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The aim of the present study was to elucidate the role of oxidative stress in the mode of action of acetolactate synthase (ALS) inhibiting herbicides. Two populations of Amaranthus palmeri S. Watson from Spain (sensitive and resistant to nicosulfuron, due to mutated ALS) were grown hydroponically and treated with different rates of the ALS inhibitor nicosulfuron (one time and three times the field recommended rate). Seven days later, various oxidative stress markers were measured in the leaves: H2O2, MDA, ascorbate and glutathione contents, antioxidant enzyme activities and gene expression levels. Under control conditions, most of the analysed parameters were very similar between sensitive and resistant plants, meaning that resistance is not accompanied by a different basal oxidative metabolism. Nicosulfuron-treated sensitive plants died after a few weeks, while the resistant ones survived, independently of the rate. Seven days after herbicide application, the sensitive plants that had received the highest nicosulfuron rate showed an increase in H2O2 content, lipid peroxidation and antioxidant enzymatic activities, while resistant plants did not show these responses, meaning that oxidative stress is linked to ALS inhibition. A supralethal nicosulfuron rate was needed to induce a significant oxidative stress response in the sensitive population, providing evidence that the lethality elicited by ALS inhibitors is not entirely dependent on oxidative stress. This work was financed by the Public University of Navarre (Project UPNA20-6138) and the Spanish Ministry of Science and Innovation (2020 117723-RB-100). ME is the holder of a predoctoral fellowship of the Basque Government and he also received a mobility grant from the same Government. The authors would like to acknowledge G. Garijo, J. Encinas and C. Jiménez for technical assistance, and J. Torra (University of Lleida, CAT, Spain) for providing seeds.

Additional file 2. Ecosystem services categorization.

Additional file 3. Soil ecosystem services.

Table S1. Sequence information on forward and reverse primers used to determine gene expression levels via quantitative real-time PCR. Table S2. Quantitative real-time PCR parameters according to the MIQE guidelines. (DOCX 32 kb)

Additional file 1. Additional table and figure.

Lipid peroxidation in leaves and roots of A. thaliana wild-type and spl7 knockout plants. Nineteen-days-old plants were exposed for 24 h to 2 μM CuSO4, 5 μM CdSO4 or grown under control conditions. Data are mean ± S.E. of 4 biological replicates. Significant treatment differences (P

Forward and reverse primers used to determine gene expression levels via quantitative real-time PCR. E-E-jn, exon-exon junction; E-I-b, exon-intron boundary; YLS, yellow-leaf-specific; UBQ10, ubiquitin; ACT, actin ; EF, elongation factor; APS, ATP sulfurylase; SULTR, sulfate transporter; LAC, laccase; CSD, Cu/Zn superoxide dismutase; FSD, Fe superoxide dismutase. *Pri-miRNA primer concentrations were increased to 900 nM. (DOCX 18 kb)

Verification of the T-DNA insertion in the spl7 mutant. Primers were designed using T-DNA primer design. (DOCX 32 kb)

Quantitative real-time PCR parameters according to the Minimum Information for publication of Quantitative real-time PCR Experiments (MIQE) guidelines derived from Bustin et al. [51]. (DOCX 16 kb)

Cadmium (Cd) and zinc (Zn) were applied to durum wheat seedlings on hydroponics in concentrations of 50 μM and 600 μM respectively, causing about 50% relative growth inhibition (RGI) at the end of a 10-day-exposure period. Both metals provoked visual toxicity symptoms such as root browning and leaf chlorosis in Cd-exposed seedlings and root colour lightening and leaf necrotic spots in Zn-exposed seedlings. On a biochemical level, the apparent phytotoxicity was accompanied by oxidative stress-related responses such as increased lipid peroxidation and electrolyte leakage as well as increased activities of superoxide dismutase and catalase.

Background: Maternal smoking during pregnancy results in an increased risk of low birth weight through perturbations in the utero-placental exchange. Epigenetics and mitochondrial function in fetal tissues might be molecular signatures responsive to in utero tobacco smoke exposure. Methods: In the framework of the ENVIRONAGE birth cohort, we investigated the effect of self-reported tobacco smoke exposure during pregnancy on birth weight and the relation with placental tissue markers such as, (1) relative mitochondrial DNA (mtDNA) content as determined by real-time quantitative PCR, (2) DNA methylation of specific loci of mtDNA (D-loop and MT-RNR1), and (3) DNA methylation of the biotransformation gene CYP1A1 (the last two determined by bisulfite-pyrosequencing). The total pregnant mother sample included 255 non-smokers, 65 former-smokers who had quit smoking before pregnancy, and 62 smokers who continued smoking during pregnancy. Results: Smokers delivered newborns with a birth weight on average 208 g lower [95% confidence interval (CI) −318 to −99, p = 0.0002] than mothers who did not smoke during pregnancy. In the smoker group, the relative mtDNA content was lower (−21.6%, 95% CI −35.4 to −4.9%, p = 0.01) than in the non-smoker group; whereas, absolute mtDNA methylation levels of MT-RNR1 were higher (+0.62%, 95% CI 0.21 to 1.02%, p = 0.003). Lower CpG-specific methylation of CYP1A1 in placental tissue (−4.57%, 95% CI −7.15 to −1.98%, p

Green roofs contribute to more sustainable cities, but current commercial substrates suffer from important limitations. If carefully selected, biochar could serve as a viable option for a more sustainable green roof substrate. We propose a protocol to select an optimal biochar for green roof substrate amendment. Coffee husks, medium‑density fiberboard, palm date fronds, and a mixture of waste wood, tree bark, and olive stone kernels are selected as residues for biochar production to develop a selection protocol. The residues are pyrolyzed at 350, 450, 500, and 550 ◦C in a lab‑scale reactor. A pyrolysis temperature of 450 ◦C is selected for upscaling and is based on biochar yield, pH, salinity, and elemental composition. From evaluating the biochar characteristics after upscaling, it can be concluded that the biochar’s carbonization degree is mainly controlled by pyrolysis temper‑ ature, while yield, pH, and salinity are more dependent on the biomass properties. Ultimately, our procedure evaluates the presence of important contaminants, the biochar’s water holding capacity, salinity, pH, and carbonization degree. To validate the developed protocol, plant coverage exper‑ iments on green roofs are performed, which are quantified using a novel digital image processing method, demonstrating its efficient use to facilitate future biochar selection in substrates. This work was supported by Vlaams Agentschap Innoveren en Ondernemen (VLAIO) and European Institute of Innovation and Technology (EIT) [BM20160604]. Institutional

Two different heat treatments for MDF, microwave assisted pyrolysis (MWP) and conventional pyrolysis (CPS), are investigated. The influence of different microwave absorbers (activated carbon (AC) and K2CO3) and different microwave powers in MWP and different temperatures in CPS on the characteristics of biochar is reviewed. Morphology and chemical properties of the obtained biochars are evaluated comparing biochar yield, ultimate analysis, proximate analysis, biochar stability test, FTIR spectroscopy and solid-state 13C CP/MAS NMR spectroscopy. The resulting biochars of both processes are compared to find the best production method. An increasing microwave power without the use of MWA, leads to a higher degree of aromaticity. The addition of increasing amounts of AC at low microwave power (300 W) leads to higher pyrolysis temperatures and more aromatic biochars. At 400 W a more aromatic biochar with a more open surface is achieved compared to 300 W. However, the addition of an increasing amount of AC as a MWA at 400 W induces a lower pyrolysis temperature with increasing biochar yields and decreasing aromaticity. K2CO3 is more effective as a MWA and produces more aromatic biochar at lower microwave power than when using AC. In general MWP yields a biochar with a higher degree of aromaticity at lower temperatures than CPS. Both CPS and MWP are viable options for transforming MDF into a value added biochar. This work was supported byAgentschap Innoveren en Ondernemen (VLAIO) [BM20160604]; European Institute of Technology (EIT); and Research Foundation Flanders (postdoctoral fellowship D. Vandamme [FWO - 12D8914N]). Koen Van Vinckenroye for support with the 13C solid state NMR measurements Elsy Thijssen and Martine Vanhamel for FTIR measurements This work was supported byAgentschap Innoveren en Ondernemen (VLAIO) [BM20160604]; European Institute of Technology (EIT); and Research Foundation Flanders (postdoctoral fellowship D. Vandamme [FWO – 12D8914N]).

Biochar has emerged as a filler material for bio-degradable composites with favorable thermal and mechanical properties. Therefore, biochar is used in poly (lactic acid) (PLA) and PLA/thermoplastic starch (TPS) based composites. The crystallization and thermo-analytical properties of these blends with increasing amounts (20 to 50 wt. %) of biochar are investigated. In thermogravimetric analysis, the PLA/char composites’ onset degradation temperature and temperature of maximum weight loss decrease with increasing biochar concentrations (320 °C to 275 °C and 380 °C to 350 °C respectively). Contrastingly, in the PLA/TPS/char composites, the impact of the biochar is shielded by the TPS. The unaltered glass transition demonstrates that biochar does not act as a plasticizer in any of the composites, while TPS does. Biochar acts as a nucleation agent, but hinders further crystal growth at high concentrations, as confirmed by isothermal crystallization and infrared spectroscopy. The TPS smoothens the PLA/biochar interface, leading to an obstructed nucleation effect of biochar, proven by differential scanning calorimetry, infrared spectroscopy and scanning electron microscopy. This work demonstrates the shielding effect TPS has on biochar and can help to further understand and optimize the production and biodegradability of these composites. This work was supported by Vlaams Agentschap Innoveren en Ondernemen (VLAIO) and European Institute of Innovation and Technology (EIT) [BM20160604].

Proteotoxic stress, or the accumulation of unfolded or misfolded proteins, occurs in response to a multitude of (a)biotic stresses and in multiple subcellular compartments, including the ER, chloroplasts, and mitochondria. The unfolded protein response or UPR is an evolutionary conserved mechanism in eukaryotes to cope with ER stress. In plants, the basic machinery for this response has been elucidated recently, but the molecular players involved in UPR, originating in other organelles, deserve scrutiny. Reactive oxygen species (ROS), ethylene (ETH), and sugars, are crucial players in stress responses. Upon proteotoxic stress, they act both up- and downstream of UPR. Upon stress, a trade-off between plant growth and defense responses defines the capacity for survival. Stress can result in accumulation of misfolded proteins in the endoplasmic reticulum (ER) and other organelles. To cope with these proteotoxic effects, plants rely on the unfolded protein response (UPR). The involvement of reactive oxygen species (ROS), ethylene (ETH), and sugars, as well as their crosstalk, in general stress responses is well established, yet their role in UPR deserves further scrutiny. Here, a synopsis of current evidence for ROS–ETH–sugar crosstalk in UPR is discussed. We propose that this triad acts as a major signaling hub at the crossroads of survival and death, integrating information from ER, chloroplasts, and mitochondria, thereby facilitating a coordinated stress response.

The commonly used Arabidopsis thaliana natural accessions Columbia (Col-0) and Wassilewskija (Ws) are known to differ in their metal sensitivity, with Col-0 being more sensitive to copper (Cu) and cadmium (Cd) than Ws. As both Cu and Cd are known to affect Cu homeostasis, it was investigated whether this process is part of an accession-specific mechanism underlying their difference in metal sensitivity. As roots are the first contact point during metal exposure, responses were compared between roots of both accessions of hydroponically grown plants exposed to excess Cu or Cd for 24 and 72 h.Root Cu levels increased in both accessions under Cu and Cd exposure. However, under Cu exposure, the downregulation of Cu transporter (COPT) genes in combination with a more pronounced upregulation of metallothionein gene MT2b indicated that Ws plants coped better with the elevated Cu concentrations. The Cdinduced disturbance in Cu homeostasis was more efficiently counteracted in roots of Ws plants than in Col0 plants. This was indicated by a higher upregulation of the SPL7-mediated pathway, crucial in the regulation of the Cu homeostasis response.In conclusion, maintaining the Cu homeostasis response in roots is key to accession-specific differences in Cu and Cd sensitivity. This work was supported by BOF funding from Hasselt University through a PhD grant for Rafaela Amaral dos Reis [grant number BOF12NI28]. Additional funding came from FWO projects [grant numbers G0C7518 N, G0B6716 N].

When terrestrial environments get contaminated with long-lived gamma emitting radionuclides, plants that grow in these contaminated areas are exposed to gamma radiation during consecutive generations. Therefore it is important to evaluate the gamma induced stress response in plants in and between generations. The objective of this research is to reveal differences at the level of the antioxidative stress response between generations with a different radiation history. An experiment was conducted in which 7-days old Arabidopsis thaliana plants were exposed for 14 days to four different gamma dose rates: 22 mGy/h, 38 mGy/h, 86 mGy/h and 457 mGy/h. Two different plant groups were used: plants that were not exposed to gamma radiation before (P0) and plants that received the aforementioned gamma treatment during their previous generation (S1). Growth, the concentration of the antioxidants ascorbate and glutathione, a number of antioxidative enzyme activities and their gene transcript levels were analysed. A dose-rate dependent induction was seen for catalase (CAT) and guaiacol peroxidase (GPX) in the roots and for syringaldazine peroxidase (SPX) in the shoots. Differences between the two generations were observed for CAT and GPX in the roots, where a significantly higher activity of these reactive oxygen species (ROS) detoxifying enzymes was observed in the S1 generation. For SPX in the shoots, a dose dependent upregulation was observed in the PO generation. However, high SPX activities were present for all doses in the S1 generation. These differences in enzyme activity between generations for SPX and GPX and the involvement of these enzymes in cell wall biosynthesis, suggest an important role for cell wall strengthening in the response to gamma irradiation. (C) 2016 Elsevier Ltd. All rights reserved. This project was supported by the European project COMET (7th PCRD EURATOM Contract Number: Fission-2012-3.4.1-604794) (www.comet-radioecology.org) and the Belgian nuclear research centre (SCK CEN).

The reactive oxygen species (ROS)-signaling pathway is very important in heavy metal toxicity. Induction of the antioxidative defense mechanism, comprising ROS-scavenging enzymes and metabolites, in plants after environmental uranium contamination has been insufficiently studied in the past. This study aimed to analyze oxidative stress related responses in Arabidopsis thaliana after uranium exposure. Seventeen-day-old seedlings were exposed to 0, 0.1, 1, 10 and 100 μM uranium for 3 days. After exposure to 100 μM uranium, a decrease in fresh weight for leaves and roots was observed, leaves colored anthocyanous and roots were stunted and yellow. To reveal the importance of oxidative stress in uranium toxicity, alterations in ROS-scavenging enzymes were studied at protein and transcriptional level. Superoxide dismutase (SOD) capacities increased in leaves and roots after exposure to 100 μM uranium but no differences were observed for catalase (CAT) capacities. Transcript levels of different SODs located at various cellular compartments were affected depending on the place of action. Gene expression of CAT in leaves and roots was also affected after uranium exposure. Results indicate that oxidative stress plays an important role in uranium toxicity but suggest that plant responses differ for leaves and roots.