermedad está determinada por el nivel de ampollas y el tipo de mutación y es muy variable entre los subtipos. La epidermólisis bullosa simple es autosómica dominante de separación intraepidérmica, con ampollas con trauma leve que curan sin dejar cicatriz y suele presentarse al nacer o en la primera infancia y de curso crónico, pero la formación de ampollas tiende a disminuir con la edad. La de la unión es autosómica recesiva de separación intra-lamina lucida, es la variante más grave, con muerte prematura en la infancia debido a la desnutrición o infecciones, y se caracteriza por ampollas y erosiones generalizadas con tejido de granulación que no cicatriza; asociado con uñas ausentes, dientes displásicos, lesiones orales y estenosis pilórica. La distrófica es autosómica recesiva y dominante de separación de láminas sub-basales y suele comenzar al nacer, con ampollas generalizadas que curan con cicatrices extensas que traen un riesgo de presentar secuelas graves y con muerte en la edad adulta temprana por las complicaciones. Finalmente, la Kindler es autosómica recesiva de separación a nivel de los queratinocitos basales o de lámina sub-basal, con ampollas inducidas por traumatismos leves que pueden disminuir con la edad. El manejo de los pacientes con epidermólisis bullosa es principalmente de apoyo e incluye el cuidado de heridas y la prevención y tratamiento de complicaciones (control del dolor, nutrición, cuidado de lesiones extra-cutáneas, etc.) involucrando a un equipo multidisciplinario de profesionales, donde en la actualidad no existe una terapia dirigida para la epidermólisis bullosa. TECNOLOGÍA: Oleogel-S10 (Filsuvez®) es un gel cicatrizante que contiene extracto seco de la corteza de Betulae (corteza de abedul), también conocido como extracto triterpénico. El gel contiene 90% peso/peso de aceite de girasol y 10% peso/peso de extracto seco de corteza de abedul, de los cuales la mayoría es betulina (72 a 88% peso/peso). Las sustancias marcadoras activas adicionales incluyen ácido betulínico, lupeol, ácido oleanólico y eritrodiol. OBJETIVO: El objetivo del presente informe es evaluar rápidamente los parámetros de eficacia, seguridad, costos y recomendaciones disponibles acerca del empleo de Filsuvez® gel (Oleogel-S10) para el tratamiento de la epidermólisis bullosa. MÉTODOS: Se realizó una búsqueda bibliográfica en las principales bases de datos tales como PUBMED, LILACS, BRISA, COCHRANE, SCIELO, EMBASE, TRIPDATABASE como así también en sociedades científicas, agencias reguladoras, financiadores de salud y agencias de evaluación de tecnologías sanitarias. Se priorizó la inclusión de revisiones sistemáticas, ensayos clínicos controlados aleatorizados, evaluación de tecnología sanitaria y guías de práctica clínica de alta calidad metodológica. En PubMed se utilizó la estrategia de búsqueda que se detalla en el Anexo I. La fecha de búsqueda de información fue hasta el 01 de noviembre de 2022. Para la búsqueda en Pubmed se utilizó la siguiente estrategia de búsqueda: ((Filsuvez[tiab] OR Oleogel-S10[tiab] OR birch bark extract[tiab]) AND (Epidermolysis Bullosa[MeSH] OR Acantholysis Bullosa[tiab])). RECOMENDACIONES: No se hallaron guías de práctica clínica actualizadas en Argentina y en el Mundo que mencionen la tecnología en la indicación evaluada. El Instituto Nacional para la Excelencia en Salud y Atención (NICE su sigla del inglés, National Institute for Health and Care Excellence) de Reino Unido y la Agencia Canadiense de Medicamentos y Tecnologías en Salud (CADTH su sigla del inglés, Canadian Agency for Drugs & Technologies in Health) no han evaluado al tratamiento en la indicación evaluada. CONCLUSIONES: La evidencia que sustenta la aprobación de comercialización de Oleogel-S10 (Filsuvez®) para el tratamiento de heridas de espesor parcial asociadas con epidermólisis bullosa en personas a partir de los 6 meses de edad, se basa en un estudio clínico con resultados aún no publicados con control de pares. Este estudio demostraría que en personas sin complicaciones, el OleogelS10 sumado al cuidado estándar aumentaría la proporción de personas con cierre completo de la herida en personas con epidermólisis bullosa distrófica de herencia recesiva frente a placebo al corto plazo. No se observarían beneficios en personas con epidermólisis bullosa de la unión o con distrófica de herencia dominante, como tampoco para otros desenlaces. Los eventos adversos reportados más comunes fueron las complicaciones de heridas, reacciones en el lugar de aplicación, infecciones de heridas, prurito y reacciones de hipersensibilidad. La agencia regulatoria de los Estados Unidos todavía no ha autorizado su comercialización; mientras que la agencia europea la ha autorizado recientemente, junto con la designación de medicamento huérfano, para el tratamiento de heridas de espesor parcial asociadas con epidermólisis bullosa distrófica y de la unión en personas a partir de los 6 meses de edad. No se hallaron guías de práctica clínica actualizadas en Argentina y en el Mundo que mencionen la tecnología en la indicación evaluada. No se hallaron evaluaciones económicas publicadas, como tampoco precios de adquisición de referencia en el Mundo.

Cascading effects of moth outbreaks on subarctic soil food webs.

The increasing severity and frequency of natural disturbances requires a better understanding of their effects on all compartments of biodiversity. In Northern Fennoscandia, recent large-scale moth outbreaks have led to an abrupt change in plant communities from birch forests dominated by dwarf shrubs to grass-dominated systems. However, the indirect effects on the belowground compartment remained unclear. Here, we combined eDNA surveys of multiple trophic groups with network analyses to demonstrate that moth defoliation has far-reaching consequences on soil food webs. Following this disturbance, diversity and relative abundance of certain trophic groups declined (e.g., ectomycorrhizal fungi), while many others expanded (e.g., bacterivores and omnivores) making soil food webs more diverse and structurally different. Overall, the direct and indirect consequences of moth outbreaks increased belowground diversity at different trophic levels. Our results highlight that a holistic view of ecosystems improves our understanding of cascading effects of major disturbances on soil food webs.

Effect of Drought and Heavy Metal Contamination on Growth and Photosynthesis of Silver Birch Trees Growing on Post-Industrial Heaps.

Silver birch trees (Betula pendula Roth) are a pioneering species in post-industrial habitats, and have been associated with an expansive breeding strategy and low habitat requirements. We conducted ecophysiological and dendroclimatological studies to check whether there are any features of which the modification enables birch trees to colonise extreme habitats successfully. We characterised the efficiency of the photosynthetic apparatus, the gas exchange, the content of pigments in leaves, and the growth (leaf thickness and tree-ring width) of birch trees on a post-coal mine heap, a post-smelter heap, and a reference site. Birch growth was limited mainly by temperature and water availability during summer, and the leaves of the birch growing on post-industrial heaps were significantly thicker than the reference leaves. Moreover, birch trees growing on heaps were characterised by a significantly higher content of flavonols and anthocyanins in leaves and higher non-photochemical quenching. In addition, birches growing on the post-coal mine heap accumulated a concentration of Mn in their leaves, which is highly toxic for most plant species. Increasing the thickness of leaves, and the content of flavonols and anthocyanins, as well as efficient non-photochemical quenching seem to be important features that improve the colonization of extreme habitats by birches.

Identification and characterization of cadmium stress-related LncRNAs from Betula platyphylla.

Cadmium (Cd) is one of the most serious global environmental pollutants, which inhibits plant growth and interferes with their physiological processes. However, there have been few studies on the involvement of long noncoding RNAs (lncRNAs) in Cd tolerance. In the present study, we identified the lncRNAs from Betula platyphylla (birch) that respond to Cd stress. Thirty lncRNAs that were differentially expressed under Cd treatment were identified, including 16 upregulated and 14 downregulated lncRNAs. Nine differentially regulated lncRNAs were selected for further characterization. These lncRNAs were transiently overexpressed in birch plants to determine their roles in Cd tolerance. Among them, two lncRNAs conferred Cd tolerance and two induced sensitivity to Cd stress. We further determined the Cd tolerance of four target genes of the lncRNAs involved in Cd tolerance, including l-lactate dehydrogenase A (LDHA),heat shock protein (HSP18.1), yellow stripe-like protein (YSL9), and H/ACA ribonucleoprotein complex subunit 2-like protein (HRCS2L). Among them, HSP18.1 and LDHA showed improved tolerance to Cd stress, whereas the other two genes did not appear to be involved in Cd tolerance. These results suggested that lncRNAs can up- or downregulate their target genes to improve Cd tolerance. These results increase our understanding of lncRNA-mediated Cd tolerance.

Expression characteristics and function of CAS and a new beta-amyrin synthase in triterpenoid synthesis in birch (Betula platyphylla Suk.).

Triterpenoids produced by the secondary metabolism of Betula platyphylla Suk. exhibit important pharmacological activities, such as tumor inhibition, anti-HIV, and defense against pathogens, but the yield of natural synthesis is low, which is insufficient to meet people's needs. In this study, we identified two OSC genes of birch, named as BpCAS and Bpß-AS, respectively. The expression of BpCAS and Bpß-AS were higher levels in roots and in stems, respectively, and they induced expression in response to methyl jasmonate (MeJA), gibberellin (GA3), abscisic acid (ABA), ethylene and mechanical damage. The function of the two genes in the triterpene synthesis of birch was identified by reverse genetics. The inhibition of Bpß-AS gene positively regulates synthesis of betulinic acid. BpCAS interference can significantly promote the upregulation of lupeol synthase gene (BPW) and ß-amyrin synthase gene(BPY), and conversion of 2,3-oxidosqualene to the downstream products betulinic acid and oleanolic acid. This study provided a basis for the genetic improvement of triterpenoid synthesis in birch through genetic engineering. The obtained transgenic birch and suspension cells served as material resources for birch triterpenoid applications in further.

Wetland macrophyte community response to and recovery from direct application of glyphosate-based herbicides.

Community-scale impacts of glyphosate-based herbicides on wetland plant communities and the magnitude of those impacts that should be considered biologically relevant are poorly understood. We contrast three different thresholds for setting biologically meaningful critical effect sizes for complex ANOVA study designs. We use each of the of the critical effect sizes to determine optimal α levels for assessment of how different concentrations of glyphosate-based herbicides affect wetland plant communities over two years of herbicide application (alone and in combination with agricultural fertilizers) and two subsequent years without herbicide (or fertilizer) application. The application of glyphosate-based herbicides was found to result in a decrease in macrophyte species richness, an increase in macrophyte species evenness, a decrease in macrophyte cover and a reduction in community similarity. There was little evidence that nutrient additions directly or indirectly affected plant community endpoints. The glyphosate effects were evident in the first year of herbicide application in 2009, and became more pronounced in the second year of herbicide application in 2010. However, when herbicides were not applied in 2011, recovery was observed in most endpoints, with the exception being species evenness, for which partial recovery was not observed until 2012. Optimal α levels differed among the three critical effect sizes for each ANOVA term and endpoint combination, however regardless of differences in α levels, conclusions were generally consistent across all critical effect sizes.

Abscisic acid promotes root system development in birch tissue culture: a comparison to aspen culture and conventional rooting-related growth regulators.

The research aim was to assess the effects of the plant hormone abscisic acid (ABA) and the growth regulator paclobutrazol (PBZ) on root system development during the in vitro culture of different birch and aspen genotypes. The studied genotypes involved two aspen (Populus tremula and Populus tremuloides × P. tremula) and two silver birch (Betula pendula) trees, with one of the birches characterized by its inability to root in vitro. For experiments, apical shoot segments were cultured on nutrient medium enriched with either ABA or PBZ. Additionally, the analysis of the endogenous hormones in shoots developed on hormone-free medium was conducted by high-performance liquid chromatography. The endogenous concentration of auxin indole-3-acetic acid was much higher in the aspens than that in the birches, while the highest concentration of ABA was found in the root-forming birch. The culturing of this birch genotype on medium enriched with ABA resulted in an increased root length and a higher number of lateral roots without any negative effect on either shoot growth or adventitious root (AR) formation, although these two processes were largely inhibited by ABA in the aspens. Meanwhile, PBZ promoted AR formation in both aspen and birch cultures but impaired secondary root formation and shoot growth in birches. These results suggest the use of ABA for the in vitro rooting of birches and PBZ for the rooting of aspens.

Improved accumulation of betulin and betulinic acid in cell suspension culture of Betula pendula roth by abiotic and biotic elicitors.

Betulin (B) and betulinic acid (BA) are two triterpenes with diverse pharmacological and physiological actions. Elicitation of Betula pendula Roth cell cultures by elicitors is an excellent strategy to increase B and BA levels. Six abiotic and biotic elicitors were studied to improve accumulation of B and BA in the cell culture of B. pendula. The B and BA production in treated cells was verified by HPLC. The results showed the maximum growth index (7) on day 3 in cells treated with 0.5 mg L-1 chlorocholine chloride (CCC). The increased accumulation of BA in the cells treated with 200 mg L-1 of chitosan was found to be 5.9 × (6.5 mg g-1 DW) higher over control cells. Treating the cells with 2 mg L-1 of CCC, after 7 days, led to 149.3× enhancement of B content (19.4 mg g-1 DW) over the controls. Production of this triterpenoid at a much shorter time with a much higher growth rate can be economic and lead to producing large amounts of B and BA for anti-cancer and HIV drugs preparation.

Uptake of ozone and modification of lipids in Betula Pendula pollen.

Pollen allergy risk is modified by air pollutants, including ozone, but the chemical modifications induced on pollen grains are poorly understood. Pollen lipidic extract has been shown to act as an adjuvant to the allergenic reaction and therefore, the modification of lipids by air pollutants could have health implications. Birch pollen was exposed in vitro to ozone to explore the reactivity of O3 on its surface and on its lipidic fraction. Uptake coefficients of ozone were determined for ozone concentration of 117 ppb on the surface of native birch pollen (8.6 ±â€¯0.8 × 10-6), defatted pollen (9.9 ±â€¯0.9 × 10-6), and for crushed pollen grains (34±3 × 10-6). The mass of ozone uptaken was increased by a factor of four for crushed pollen compared to native pollen showing a higher susceptibility to ozone of cytoplasmic granules and broken pollen grains. A total mass of extractible lipids of 27 mg per gram of birch pollen was found and a fraction of these lipids was identified and quantified (fatty acids, alkanes, alkenes and aldehydes). The distribution of lipids was modified by ozone exposure of 115 and 1000 ppb for 16 h with the following reactivity: consumption of alkene, formation of aldehydes and formation of nonanoic acid and octadecanoic acid. The quantity of ozone trapped in the lipidic fraction during 15 min at 115 ppb is enough to contribute to the reactivity of one-third of the alkenes demonstrating that pollen could be susceptible to an atmospheric increase of ozone concentration even for a very short duration complicating the understanding of the link between pollen allergy and pollution.

Maintenance of photosynthesis by Betula populifolia in metal contaminated soils.

Improving our understanding of plant responses to elevated trace metal concentrations under field conditions will enhance restoration and urban greening practices in settings with contaminated soils. This study examined the effects of trace metal pollution on the leaf gas exchange rates of mature, field-grown Betula populifolia Marsh. (gray birch) trees, additionally assessing whether elevated temperature and drought compounded the effects of trace metal contamination. The study compared B. populifolia growing in areas of comparatively high and low trace metal loads (HML and LML, respectively) within a former rail yard at Liberty State Park in Jersey City, New Jersey, USA. Gas exchange parameters were determined monthly from May through September in 2014 and 2015 using a portable photosynthesis system. The effects of drought and high temperature were assessed during a short heat wave in July 2015 and via a manipulative experiment, respectively. During a few of the measurement months, some parameters differed significantly between the LML and HML groups. However, when considered over the entire study period, no significant differences in biophysical parameters were observed between groups. The photosynthetic capacity of B. populifolia thus appears to be fairly robust across this site's steep gradient of trace metal contamination. Nonetheless, leaf mass per unit area was significantly lower in the HML group, indicating that metal loads affected resource allocation within trees. Also, immediately following the heat wave in 2015, intrinsic water use efficiency declined significantly in the HML group, suggesting that extreme climatic conditions can have a disproportionate effect on the physiological performance of plants growing in metal contaminated soils.

Methyl salicylate differently affects benzenoid and terpenoid volatile emissions in Betula pendula.

Methyl salicylate (MeSA) is a long-distance signal transduction chemical that plays an important role in plant responses to abiotic stress and herbivore and pathogen attacks. However, it is unclear how photosynthesis and elicitation of plant volatile organic compounds (VOC) from different metabolic pathways respond to the dose of MeSA. We applied different MeSA concentrations (0-50 mM) to study how exogenous MeSA alters VOC profiles of silver birch (Betula pendula Roth) leaves from application through recovery (0.5-23 h). Methyl salicylate application significantly reduced net assimilation rate in 10 mM and 20 mM MeSA-treated plants. No significant effects of MeSA were observed on the stomatal conductance at any MeSA concentration. Methyl salicylate elicited emissions of benzenoids (BZ), monoterpenes (MT) and fatty acid derived compounds (LOX products). Emission rates of BZ were positively, but emission rates of MT were negatively correlated with MeSA concentration. Total emission of LOX products was not influenced by MeSA concentration. Emission rate of MT was negatively correlated with BZ and the share of MT in the total emission blend decreased and the share of BZ increased with increasing MeSA concentration. Although the share of LOX products was similar across MeSA treatments, some LOX products responded differently to MeSA concentration, ultimately resulting in unique VOC blends. Overall, this study demonstrates inverse responses of MT and BZ to different MeSA doses such that plant defense mechanisms induced by lower MeSA doses mainly lead to enhanced MT synthesis, whereas greater MeSA doses trigger BZ-related defense mechanisms. Our results will contribute to improving the understanding of birch defenses induced upon regular herbivore attacks and pathogen infections in boreal forests.

The effect of cisplatin administration on certain trace elements homeostasis in rats and the protective effect of silver birch (Betula pendula) sap.

BACKGROUND: A clinically active structure with known antitumor activities is cisplatin (CDDP), but this it comes with toxicity characteristics which can be faded by the beneficial effects of Silver birch (Betula pendula) sap. OBJECTIVE: We aimed to assess the cisplatin activity on: Mn, Mg, Cu, Fe and Zn homeostasis in rats and to observe the effect of birch sap. METHODS: Healthy Wistar rats (n = 10/group) were divided in four groups: Control: receiving 1 mL saline I.P. way + water; E1: cisplatin 20 mg kgbw-1, I.P.; E2: cisplatin 20 mg kgbw-1, I.P. + birch sap and Control sap group: 1 mL saline I.P. + birch sap. Blood was collected: at the trial's start and after 48 h, and blood and organs (liver, kidney and spleen) for the cytoarchitecture investigation and readings were sampled after seven days. Samples were processed in nitric acid by microwave digestion and readings were completed by flame atomic absorption spectroscopy, the outcomes being statistically analyzed by ANOVA. RESULTS: Cisplatin produced a significant imbalance in the trace elements homeostasis, the birch sap administration recovering them usual homeostasis status. Comparatively with the Control, rats exposed to cisplatin presented a not significant (p > 0.05) decrease of Zn (-26.74%) and Mg (-10.25%), a significant (p < 0.05) decrease of Cu (-27.73%) at 48 h, a highly significant (p < 0.01) decrease of Cu (-56.08%) and Fe (-85.35%) at seven days after administration and a not significant (p > 0.05) increase of Mn (+28.16%). Birch sap administration after Cisplatin was followed by restoration or nevertheless significant increase (p < 0.05) of the investigated trace elements Zn (+56.88% to 48 h/+89.94% after seven days), Mg (+26.86%/+95.74%), Cu (+23.13%/+74.56%), Fe (+39.64%/+440.11%) and Mn (+4.30%/+15.87%), suggesting them defence against cisplatin. Histology revealed the order of main altered organs after the CDDP exposure: kidney, spleen and liver. CONCLUSIONS: The study recommended the important protective role of Betula pendula sap against diverse cisplatin deleterious side-effects.

Ozone-induced stomatal sluggishness changes stomatal parameters of Jarvis-type model in white birch and deciduous oak.

Stomatal ozone flux is closely related to ozone injury to plants. Jarvis-type multiplicative model has been recommended for estimating stomatal ozone flux in forest trees. Ozone can change stomatal conductance by both stomatal closure and less efficient stomatal control (stomatal sluggishness). However, current Jarvis-type models do not account for these ozone effects on stomatal conductance in forest trees. We examined seasonal course of stomatal conductance in two common deciduous tree species native to northern Japan (white birch: Betula platyphylla var. japonica; deciduous oak: Quercus mongolica var. crispula) grown under free-air ozone exposure. We innovatively considered stomatal sluggishness in the Jarvis-type model using a simple parameter, s, relating to cumulative ozone uptake (defined as POD: phytotoxic ozone dose). We found that ozone decreased stomatal conductance of white birch leaves after full expansion (-28%). However, such a reduction of stomatal conductance by ozone fell in late summer (-10%). At the same time, ozone reduced stomatal sensitivity of white birch to VPD and increased stomatal conductance under low light conditions. In contrast, in deciduous oak, ozone did not clearly change the model parameters. The consideration of both ozone-induced stomatal closure and stomatal sluggishness improved the model performance to estimate stomatal conductance and to explain the dose-response relationship on ozone-induced decline of photosynthesis of white birch. Our results indicate that ozone effects on stomatal conductance (i.e. stomatal closure and stomatal sluggishness) are crucial for modelling studies to determine stomatal response in deciduous trees, especially in species sensitive to ozone.

Mycorrhization protects Betula pubescens Ehr. from metal-induced oxidative stress increasing its tolerance to grow in an industrial polluted soil.

In recent years, the use of woody plants in phytoremediation has gained popularity due to their high biomass production and their association with mycorrhizal fungi, which can improve their survival and development rates under stress conditions. In this study, mycorrhized and non-mycorrhized white birch plants (Betula pubescens Ehr.) were grown in control and a metal-polluted industrial soil. After 60days of culture, plant growth and metal accumulation, the content of photosynthetic pigments and oxidative-stress markers, as well as the enzymatic activities and gene expressions of antioxidant enzymes were measured. According to our results, mycorrhized birch plants grown in control soil showed an increased activity and gene expression of catalase and ascorbate peroxidase, along with hydrogen peroxide overproduction, which could support the importance of the reactive oxygen species as signaling molecules in the regulation of plant-fungus interactions. Additionally, in polluted soil mycorrhized plants had higher biomass but lower metal accumulation, probably because the symbiotic fungus acted as a barrier to the entrance of metals into the host plants. This behavior led to mitigation in the oxidative challenge, reduced hydrogen peroxide content and diminished activities of the antioxidant enzymes in comparison to non-mycorrhized plants.

Leaf traits and photosynthetic responses of Betula pendula saplings to a range of ground-level ozone concentrations at a range of nitrogen loads.

Ground-level ozone (O3) concentrations and atmospheric nitrogen (N) deposition rates have increased strongly since the 1950s. Rising ground-level O3 concentrations and atmospheric N deposition both affect plant physiology and growth, however, impacts have often been studied in isolation rather than in combination. In addition, studies are often limited to a control treatment and one or two elevated levels of ozone and/or nitrogen supply. In the current study, three-year old Betula pendula saplings were exposed to seven different O3 profiles (24h mean O3 concentration of 36-68ppb in 2013, with peaks up to an average of 105ppb) in precision-controlled hemispherical glasshouses (solardomes) and four different N loads (10, 30, 50 or 70kgNha-1y-1) in 2012 and 2013. Here we report on the effects of enhanced O3 concentrations and N load on leaf traits and gas exchange in leaves of varying age and developmental stage in 2013. The response of leaf traits to O3 (but not N) vary with leaf developmental stage. For example, elevated O3 did not affect the chlorophyll content of the youngest fully expanded leaf, but it reduced the chlorophyll content and photosynthetic parameters in aging leaves, relatively more so later than earlier in the growing season. Elevated O3 enhanced the N content of senesced leaves prior to leaf fall, potentially affecting subsequent N cycling in the soil. Enhanced N generally stimulated the chlorophyll content and photosynthetic capacity. Whilst elevated O3 reduced the light-saturated rate of photosynthesis (Asat) in aging leaves, it did not affect stomatal conductance (gs). This suggests that photosynthesis and gs are not closely coupled at elevated O3 under-light saturating conditions. We did not observe any interactions between O3 and N regarding photosynthetic parameters (Vc,max, Jmax, Asat), chlorophyll content, gs, N content in senesced leaves and leaf number. Hence, the sensitivity of these leaf traits to O3 in young silver birch trees is neither reduced nor enhanced by N load.

Formic acid aided hot water extraction of hemicellulose from European silver birch (Betula pendula) sawdust.

Hemicellulose has been extracted from birch (Betula pendula) sawdust by formic acid aided hot water extraction. The maximum amount of hemicellulose extracted was about 70mol% of the total hemicellulose content at 170°C, measured as the combined yield of xylose and furfural. Lower temperatures (130 and 140°C) favored hemicellulose hydrolysis rather than cellulose hydrolysis, even though the total hemicellulose yield was less than at 170°C. It was found that formic acid greatly increased the hydrolysis of hemicellulose to xylose and furfural at the experimental temperatures. The amount of lignin in the extract remained below the detection limit of the analysis (3g/L) in all cases. Formic acid aided hot water extraction is a promising technique for extracting hemicellulose from woody biomass, while leaving a solid residue with low hemicellulose content, which can be delignified to culminate in the three main isolated lignocellulosic fractions: cellulose, hemicellulose, and lignin.

Accumulative response of Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Roth) to heavy metals enhanced by Pb-Zn ore mining and processing plants: Explicitly spatial considerations of ordinary kriging based on a GIS approach.

Plants have an accumulative response to heavy metals present in soils or deposited from airborne sources of emissions. Therefore, their tissues are very often used in studies of heavy metal contamination originating from different sources as a bioindicator of environmental pollution. This research was undertaken to examine accumulation capacities of Pb, Zn, Cd, Cu and Cr in washed and unwashed needles of Scots pine (Pinus sylvestris L.) and leaves of silver birch (Betula pendula Roth) growing in a contaminated area. We collected needles of Scots pine and leaves of silver birch in an area around a sedimentation pond and metallurgic plant processing Pb and Zn ores near Olkusz, Poland. Concentrations of heavy metals, which have been linked with exposure to emissions, were determined from foliar samples collected at 33 sites. These sites were established at various distances (0.5-3.6 km) from the pond and metallurgic plant so as to identify the predominant accumulative response of plants. Spatial gradients for Pb and Zn were calculated using an ordinary kriging interpolation algorithm. A spatial pattern was identified by a GIS method to visualize maps over the Pb-Zn ore mining area. The accumulation of Zn (R2 = 0.74, p < 0.05) and Pb (R2 = 0.85, p < 0.01) in plant tissues correlated with soil concentrations. This tendency was not found in the case of Cu, Cd and Cr.

Evidence of prokaryote like protein associated with nickel resistance in higher plants: horizontal transfer of TonB-dependent receptor/protein in Betula genus or de novo mechanisms?

Mechanisms of metal resistance have been reported in many plants but knowledge in woody species is scarce. The TonB-dependent receptors family (TBDTs) is a large group of proteins that facilitate the transport of molecules across the membrane of Gram-negative bacteria. Some evidence exists that TBDTs are involved in metal stress. The existence of a TonB-like mechanism in non-prokaryotes has not been established. The recent development of the Betula papyrifera (white birch) transcriptome has allowed the discovery of genes involved in plant adaptation to stress. The main objective of the present study was to identify novel genes associated with nickel resistance in B. papyrifera. Our results from next generation sequencing and RT-qPCR analyses show that genes involved in transport activities are upregulated in nickel-resistant genotypes compared with susceptible forms. Detailed analysis of gene expression and genome analysis shows for the first time the existence of a TonB-dependent receptor and TonB-like family protein in non-prokaryotes. In addition, we have found that these proteins are associated with nickel resistance in B. papyrifera. Our experiments suggest that the TonB-dependent receptor may be exclusive to the Betula genus, suggesting that Betula species may have acquired the gene via horizontal gene transfer from prokaryotes or fungi.

Effects of Elevated Atmospheric Carbon Dioxide and Tropospheric Ozone on Phytochemical Composition of Trembling Aspen ( Populus tremuloides ) and Paper Birch ( Betula papyrifera ).

Anthropogenic activities are altering levels of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3). These changes can alter phytochemistry, and in turn, influence ecosystem processes. We assessed the individual and combined effects of elevated CO2 and O3 on the phytochemical composition of two tree species common to early successional, northern temperate forests. Trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) were grown at the Aspen FACE (Free-Air Carbon dioxide and ozone Enrichment) facility under four combinations of ambient and elevated CO2 and O3. We measured, over three years (2006-08), the effects of CO2 and O3 on a suite of foliar traits known to influence forest functioning. Elevated CO2 had minimal effect on foliar nitrogen and carbohydrate levels in either tree species, and increased synthesis of condensed tannins and fiber in aspen, but not birch. Elevated O3 decreased nitrogen levels in both tree species and increased production of sugar, condensed tannins, fiber, and lignin in aspen, but not birch. The magnitude of responses to elevated CO2 and O3 varied seasonally for both tree species. When co-occurring, CO2 offset most of the changes in foliar chemistry expressed under elevated O3 alone. Our results suggest that levels of CO2 and O3 predicted for the mid-twenty-first century will alter the foliar chemistry of northern temperate forests with likely consequences for forest community and ecosystem dynamics.