Optimizing Miscanthus for the Sustainable Bioeconomy:From Genes to Products

In this Research Topic we report advances in fundamental and applied aspects of the perennial C4 bioenergy crop Miscanthus (Miscanthus spp.) and its role in mitigating climate change as part of the bioeconomy. Miscanthus is extremely well suited for bioenergy, biofuel and bioproduct production over a wide geographic area including Europe and North America as well as its native Asia. Miscanthus offers a unique perspective within plant science: the challenge is to domesticate this novel crop for diverse environments and uses while simultaneously developing sustainable value chains to displace fossil fuels and contribute to climate change mitigation. Contributions to this Research Topic were offered from leading Miscanthus researchers from different parts of the world. We accepted 16 articles from 95 authors, which have generated 21,161 views at March 26 2018. Nine of the articles are the output of the European FP7 OPTIMISC project and describe multiple experiments investigating a common set of Miscanthus genotypes in Europe and Asia. These papers are complemented by seven additional articles from global authors, providing a comprehensive analysis of the state of the art of Miscanthus research and application

Moisture content estimation and senescence phenotyping of novel Miscanthus hybrids combining UAV-based remote sensing and machine learning

Miscanthus is a leading perennial biomass crop that can produce high yields on marginal lands. Moisture content is a highly relevant biomass quality trait with multiple impacts on efficiencies of harvest, transport, and storage. The dynamics of moisture content during senescence and overwinter ripening are determined by genotype × environment interactions. In this paper, unmanned aerial vehicle (UAV)-based remote sensing was used for high-throughput plant phenotyping (HTPP) of the moisture content dynamics during autumn and winter senescence of 14 contrasting hybrid types (progeny of M. sinensis x M. sinensis [M. sin x M. sin, eight types] and M. sinensis x M. sacchariflorus [M. sin x M. sac, six types]). The time series of moisture content was estimated using machine learning (ML) models and a range of vegetation indices (VIs) derived from UAV-based remote sensing. The most important VIs for moisture content estimation were selected by the recursive feature elimination (RFE) algorithm and were BNDVI, GDVI, and PSRI. The ML model transferability was high only when the moisture content was above 30%. The best ML model accuracy was achieved by combining VIs and categorical variables (5.6% of RMSE). This model was used for phenotyping senescence dynamics and identifying the stay-green (SG) trait of Miscanthus hybrids using the generalized additive model (GAM). Combining ML and GAM modeling, applied to time series of moisture content values estimated from VIs derived from multiple UAV flights, proved to be a powerful tool for HTPP

Exploring the Treasure of Plant Molecules With Integrated Biorefineries

Despite significant progress toward the commercialization of biobased products, today’s biorefineries are far from achieving their intended goal of total biomass valorization and effective product diversification. The problem is conceptual. Modern biorefineries were built around well-optimized, cost-effective chemical synthesis routes, like those used in petroleum refineries for the synthesis of fuels, plastics, and solvents. However, these were designed for the conversion of fossil resources and are far from optimal for the processing of biomass, which has unique chemical characteristics. Accordingly, existing biomass commodities were never intended for modern biorefineries as they were bred to meet the needs of conventional agriculture. In this perspective paper, we propose a new path toward the design of efficient biorefineries, which capitalizes on a cross-disciplinary synergy between plant, physical, and catalysis science. In our view, the best opportunity to advance profitable and sustainable biorefineries requires the parallel development of novel feedstocks, conversion protocols and synthesis routes specifically tailored for total biomass valorization. Above all, we believe that plant biologists and process technologists can jointly explore the natural diversity of plants to synchronously develop both, biobased crops with designer chemistries and compatible conversion protocols that enable maximal biomass valorization with minimum input utilization. By building biorefineries from the bottom-up (i.e., starting with the crop), the envisioned partnership promises to develop cost-effective, biomass-dedicated routes which can be effectively scaled-up to deliver profitable and resource-use efficient biorefineries

Tissue tropism in parasitic diseases

© 2019 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.Parasitic diseases, such as sleeping sickness, Chagas disease and malaria, remain a major cause of morbidity and mortality worldwide, but particularly in tropical, developing countries. Controlling these diseases requires a better understanding of host-parasite interactions, including a deep appreciation of parasite distribution in the host. The preferred accumulation of parasites in some tissues of the host has been known for many years, but recent technical advances have allowed a more systematic analysis and quantifications of such tissue tropisms. The functional consequences of tissue tropism remain poorly studied, although it has been associated with important aspects of disease, including transmission enhancement, treatment failure, relapse and clinical outcome. Here, we discuss current knowledge of tissue tropism in Trypanosoma infections in mammals, describe potential mechanisms of tissue entry, comparatively discuss relevant findings from other parasitology fields where tissue tropism has been extensively investigated, and reflect on new questions raised by recent discoveries and their potential impact on clinical treatment and disease control strategies.L.M.F. is an Investigator of the Fundação para a Ciência e Tecnologia (IF/01050/2014) and the laboratory is funded by ERC (FatTryp, ref. 771714). M.D.N. is funded by Long Term EMBO Postdoctoral fellowship ALTF 1048-2016. Publication of this work was also funded by UID/BIM/50005/2019, from Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through Fundos do Orçamento de Estado.info:eu-repo/semantics/publishedVersio

Neochloris oleoabundans cell walls have an altered composition when cultivated under different growing conditions

The impact that environmental factors have on the intracellular components of microalgae has been the focus of research for a number of decades. Despite that, their effects on the cell wall have received very little attention. In this study, we investigated how different growing conditions affect the cell walls of N. oleoabundans. The results revealed that the cell wall composition varied in that the modifications were different in the four cultivation media: freshwater nitrogen-replete (optimum culture) and -depleted conditions, and seawater nitrogen-replete and -depleted conditions. Nitrogen deficiency in freshwater cultivation was the only condition that significantly (p <.05) increased the total content of carbohydrates in the cell wall. The three most abundant components of freshwater-cultivated cell wall polysaccharides were rhamnose, galactose and glucuronic acid whereas in seawater media the main components of cell wall polysaccharides were rhamnose, glucose and galactose. The combined results of the biochemical analyses and monoclonal antibodies epitope-binding revealed that N. oleoabundans cell walls are likely composed of sulphated polysaccharides enriched in mannose, β-(1 → 4)-D-mannans, and glucose as they grow in seawater. Salinity and nitrogen deficiency also had an impact on the nitrogenous components of the cell wall. Under these conditions we observed a decrease in glucosamine in the cell wall. The analysis of specific binding of monoclonal antibodies, revealed that the cell wall of N. oleoabundans is possibly enriched in arabinogalactan proteins (AGPs). Under salinity and nitrogen deficiency N. oleoabundans increased the proportion of the non-polar to polar amino acids in the cell walls. An increase of leucine in the cell walls may suggest that N. oleoabundans contains leucine-rich repeat proteins which are known to play a vital role in stress responses. This report provides new insights into microalgae cell wall biology and how cell walls are remodelled when growing under different conditions.</p

Trypanosoma brucei triggers a broad immune response in the adipose tissue

Copyright: © 2021 Machado et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Adipose tissue is one of the major reservoirs of Trypanosoma brucei parasites, the causative agent of sleeping sickness, a fatal disease in humans. In mice, the gonadal adipose tissue (AT) typically harbors 2-5 million parasites, while most solid organs show 10 to 100-fold fewer parasites. In this study, we tested whether the AT environment responds immunologically to the presence of the parasite. Transcriptome analysis of T. brucei infected adipose tissue revealed that most upregulated host genes are involved in inflammation and immune cell functions. Histochemistry and flow cytometry confirmed an increasingly higher number of infiltrated macrophages, neutrophils and CD4+ and CD8+ T lymphocytes upon infection. A large proportion of these lymphocytes effectively produce the type 1 effector cytokines, IFN-γ and TNF-α. Additionally, the adipose tissue showed accumulation of antigen-specific IgM and IgG antibodies as infection progressed. Mice lacking T and/or B cells (Rag2-/-, Jht-/-), or the signature cytokine (Ifng-/-) displayed a higher parasite load both in circulation and in the AT, demonstrating the key role of the adaptive immune system in both compartments. Interestingly, infections of C3-/- mice showed that while complement system is dispensable to control parasite load in the blood, it is necessary in the AT and other solid tissues. We conclude that T. brucei infection triggers a broad and robust immune response in the AT, which requires the complement system to locally reduce parasite burden.This work was supported by the European Research Council (FatTryp, ref. 771714) awarded to LMF, by Fundação para a Ciência e Tecnologia (CEECIND/03322/2018) awarded to LMF, (PTDC/MED-IMU/30948/2017 and CEECIND/00697/2018) awarded to KS, (PD/BD/128286/2017) awarded to HM, (SFRH/BPD/89833/2012) awarded to ST, (IMM/BI/83-2017 through PTDC/BIM-MET/4471/2014) awarded to TB-R and by the National Institutes of Health (NIGMS K99GM132557) awarded to FR-F. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

Convergent evolution of hetero‐oligomeric cellulose synthesis complexes in mosses and seed plants

In seed plants, cellulose is synthesized by rosette‐shaped cellulose synthesis complexes (CSCs) that are obligate hetero‐oligomeric, comprising three non‐interchangeable cellulose synthase (CESA) isoforms. The moss Physcomitrella patens has rosette CSCs and seven CESAs, but its common ancestor with seed plants had rosette CSCs and a single CESA gene. Therefore, if P. patens CSCs are hetero‐oligomeric, then CSCs of this type evolved convergently in mosses and seed plants. Previous gene knockout and promoter swap experiments showed that PpCESAs from class A (PpCESA3 and PpCESA8) and class B (PpCESA6 and PpCESA7) have non‐redundant functions in secondary cell wall cellulose deposition in leaf midribs, whereas the two members of each class are redundant. Based on these observations, we proposed the hypothesis that the secondary class A and class B PpCESAs associate to form hetero‐oligomeric CSCs. Here we show that transcription of secondary class A PpCESAs is reduced when secondary class B PpCESAs are knocked out and vice versa, as expected for genes encoding isoforms that occupy distinct positions within the same CSC. The class A and class B isoforms co‐accumulate in developing gametophores and co‐immunoprecipitate, suggesting that they interact to form a complex in planta. Finally, secondary PpCESAs interact with each other, whereas three of four fail to self‐interact when expressed in two different heterologous systems. These results are consistent with the hypothesis that obligate hetero‐oligomeric CSCs evolved independently in mosses and seed plants and we propose the constructive neutral evolution hypothesis as a plausible explanation for convergent evolution of hetero‐oligomeric CSCs

Site-specific management of miscanthus genotypes for combustion and anaerobic digestion:A comparison of energy yields

In Europe, the perennial C4 grass miscanthus is currently mainly cultivated for energy generation via combustion. In recent years, anaerobic digestion has been identified as a promising alternative utilization pathway. Anaerobic digestion produces a higher-value intermediate (biogas), which can be upgraded to biomethane, stored in the existing natural gas infrastructure and further utilized as a transport fuel or in combined heat and power plants. However, the upgrading of the solid biomass into gaseous fuel leads to conversion-related energy losses, the level of which depends on the cultivation parameters genotype, location, and harvest date. Thus, site-specific crop management needs to be adapted to the intended utilization pathway. The objectives of this paper are to quantify (i) the impact of genotype, location and harvest date on energy yields of anaerobic digestion and combustion and (ii) the conversion losses of upgrading solid biomass into biogas. For this purpose, five miscanthus genotypes (OPM 3, 6, 9, 11, 14), three cultivation locations (Adana, Moscow, Stuttgart), and up to six harvest dates (August-March) were assessed. Anaerobic digestion yielded, on average, 35% less energy than combustion. Genotype, location, and harvest date all had significant impacts on the energy yield. For both, this is determined by dry matter yield and ash content and additionally by substrate-specific methane yield for anaerobic digestion and moisture content for combustion. Averaged over all locations and genotypes, an early harvest in August led to 25%and a late harvest to 45%conversion losses. However, each utilization option has its own optimal harvest date, determined by biomass yield, biomass quality, and cutting tolerance. By applying an autumn green harvest for anaerobic digestion and a delayed harvest for combustion, the conversion-related energy loss was reduced to an average of 18%. This clearly shows that the delayed harvest required tomaintain biomass quality for combustion is accompanied by high energy losses through yield reduction over winter. The pre-winter harvest applied in the biogas utilization pathway avoids these yield losses and largely compensates for the conversion-related energy losses of anaerobic digestion