De-methyl esterification of homogalacturonan and subsequent cross-linking with Ca (2+) is hypothesized to enhance the freezing survival of cold acclimated plants by reducing the porosity of primary cell walls. To test this theory, we collected leaf epidermal peels from non- (23/18 degrees C) and cold acclimated (2 weeks at 12/4 degrees C) Japanese bunching onion (Allium fistulosum L.). Cold acclimation enhances the temperature at which half the cells survived freezing injury by 8 degrees C (LT50 = -20 degrees C) and reduces tissue permeability by 70-fold as compared with non-acclimated epidermal cells. These effects were associated with greater activity of pectin methylesterase (PME) and a reduction in the methyl esterification of homogalacturonan. Non-acclimated plants treated with 50 mM CaCl2 accumulated higher concentrations of galacturonic acid, Ca (2+) in the cell wall and a lower number of visible cell wall pores compared to levels observed in cold acclimated plants. Using cryo-microscopy, we observed that a 50 mM CaCl2 treatment did not lower the LT50 of non-acclimated cells but reduced the lethal intracellular ice nucleation to temperatures observed in cold acclimated epidermal cells. We postulate the PME-homogalacturonan-mediated reduction in cell wall porosity is integral to intracellular freezing avoidance strategies in cold acclimated herbaceous cells.

The plant kingdom contains an enormous diversity of bioactive compounds which regulate plant growth and defends against biotic and abiotic stress. Some of these compounds, like flavonoids, have properties which are health supporting and relevant for industrial use. Many of these valuable compounds are synthesized in various pepper (Capsicum sp.) tissues. Further, a huge amount of biomass residual remains from pepper production after harvest, which provides an important opportunity to extract these metabolites and optimize the utilization of crops. Moreover, abiotic stresses induce the synthesis of such metabolites as a defense mechanism. Two different Capsicum species were therefore exposed to chilling temperature (24/18 ℃ vs. 18/12 ℃), to salinity (200 mM NaCl), or a combination thereof for 1, 7 and 14 days to investigate the effect of these stresses on the metabolome and transcriptome profiles of their leaves. Both profiles in both species responded to all stresses with an increase over time. All stresses resulted in repression of photosynthesis genes. Stress involving chilling temperature induced secondary metabolism whereas stresses involving salt repressed cell wall modification and solute transport. The metabolome analysis annotated putatively many health stimulating flavonoids (apigetrin, rutin, kaempferol, luteolin and quercetin) in the Capsicum biomass residuals, which were induced in response to salinity, chilling temperature or a combination thereof, and supported by related structural genes of the secondary metabolism in the network analysis.

The horticultural production of bell peppers generates large quantities of residual biomass. Abiotic stress stimulates the production of protective flavonoids, so the deliberate application of stress to the plants after fruit harvest could provide a strategy to valorize horticultural residuals by increasing flavonoid concentrations, facilitating their industrial extraction. Here we exposed two Capsicum cultivars, a chilli and a bell pepper, to cold and salt stress and combinations thereof to determine their valorization potential. Noninvasive image-based phenotyping and multiparametric fluorescence measurements indicated that all stress treatments inhibited plant growth and reduced the leaf chlorophyll fluorescence index, with the chilli cultivar showing greater sensitivity. The fluorescence-based FLAV index allowed the noninvasive assessment of foliar luteolin glycosides. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis showed that moderate cold increased the levels of two foliar antioxidant luteolin glycosides in both cultivars, with bell pepper containing the highest amounts (induced to maximum 5.5 mg g-1 DW cynaroside and 37.0 mg g-1 DW graveobioside A) after combined stress treatment. These data confirm the potential of abiotic stress for the valorization of residual leaf biomass to enhance the industrial extraction of antioxidant and bioactive flavonoids.

At the end of the annual horticultural production cycle of greenhouse-grown crops, large quantities of residual biomass are discarded. Here, we propose a new value chain to utilize horticultural leaf biomass for the extraction of secondary metabolites. To increase the secondary metabolite content of leaves, greenhouse-grown crop plants were exposed to low-cost abiotic stress treatments after the last fruit harvest. As proof of concept, we evaluated the production of the flavonoid rutin in tomato plants subjected to nitrogen deficiency. In an interdisciplinary approach, we observed the steady accumulation of rutin in young plants under nitrogen deficiency, tested the applicability of nitrogen deficiency in a commercial-like greenhouse, developed a high efficiency extraction for rutin, and evaluated the acceptance of the proposed value chain by its key actors economically. On the basis of the positive interdisciplinary evaluation, we identified opportunities and challenges for the successful establishment of horticultural leaf biomass as a novel source for secondary metabolites.

Fruits and vegetables are an important supplier of biological active substances, such as vitamins and secondary metabolites (SM) for human nutrition, but also for further industrial applications. Pepper (Capsicum annuum) is grown and consumed all over the world as a fresh vegetable or dried as a spice. It is also used as a coloring agent, as well for medical purposes. Pepper fruits are considered as an attractive source of health-related compounds, but other organs like the leaves and stem also contain considerable amounts of antioxidants, e.g., phenolic compounds. This indicates potential for valorization of residual biomass from horticultural production by using innovative bioeconomic concepts. Herein, we present an overview about the biosynthesis of phenolic compounds, with a special focus on flavonoids and their regulation in pepper, the current knowledge of amounts and distribution of these valuable substances, as well as possible strategies for: (1) increasing flavonoid contents in pepper, (2) improving the nutritional value of fruits, and (3) new concepts for utilization of residual biomass from horticultural production.

Plant cell walls participate in all plant-environment interactions. Maintaining cell wall integrity (CWI) during these interactions is essential. This realization led to increased interest in CWI and resulted in knowledge regarding early perception and signalling mechanisms active during CWI maintenance. By contrast, knowledge regarding processes mediating changes in cell wall metabolism upon CWI impairment is very limited. To identify genes involved and to investigate their contributions to the processes we selected 23 genes with altered expression in response to CWI impairment and characterized the impact of T-DNA insertions in these genes on cell wall composition using Fourier-Transform Infrared Spectroscopy (FTIR) in Arabidopsis thaliana seedlings. Insertions in 14 genes led to cell wall phenotypes detectable by FTIR. A detailed analysis of four genes found that their altered expression upon CWI impairment is dependent on THE1 activity, a key component of CWI maintenance. Phenotypic characterizations of insertion lines suggest that the four genes are required for particular aspects of CWI maintenance, cell wall composition or resistance to Plectosphaerella cucumerina infection in adult plants. Taken together, the results implicate the genes in responses to CWI impairment, cell wall metabolism and/or pathogen defence, thus identifying new molecular components and processes relevant for CWI maintenance.

Viele pflanzliche Sekundarmetabolite haben antioxidative oder andere bioaktive Eigenschaften, weshalb sie einerseits wichtige Bestandteile der menschlichen Ernahrung sind, andererseits aber auch als pharmazeutische Verbindungen oder als Substrat fur die chemische Synthese von bioaktiven Substanzen verwendet werden. Pflanzen induzieren die Produktion solcher nutzbaren Sekundarmetabolite wie z.B. Flavonoiden als Reaktion auf abiotischen Stress. Die Produktion von Gemuse und Fruchten in Gewachshausern hinterlasst grose Mengen an ungenutzter pflanzlicher Biomasse, welche eine potentielle Ressource fur die Gewinnung wertvoller Metabolite darstellt. Durch eine kaskadenartige Verwendung von Gartenbaukulturen zur Produktion von Fruchten und Gemuse mit einer anschliesenden Gewinnung hochwertiger Substanzen aus der verbleibenden Restbiomasse wurde ein erheblicher Mehrwert generiert. Das Projekt TaReCa bearbeitet die Entwicklung einer masgeschneiderten Kaskadenverwertung von Paprikapflanzen-Restbiomasse aus dem Gartenbau. Dabei soll der pflanzliche Sekundarmetabolismus durch spezifische abiotische Stressbedingungen nach der Fruchternte gezielt induziert werden, um die Konzentrationen der Zielmetaboliten zu steigern. Durch umweltfreundliche und wirtschaftliche Extraktionsprozesse und eine anschliesende Verwertung des verbleibenden Pflanzenmaterials in einer Bioraffinerie wird die Wertschopfungskette erweitert. Eine Analyse der Anwendungsgebiete sowie Untersuchungen zur Akzeptanz der induzierten Inhaltsstoffe, Prozesse und Technologien werden helfen, das Marktpotenzial der Restbiomasse fur die Nutzung in Kaskaden zu evaluieren. Die masgeschneiderte Nutzung von Gartenbaubiomasse durch Lebensmittelproduktion, Extraktion bioaktiver Sekundarmetabolite und Bioraffinerien kann wirtschaftlich relevante, biobasierte Produkte fur industrielle Anwendungen erzeugen und somit zur Entwicklung einer nachhaltigen, effizienten und integrierten Biookonomie beitragen, ohne mit der Lebensmittelproduktion zu konkurrieren.

Plant cell walls are complex and dynamic structures that play important roles in growth and development, as well as in response to stresses. Pectin is a major polysaccharide of cell walls rich in galacturonic acid (GalA). Homogalacturonan (HG) is considered the most abundant pectic polymer in plant cell walls and is partially methylesterified at the C6 atom of galacturonic acid. Its degree (and pattern) of methylation (DM) has been shown to affect biomechanical properties of the cell wall by making pectin susceptible for enzymatic de-polymerization and enabling gel formation. Pectin methylesterases (PMEs) catalyze the removal of methyl-groups from the HG backbone and their activity is modulated by a family of proteinaceous inhibitors known as pectin methylesterase inhibitors (PMEIs). As such, the interplay between PME and PMEI can be considered as a determinant of cell adhesion, cell wall porosity and elasticity, as well as a source of signaling molecules released upon cell wall stress. This review aims to highlight recent updates in our understanding of the PMEI gene family, their regulation and structure, interaction with PMEs, as well as their function in response to stress and during development.

Updates in nanopore technology have made it possible to obtain gigabases of sequence data. Prior to this, nanopore sequencing technology was mainly used to analyze microbial samples. Here, we describe the generation of a comprehensive nanopore sequencing data set with a median read length of 11,979 bp for a self-compatible accession of the wild tomato species Solanum pennellii We describe the assembly of its genome to a contig N50 of 2.5 MB. The assembly pipeline comprised initial read correction with Canu and assembly with SMARTdenovo. The resulting raw nanopore-based de novo genome is structurally highly similar to that of the reference S. pennellii LA716 accession but has a high error rate and was rich in homopolymer deletions. After polishing the assembly with Illumina reads, we obtained an error rate of <0.02% when assessed versus the same Illumina data. We obtained a gene completeness of 96.53%, slightly surpassing that of the reference S. pennellii Taken together, our data indicate that such long read sequencing data can be used to affordably sequence and assemble gigabase-sized plant genomes.

Recent updates in sequencing technology have made it possible to obtain Gigabases of sequence data from one single flowcell. Prior to this update, the nanopore sequencing technology was mainly used to analyze and assemble microbial samples 1-3 . Here, we describe the generation of a comprehensive nanopore sequencing dataset with a median fragment size of 11,979 bp for the wild tomato species Solanum pennellii featuring an estimated genome size of ca 1.0 to 1.1 Gbases. We describe its genome assembly to a contig N50 of 2.5 MB using a pipeline comprising a Canu 4 pre-processing and a subsequent assembly using SMARTdenovo. We show that the obtained nanopore based de novo genome reconstruction is structurally highly similar to that of the reference S. pennellii LA716 5 genome but has a high error rate caused mostly by deletions in homopolymers. After polishing the assembly with Illumina short read data we obtained an error rate of <0.02 % when assessed versus the same Illumina data. More importantly however we obtained a gene completeness of 96.53% which even slightly surpasses that of the reference S. pennellii genome 5 . Taken together our data indicate such long read sequencing data can be used to affordably sequence and assemble Gbase sized diploid plant genomes. Raw data is available at http://www.plabipd.de/portal/solanum-pennellii and has been deposited as PRJEB19787.

This work investigates the effect of thermal bending on the tensile strength of bamboo canes. Two different bending-radii as well as the inner, outer and neutral fibre of bent bamboo canes are mechanically tested with a hydraulic testing machine. The results show a loss of tensile strength of up to 54% compared to a non-bent bamboo cane. In a current research project (Technical Product Harvesting) the growth of bamboo is directly manipulated into certain bending angles, with the goal to avoid additional manufacturing steps and energy input required for the thermal bending. The results allow the prospect that due to superior tensile strength compared to thermal bending it is furthermore worth mechanically to manipulate the bamboo's growth next its positive effect on the CO2-footprint.

Technical product harvesting (TEPHA) is a newly developing interdisciplinary approach in which bio-based production is investigated from a technical and ecological perspective. Society's demand for ecologically produced and sustainably operable goods is a key driver for the substitution of conventional materials like metals or plastics through bio-based alternatives. Technical product harvesting of near net shape grown components describes the use of suitable biomass for the production of technical products through influencing the natural shape of plants during their growth period. The use of natural materials may show positive effects on the amount of non-renewable resource consumption. This also increases the product recyclability at the end of its life cycle. Furthermore, through the near net shape growth of biomass, production steps can be reduced. As a consequence such approaches may save energy and the needed resources like crude oil, coal or gas. The derived near net shape grown components are not only considered beneficial from an environmental point of view. They can also have mechanical advantages through an intrinsic topology optimization in contrast to common natural materials, which are influenced in their shape after harvesting. In order to prove these benefits a comprehensive, interdisciplinary scientific strategy is needed. Here, both mechanical investigations and life cycle assessment as a method of environmental evaluation are used.

The development of sustainable, and ecologically-sound building components from natural and renewable sources is a key element in the reduction of energy and resource consumption in the building sector. Especially with regard to embodied energy, locally sourced wood- or plant-based products are favorable to conventional alternatives, and are able to responds to society's increased demand for sustainably manufactured goods. Therefore, advancing and facilitating the product development of bio-based building components is a pivotal method to foster sustainability in the built environment. This paper introduces a novel approach to the systematic development and production of bio-based products in order to decrease resource and energy consumption and increase recyclability by letting bio-material grow directly into a near net shaped topology.

Society's demand for ecologically produced and sustainably operable goods is a key driver to substitute conventional substances such as metals or plastics. Most of today's eco-design approaches are limited to the selection of the right material and the industrial processing, to manufacture the desired design. The authors of this work are scientists from the areas of cell-biology, eco-toxicology, engineering-and industrial-design, and teamed up to use directed natural growth of bio-materials. The aim is to minimize conventional production steps and decrease the amount of resources needed for manufacturing. In the first step the team categorizes and analyzes potential plants. In addition, requirements for different sorts of products are defined. Matching parts of both databases are identified. The aim of this research is to give an overview of possible function-plant relations of near net shape grown materials. Single materials as well as composites are taken into account. Eco-investigations include the whole Life Cycle Assessment. Additionally mechanical properties, design restrictions and surface quality are examined as major issues for sustainable, safe and sound products.