Salt stress alters the cell wall components and structure in Miscanthus sinensis stems.

Miscanthus is a perennial grass suitable for the production of lignocellulosic biomass on marginal lands. The effects of salt stress on Miscanthus cell wall composition and its consequences on biomass quality have nonetheless received relatively little attention. In this study, we investigated how exposure to moderate (100 mM NaCl) or severe (200 mM NaCl) saline growing conditions altered the composition of both primary and secondary cell wall components in the stems of 15 Miscanthus sinensis genotypes. The exposure to stress drastically impacted biomass yield and cell wall composition in terms of content and structural features. In general, the observed compositional changes were more pronounced under severe stress conditions and were more apparent in genotypes with a higher sensitivity towards stress. Besides a severely reduced cellulose content, salt stress led to increased pectin content, presumably in the form of highly branched rhamnogalacturonan type I. Although salt stress had a limited effect on the total lignin content, the acid-soluble lignin content was strongly increased in the most sensitive genotypes. This effect was also reflected in substantially altered lignin structures and led to a markedly reduced incorporation of syringyl subunits and p-coumaric acid moieties. Interestingly, plants that were allowed a recovery period after stress ultimately had a reduced lignin content compared to those continuously grown under control conditions. In addition, the salt stress-induced cell wall alterations contributed to an improved enzymatic saccharification efficiency.

Assessment of the radionuclide remediation potential of novel miscanthus hybrids.

There are few studies related to the radionuclide remediation options, which comply to the demands of the environmentally non-destructive physical remediation methods. So far, most of the research was conducted on the phytoremediation capacity of different energy crops, as well as the established miscanthus hybrids which involved metal and heavy metal contaminants. Hence, the objective of this research was the radioecological characterization of the examined agroecosystem, including the initial source of the radionuclides (soil) as well as different miscanthus hybrids grown on the same soil. The results have shown that the radioactive content of soil was similar to the global averages. All measurements of the activity concentration of 137Cs in miscanthus samples were below the detection limits. There is also an indication that 210Pb is leaching into the lower layers (or is being taken up by miscanthus plant from the upper layers). Moreover, transfer factors (TFs) for radionuclides, as a more precise parameter for evaluating the phytoremediation potential, were calculated; the TFs were found to be very low for 226Ra (≤0.07), TFs for 40K (≤0.39) and for 232Th (≤0.21) were in the lower limits, whereas the TFs for 238U were found to be the highest (≤0.92). For 210Pb, the TFs were not calculated, since the expectation was that a significant part of the measured quantity came from the air, and not through the soil. Having in mind the sustainability and the circularity aspect of the radionuclide phytoremediation system, the appropriate management method should be applied for the disposal and utilization of the biomass contaminated with radionuclides. This research has shown that the radiological content in miscanthus is high enough and the ash content is low enough that miscanthus ash could be considered as a NORM (Naturally Occurring Radioactive Material), and it can be further used for the construction industry (i.e. concrete, tiles), in mixtures with other materials with certain limitations, similar to the utilization of ash from other sources such as coal or wood.

Cell wall as a barrier for protein extraction from tomato leaves: A biochemical study.

Solanum lycopersicum (Tomato) leaves and stems are considered waste. Valorization of this waste can be achieved by for example the extraction of proteins. This prospect is promising but currently not feasible, since protein extraction yields from tomato leaves are low, amongst other due to the (physical) barrier formed by the plant cell walls. However, the molecular aspects of the relationship between cell wall properties and protein extractability from tomato leaves are currently not clear and thus objective of this study. To fill this knowledge gap the biochemical composition of plant cell walls was measured and related to protein extraction yields at different plant ages, leaf positions, and across different tomato accessions, including two Solanum lycopersicum cultivars and the wildtype species S. pimpinellifolium and S. pennellii. For all genotypes, protein extraction yields from tomato leaves were the highest in young tissues, with a decreasing trend towards older plant material. This decrease of protein extraction yield was accompanied by a significant increase of arabinose and galacturonic acid content and a decrease of galactose content in the cell walls of old-vs-young tissues. This resulted in strong negative correlations between protein extraction yield and the content of arabinose and galacturonic acid in the cell wall, and a positive correlation between the content of galactose and protein extraction yield. Overall, these results point to the importance of the pectin network on protein extractability, making pectin a potential breeding target for enhancing protein extractability from tomato leaves.

Assessment of Drought and Zinc Stress Tolerance of Novel Miscanthus Hybrids and Arundo donax Clones Using Physiological, Biochemical, and Morphological Traits.

High-yield potential perennial crops, such as Miscanthus spp. and Arundo donax are amongst the most promising sources of sustainable biomass for bioproducts and bioenergy. Although several studies assessed the agronomic performance of these species on diverse marginal lands, research to date on drought and zinc (Zn) resistance is scarce. Thus, the objective of this study was to investigate the drought and Zn stress tolerance of seven novel Miscanthus hybrids and seven Arundo clones originating from different parts of Italy. We subjected both species to severe drought (less than 30%), and Zn stress (400 mg/kg-1 of ZnSO4) separately, after one month of growth. All plants were harvested after 28 days of stress, and the relative drought and Zn stress tolerance were determined by using a set of morpho-physio-biochemical and biomass attributes in relation to stress tolerance indices (STI). Principal component analysis (PCA), hierarchical clustering analysis (HCA) and stress tolerance indices (STI) were performed for each morpho-physio-biochemical and biomass parameters and showed significant relative differences among the seven genotypes of both crops. Heatmaps of these indices showed how the different genotypes clustered into four groups. Considering PCA ranking value, Miscanthus hybrid GRC10 (8.11) and Arundo clone PC1 (11.34) had the highest-ranking value under both stresses indicating these hybrids and clones are the most tolerant to drought and Zn stress. In contrast, hybrid GRC3 (-3.33 lowest ranking value) and clone CT2 (-5.84) were found to be the most sensitive to both drought and Zn stress.

The challenge of breeding for reduced off-flavor in faba bean ingredients.

The growing interest in plant protein sources, such as pulses, is driven by the necessity for sustainable food production and climate change mitigation strategies. Faba bean (Vicia faba L.) is a promising protein crop for temperate climates, owing to its remarkable yield potential (up to 8 tonnes ha-1 in favourable growing conditions) and high protein content (~29% dry matter basis). Nevertheless, the adoption of faba bean protein in plant-based products that aim to resemble animal-derived counterparts is hindered by its distinctive taste and aroma, regarded as "off-flavors". In this review, we propose to introduce off-flavor as a trait in breeding programs by identifying molecules involved in sensory perception and defining key breeding targets. We discuss the role of lipid oxidation in producing volatile and non-volatile compounds responsible for the beany aroma and bitter taste, respectively. We further investigate the contribution of saponin, tannin, and other polyphenols to bitterness and astringency. To develop faba bean varieties with diminished off-flavors, we suggest targeting genes to reduce lipid oxidation, such as lipoxygenases (lox) and fatty acid desaturases (fad), and genes involved in phenylpropanoid and saponin biosynthesis, such as zero-tannin (zt), chalcone isomerase (chi), chalcone synthase (chs), ß-amyrin (bas1). Additionally, we address potential challenges, including the need for high-throughput phenotyping and possible limitations that could arise during the genetic improvement process. The breeding approach can facilitate the use of faba bean protein in plant-based food such as meat and dairy analogues more extensively, fostering a transition toward more sustainable and climate-resilient diets.

Highly differentiated genomic properties underpin the different cell walls of Poaceae and eudicots.

Plant cell walls of Poaceae and eudicots differ substantially, both in the content and composition of their components. However, the genomic and genetic basis underlying these differences is not fully resolved. In this research, we analyzed multiple genomic properties of 150 cell wall gene families across 169 angiosperm genomes. The properties analyzed include gene presence/absence, copy number, synteny, occurrence of tandem gene clusters, and phylogenetic gene diversity. Results revealed a profound genomic differentiation of cell wall genes between Poaceae and eudicots, often associated with the cell wall diversity between these plant groups. For example, overall patterns of gene copy number variation and synteny were clearly divergent between Poaceae and eudicot species. Moreover, differential Poaceae-eudicot copy number and genomic contexts were observed for all the genes within the BEL1-like HOMEODOMAIN 6 regulatory pathway, which respectively induces and represses secondary cell wall synthesis in Poaceae and eudicots. Similarly, divergent synteny, copy number, and phylogenetic gene diversification were observed for the major biosynthetic genes of xyloglucans, mannans, and xylans, potentially contributing to the differences in content and types of hemicellulosic polysaccharides differences in Poaceae and eudicot cell walls. Additionally, the Poaceae-specific tandem clusters and/or higher copy number of PHENYLALANINE AMMONIA-LYASE, CAFFEIC ACID O-METHYLTRANSFERASE, or PEROXIDASE genes may underly the higher content and larger variety of phenylpropanoid compounds observed in Poaceae cell walls. All these patterns are discussed in detail in this study, along with their evolutionary and biological relevance for cell wall (genomic) diversification between Poaceae and eudicots.

Syntenic Cell Wall QTLs as Versatile Breeding Tools: Intraspecific Allelic Variability and Predictability of Biomass Quality Loci in Target Plant Species.

Syntenic cell wall QTLs (SQTLs) can identify genetic determinants of biomass traits in understudied species based on results from model crops. However, their effective use in plant breeding requires SQTLs to display intraspecific allelic variability and to predict causative loci in other populations/species than the ones used for SQTLs identification. In this study, genome assemblies from different accessions of Arabidopsis, rapeseed, tomato, rice, Brachypodium and maize were used to evaluate the intraspecific variability of SQTLs. In parallel, a genome-wide association study (GWAS) on cell wall quality traits was performed in miscanthus to verify the colocalization between GWAS loci and miscanthus SQTLs. Finally, an analogous approach was applied on a set of switchgrass cell wall QTLs retrieved from the literature. These analyses revealed large SQTLs intraspecific genetic variability, ranging from presence-absence gene variation to SNPs/INDELs and changes in coded proteins. Cell wall genes displaying gene dosage regulation, such as PAL and CAD, displayed presence-absence variation in Brachypodium and rapeseed, while protein INDELs were detected for the Brachypodium homologs of the rice brittle culm-like 8 locus, which may likely impact cell wall quality. Furthermore, SQTLs significantly colocalized with the miscanthus and switchgrass QTLs, with relevant cell wall genes being retained in colocalizing regions. Overall, SQTLs are useful tools to screen germplasm for relevant genes and alleles to improve biomass quality and can increase the efficiency of plant breeding in understudied biomass crops.

Bifidobacterium longum subsp. longum 51A Attenuates Signs of Inflammation in a Murine Model of Food Allergy.

Food allergy is a pathological condition that can lead to hives, swelling, gastrointestinal distress, cardiovascular and respiratory compromise, and even anaphylaxis. The lack of treatment resources emphasizes the necessity for new therapeutic strategies, and in this way, probiotics has been pointed out as an alternative, especially because of its immunomodulatory properties. The goal of this study was to evaluate the probiotic effect of Bifidobacterium longum subsp. longum 51A (BL51A) in a murine model of ovalbumin (OVA) food allergy, as well as to investigate the effect of the dose and viability of the bacteria on the proposed model. For this purpose, the probiotic effect was assessed by clinical, immunological, and histological parameters in mice treated or not with the BL51A and sensitized or not with OVA. Oral administration of BL51A prevented weight loss and reduced serum levels of IgE anti-OVA and of sIgA in the intestinal fluid. Also, it reduced the intestinal permeability, proximal jejunum damage, recruitment of eosinophils and neutrophils, and levels of eotaxin-1, CXCL1/KC, IL4, IL5, IL6, IL13, and TNF. Furthermore, the treatment was able to increase the levels of IL10. Investigating different doses administered, the level of 108 CFU showed the best results in terms of protective effect. In addition, the administration of the inactivated bacteria did not present any beneficial effect. Results demonstrate that BL51A promotes a systemic immunomodulatory protective effect in a murine model of food allergy that depends on the dose and viability of the bacteria, suggesting its use as probiotic in such disease.

The role of plant age and leaf position on protein extraction and phenolic compounds removal from tomato (Solanum lycopersicum) leaves using food-grade solvents.

The large availability and considerable amount of proteins (approx. 30 % on dry matter) make tomato leaves attractive as a potential new protein source. In this study, the feasibility of extracting proteins and removing phenolic compounds from tomato leaves using food-grade solvents as function of plant age and leaf position was investigated. Water and 50-50 % ethanol-water were used. We found that most proteins (>70 mg/g leaf protein) remained in the pellet after extraction. The protein purity of the dry matter present in the supernatant did not exceed the original leaf protein content. Additionally, leaf position had stronger effect than plant age on the leaf protein content and extraction yield. Ethanol-water was more efficient in removing phenolic compounds than water. The most phenolic compounds was removed from the top leaves. For future processing, the diversity of leaves has to be considered when striving for full utilization of tomato plants (fruits and leaves).

Perennial biomass cropping and use: Shaping the policy ecosystem in European countries.

Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023-27) objectives provided they are carefully integrated into farming systems and landscapes. Despite significant research and development (R&D) investment over decades in herbaceous and coppiced woody PBCs, deployment has largely stagnated due to social, economic and policy uncertainties. This paper identifies the challenges in creating policies that are acceptable to all actors. Development will need to be informed by measurement, reporting and verification (MRV) of greenhouse gas emissions reductions and other environmental, economic and social metrics. It discusses interlinked issues that must be considered in the expansion of PBC production: (i) available land; (ii) yield potential; (iii) integration into farming systems; (iv) R&D requirements; (v) utilisation options; and (vi) market systems and the socio-economic environment. It makes policy recommendations that would enable greater PBC deployment: (1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; (2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low-carbon bioenergy and bioproducts; (3) support innovation in biomass utilisation value chains; and (4) continue long-term, strategic R&D and education for positive environmental, economic and social sustainability impacts.

Diversity and Agronomic Performance of Lupinus mutabilis Germplasm in European and Andean Environments.

The introduction of Lupinus mutabilis (Andean lupin) in Europe will provide a new source of protein and oil for plant-based diets and biomass for bio-based products, while contributing to the improvement of marginal soils. This study evaluates for the first time the phenotypic variability of a large panel of L. mutabilis accessions both in their native environment and over two cropping conditions in Europe (winter crop in the Mediterranean region and summer crop in North-Central Europe), paving the way for the selection of accessions adapted to specific environments. The panel of 225 accessions included both germplasm pools from the Andean region and breeding lines from Europe. Notably, we reported higher grain yield in Mediterranean winter-cropping conditions (18 g/plant) than in the native region (9 g/plant). Instead, North European summer-cropping conditions appear more suitable for biomass production (up to 2 kg/plant). The phenotypic evaluation of 16 agronomical traits revealed significant variation in the panel. Principal component analyses pointed out flowering time, yield, and architecture-related traits as the main factors explaining variation between accessions. The Peruvian material stands out among the top-yielding accessions in Europe, characterized by early lines with high grain yield (e.g., LIB065, LIB072, and LIB155). Bolivian and Ecuadorian materials appear more valuable for the selection of genotypes for Andean conditions and for biomass production in Europe. We also observed that flowering time in the different environments is influenced by temperature accumulation. Within the panel, it is possible to identify both early and late genotypes, characterized by different thermal thresholds (600°C-700°C and 1,000-1,200°C GDD, respectively). Indications on top-yielding and early/late accessions, heritability of morpho-physiological traits, and their associations with grain yield are reported and remain largely environmental specific, underlining the importance of selecting useful genetic resources for specific environments. Altogether, these results suggest that the studied panel holds the genetic potential for the adaptation of L. mutabilis to Europe and provide the basis for initiating a breeding program based on exploiting the variation described herein.

Genomic Architecture and Evolution of the Cellulose synthase Gene Superfamily as Revealed by Phylogenomic Analysis.

The Cellulose synthase superfamily synthesizes cellulose and different hemicellulosic polysaccharides in plant cell walls. While much has been discovered about the evolution and function of these genes, their genomic architecture and relationship with gene (sub-)functionalization and evolution remains unclear. By using 242 genomes covering plant evolution from green algae to eudicots, we performed a large-scale analysis of synteny, phylogenetic, and functional data of the CesA superfamily. Results revealed considerable gene copy number variation across species and gene families, and also two patterns - singletons vs. tandem arrays - in chromosomic gene arrangement. Synteny analysis revealed exceptional conservation of gene architecture across species, but also lineage-specific patterns across gene (sub-)families. Synteny patterns correlated with gene sub-functionalization into primary and secondary CesAs and distinct CslD functional isoforms. Furthermore, a genomic context shift of a group of cotton secondary CesAs was associated with peculiar properties of cotton fiber synthesis. Finally, phylogenetics suggested that primary CesA sequences appeared before the secondary CesAs, while phylogenomic analyses unveiled the genomic trace of the CslD duplication that initiated the CslF family. Our results describe in detail the genomic architecture of the CesA superfamily in plants, highlighting its crucial relevance for gene diversification and sub-functionalization, and for understanding their evolution.

Synthetic bacterial community derived from a desert rhizosphere confers salt stress resilience to tomato in the presence of a soil microbiome.

The root bacterial microbiome is important for the general health of the plant. Additionally, it can enhance tolerance to abiotic stresses, exemplified by plant species found in extreme ecological niches like deserts. These complex microbe-plant interactions can be simplified by constructing synthetic bacterial communities or SynComs from the root microbiome. Furthermore, SynComs can be applied as biocontrol agents to protect crops against abiotic stresses such as high salinity. However, there is little knowledge on the design of a SynCom that offers a consistent protection against salt stress for plants growing in a natural and, therefore, non-sterile soil which is more realistic to an agricultural setting. Here we show that a SynCom of five bacterial strains, originating from the root of the desert plant Indigofera argentea, protected tomato plants growing in a non-sterile substrate against a high salt stress. This phenotype correlated with the differential expression of salt stress related genes and ion accumulation in tomato. Quantification of the SynCom strains indicated a low penetrance into the natural soil used as the non-sterile substrate. Our results demonstrate how a desert microbiome could be engineered into a simplified SynCom that protected tomato plants growing in a natural soil against an abiotic stress.

Detection and Analysis of Syntenic Quantitative Trait Loci Controlling Cell Wall Quality in Angiosperms.

Translational genomics can enable a quicker improvement of orphan crops toward novel agricultural applications, including the advancement of orphan biomass species for cultivation on marginal lands. In this sense, cell wall quality is a preeminent breeding target. However, tools to efficiently project genetic data on target traits across large sets of species are currently missing. This study aimed at closing this gap by developing a strategy to project a set of cell wall QTLs across a large group of plants by using genome synteny. This strategy is suited for large-scale analyses and detected 362 syntenic cell wall QTLs (SQTLs) across 74 angiosperms, including several (orphan) biomass species. SQTLs analyses revealed that they span large portions of the initial cell wall QTLs and are extensively conserved across diverse species. Moreover, numerous QTLs cell wall genes were conserved through SQTLs, including genes displaying allelic variation associated with cell wall composition. Functional analyses showed that highly conserved genes of SQTLs include important cell wall transcription factors and genes involved in the remodeling of cell wall polymers. For some of these gene families, SQTLs indicated the presence of differentially conserved genomic contexts for different gene members, highlighting their utility as a tool to pinpoint gene targets that maximize the likelihood of functional gene conservation. Overall, the results of this study can facilitate "universal" approaches for breeding (orphan) biomass crops, while the strategy for QTLs translation can be applied to other sets of traits and species, helping to unlock the potential of orphan species.

Cellulose synthesis complexes are homo-oligomeric and hetero-oligomeric in Physcomitrium patens.

The common ancestor of seed plants and mosses contained homo-oligomeric cellulose synthesis complexes (CSCs) composed of identical subunits encoded by a single CELLULOSE SYNTHASE (CESA) gene. Seed plants use different CESA isoforms for primary and secondary cell wall deposition. Both primary and secondary CESAs form hetero-oligomeric CSCs that assemble and function in planta only when all the required isoforms are present. The moss Physcomitrium (Physcomitrella) patens has seven CESA genes that can be grouped into two functionally and phylogenetically distinct classes. Previously, we showed that PpCESA3 and/or PpCESA8 (class A) together with PpCESA6 and/or PpCESA7 (class B) form obligate hetero-oligomeric complexes required for normal secondary cell wall deposition. Here, we show that gametophore morphogenesis requires a member of class A, PpCESA5, and is sustained in the absence of other PpCESA isoforms. PpCESA5 also differs from the other class A PpCESAs as it is able to self-interact and does not co-immunoprecipitate with other PpCESA isoforms. These results are consistent with the hypothesis that homo-oligomeric CSCs containing only PpCESA5 subunits synthesize cellulose required for gametophore morphogenesis. Analysis of mutant phenotypes also revealed that, like secondary cell wall deposition, normal protonemal tip growth requires class B isoforms (PpCESA4 or PpCESA10), along with a class A partner (PpCESA3, PpCESA5, or PpCESA8). Thus, P. patens contains both homo-oligomeric and hetero-oligomeric CSCs.

Bifidobacterium longum subsp. longum 51A attenuates intestinal injury against irinotecan-induced mucositis in mice.

Intestinal mucositis (IM) is a critical side-effect associated with antineoplastic therapy. Treatment available is only palliative and often not effective. However, alternative therapeutic strategies, such as probiotics, have attracted significant attention due to their immune-modulatory action in several diseases. Thus, the present study aims to elucidate the therapeutic potential of the probiotic strain Bifidobacterium longum 51A in a murine model of mucositis induced by irinotecan. Due to the scarcity of studies on dose-response and viability (probiotic vs paraprobiotic), we first evaluated which dose and cell viability would be most effective in treating mucositis. In this study, the oral pretreatment with viable B. longum 51A at a concentration of 1 × 109 CFU/mL reduced the daily disease activity index (p < 0.01), protected the intestinal architecture, preserved the length of the intestine (p < 0.05), and reduced intestinal permeability (p < 0.01), inflammation, and oxidative damage (p < 0.01) induced by irinotecan. Also, treatment with B. longum 51A increased the production of secretory immunoglobulin A (p < 0.05) in the intestinal fluid of mice with mucositis. Furthermore, B. longum 51A reversed the mucositis-induced increase in Enterobacteriaceae bacterial group in the gut (p < 0.01). In conclusion, these results showed that oral administration of B. longum 51A protects mice against intestinal damage caused by irinotecan, suggesting its use as a potential probiotic in therapy during mucositis.

A genome wide association study to dissect the genetic architecture of agronomic traits in Andean lupin (Lupinus mutabilis).

Establishing Lupinus mutabilis as a protein and oil crop requires improved varieties adapted to EU climates. The genetic regulation of strategic breeding traits, including plant architecture, growing cycle length and yield, is unknown. This study aimed to identify associations between 16 669 single nucleotide polymorphisms (SNPs) and 9 agronomic traits on a panel of 223 L. mutabilis accessions, grown in four environments, by applying a genome wide association study (GWAS). Seven environment-specific QTLs linked to vegetative yield, plant height, pods number and flowering time, were identified as major effect QTLs, being able to capture 6 to 20% of the phenotypic variation observed in these traits. Furthermore, two QTLs across environments were identified for flowering time on chromosome 8. The genes FAF, GAMYB and LNK, regulating major pathways involved in flowering and growth habit, as well as GA30X1, BIM1, Dr1, HDA15, HAT3, interacting with these pathways in response to hormonal and environmental cues, were prosed as candidate genes. These results are pivotal to accelerate the development of L. mutabilis varieties adapted to European cropping conditions by using marker-assisted selection (MAS), as well as to provide a framework for further functional studies on plant development and phenology in this species.

A G protein-coupled receptor-like module regulates cellulose synthase secretion from the endomembrane system in Arabidopsis.

Cellulose is produced at the plasma membrane of plant cells by cellulose synthase (CESA) complexes (CSCs). CSCs are assembled in the endomembrane system and then trafficked to the plasma membrane. Because CESAs are only active in the plasma membrane, control of CSC secretion regulates cellulose synthesis. We identified members of a family of seven transmembrane domain-containing proteins (7TMs) that are important for cellulose production during cell wall integrity stress. 7TMs are often associated with guanine nucleotide-binding (G) protein signaling and we found that mutants affecting the Gßγ dimer phenocopied the 7tm mutants. Unexpectedly, the 7TMs localized to the Golgi/trans-Golgi network where they interacted with G protein components. Here, the 7TMs and Gßγ regulated CESA trafficking but did not affect general protein secretion. Our results outline how a G protein-coupled module regulates CESA trafficking and reveal that defects in this process lead to exacerbated responses to cell wall integrity stress.

Breeding Targets to Improve Biomass Quality in Miscanthus.

Lignocellulosic crops are attractive bioresources for energy and chemicals production within a sustainable, carbon circular society. Miscanthus is one of the perennial grasses that exhibits great potential as a dedicated feedstock for conversion to biobased products in integrated biorefineries. The current biorefinery strategies are primarily focused on polysaccharide valorization and require severe pretreatments to overcome the lignin barrier. The need for such pretreatments represents an economic burden and impacts the overall sustainability of the biorefinery. Hence, increasing its efficiency has been a topic of great interest. Inversely, though pretreatment will remain an essential step, there is room to reduce its severity by optimizing the biomass composition rendering it more exploitable. Extensive studies have examined the miscanthus cell wall structures in great detail, and pinpointed those components that affect biomass digestibility under various pretreatments. Although lignin content has been identified as the most important factor limiting cell wall deconstruction, the effect of polysaccharides and interaction between the different constituents play an important role as well. The natural variation that is available within different miscanthus species and increased understanding of biosynthetic cell wall pathways have specified the potential to create novel accessions with improved digestibility through breeding or genetic modification. This review discusses the contribution of the main cell wall components on biomass degradation in relation to hydrothermal, dilute acid and alkaline pretreatments. Furthermore, traits worth advancing through breeding will be discussed in light of past, present and future breeding efforts.

Genetic Architecture of Flowering Time and Sex Determination in Hemp (Cannabis sativa L.): A Genome-Wide Association Study.

Flowering time and sex determination in hemp (Cannabis sativa L.) strongly influence fiber quality and seed production of this crop. The control of these traits is paramount for the breeding of new cultivars. Yet, little is known about the genetics underlying such complex traits and a better understanding requires in depth knowledge of the molecular mechanisms responsible for these traits. In this report, the genetic architecture of flowering time and sex determination in hemp was studied using a Genome-Wide Association Studies (GWAS) approach. Association studies were performed on a panel of 123 hemp accessions, tested in three contrasting environments, using a set of 600 K SNP markers. Altogether, eight QTLs were identified across environments; six for flowering time traits and two for sex determination. These QTLs covered genomic regions with 33 transcripts predicted to be involved in flowering and sex determination as well as a microRNA, miR156. Genes related to perception and transduction of light and transcription factors well-known to regulate flowering were identified in QTLs for flowering time traits. Transcription factors and genes involved in regulating the balance of phytohormones, specially auxins and gibberellic acid, were identified in QTLs for sex determination. Sex determination QTLs were associated with the development of male flowers in female plants and thus with the stability of sex determination in monecious plants. The present study elucidates relevant knowledge on the genetic mechanisms of flowering and sex determination traits in hemp, and provides new tools for hemp breeding.