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BackgroundColletotrichum fungi infect a wide diversity of monocot and dicot hosts, causing diseases on almost all economically important plants worldwide. Colletotrichum is also a suitable model for studying gene family evolution on a fine scale to uncover events in the genome associated with biological changes.ResultsHere we present the genome sequences of 30 Colletotrichum species covering the diversity within the genus. Evolutionary analyses revealed that the Colletotrichum ancestor diverged in the late Cretaceous in parallel with the diversification of flowering plants. We provide evidence of independent host jumps from dicots to monocots during the evolution of Colletotrichum, coinciding with a progressive shrinking of the plant cell wall degradative arsenal and expansions in lineage-specific gene families. Comparative transcriptomics of 4 species adapted to different hosts revealed similarity in gene content but high diversity in the modulation of their transcription profiles on different plant substrates. Combining genomics and transcriptomics, we identified a set of core genes such as specific transcription factors, putatively involved in plant cell wall degradation.ConclusionsThese results indicate that the ancestral Colletotrichum were associated with dicot plants and certain branches progressively adapted to different monocot hosts, reshaping the gene content and its regulation.

Melissa officinalis L. is a plant with different medicinal and culinary uses, which is considered one of the essential oils with the highest market value, mainly because of its low yield. The use of technologies that improve the extraction of this essential oil is justified. The study evaluated the use of cell wall degrading enzymes (CWDE) obtained from Pleorotus djamor to extract essential oil of Melissa officinalis L.. For the optimization of the enzymatic pre-treatment, the independent variables time and CWDE/H 2 O ratio were evaluated through central composite rotational design (CCRD). The essential oil extraction was carried out by hydrodistillation after pre-treatment. The results showed that the pre-treatment was able to increase the essential oil yield by 71 % and reduced energy consumption and CO2 emissions by 42 %, when applied for 60 minutes and CWDE/H 2 O ratio (25/450 mL.mL−1). Gas chromatography-mass spectrometry (GC/MS) was used to evaluate the essential oil composition. The majority of compounds were citral (Neral +Geranial). In addition, the increase of this compound was observed at about 24 %. The lemon balm plant cell wall was degraded. Considering the production and energy costs and increase yield as well as the quality of lemon balm essential oil, the application of CWDE was efficient. [Display omitted] • Multienzyme extract was extracted from the solid-state fermentation of P. djmour. • Association of enzymes with hydrostillation was considered an eco-friendly process. • Lignocellulosic enzymes acted on the cell wall of the trichomes. • Pretreatment on M. officinalis leaves increase of the essential oil yield by 71 %. • The concentration of Citral in the essential oil of Melissa officinalis increased. [ABSTRACT FROM AUTHOR]

Lignin fluorescence in plant cell walls significantly interferes with Raman spectroscopic signals, resulting in compromised analytical accuracy and resolution. To address this issue, a strategy was implemented to both reduce the absolute lignin content in samples and prepare thinner plant tissue sections. This approach involved embedding plant samples in LR White resin, complemented by an ultrathin sectioning technique. Additionally, algorithms were developed to eliminate the impact of resin spectra on the imaging process. These advancements collectively enhanced the performance of Raman spectroscopy by effectively diminishing the disruptive effects of lignin fluorescence. Further analysis with confocal laser scanning microscopy (CLSM) elucidated the presence of aggregation-induced luminescence (AIE) in plant tissues, revealing a direct correlation with lignin concentration. These findings not only offer a new perspective for the application of Raman spectroscopy in plant science, but also pave the way for advancements in tip-enhanced Raman spectroscopy (TERS) detection. [ABSTRACT FROM AUTHOR]

Summary: Polysaccharide structural complexity not only influences cell wall strength and extensibility but also hinders pathogenic and biotechnological attempts to saccharify the wall. In certain species and tissues, glucuronic acid side groups on xylan exhibit arabinopyranose or galactose decorations whose genetic and evolutionary basis is completely unknown, impeding efforts to understand their function and engineer wall digestibility.Genetics and polysaccharide profiling were used to identify the responsible loci in Arabidopsis and Eucalyptus from proposed candidates, while phylogenies uncovered a shared evolutionary origin. GH30‐family endo‐glucuronoxylanase activities were analysed by electrophoresis, and their differing specificities were rationalised by phylogeny and structural analysis.The newly identified xylan arabinopyranosyltransferases comprise an overlooked subfamily in the GT47‐A family of Golgi glycosyltransferases, previously assumed to comprise mainly xyloglucan galactosyltransferases, highlighting an unanticipated adaptation of both donor and acceptor specificities. Further neofunctionalisation has produced a Myrtaceae‐specific xylan galactosyltransferase. Simultaneously, GH30 endo‐glucuronoxylanases have convergently adapted to overcome these decorations, suggesting a role for these structures in defence. The differential expression of glucuronoxylan‐modifying genes across Eucalyptus tissues, however, hints at further functions.Our results demonstrate the rapid adaptability of biosynthetic and degradative carbohydrate‐active enzyme activities, providing insight into plant–pathogen interactions and facilitating plant cell wall biotechnological utilisation. See also the Commentary on this article by Mortimer & Scheller, 244: 749–751. [ABSTRACT FROM AUTHOR]

NAC‐domain transcription factors (TFs) are plant‐specific transcriptional regulators playing crucial roles in plant secondary cell wall (SCW) biosynthesis. SCW is important for plant growth and development, maintaining plant morphology, providing rigid support, ensuring material transportation and participating in plant stress responses as a protective barrier. However, the molecular mechanisms underlying SCW in eggplant have not been thoroughly explored. In this study, the NAC domain TFs SmNST1 and SmNST2 were cloned from the eggplant line 'Sanyue qie′. SmNST1 and SmNST2 expression levels were the highest in the roots and stems. Subcellular localization analysis showed that they were localized in the cell membrane and nucleus. Their overexpression in transgenic tobacco showed that SmNST1 promotes SCW thickening. The expression of a set of SCW biosynthetic genes for cellulose, xylan and lignin, which regulate SCW formation, was increased in transgenic tobacco. Bimolecular fluorescence and luciferase complementation assays showed that SmNST1 interacted with SmNST2 in vivo. Yeast one‐hybrid, electrophoretic mobility shift assay (EMSA) and Dual‐luciferase reporter assays showed that SmMYB26 directly bound to the SmNST1 promoter and acted as an activator. SmNST1 and SmNST2 interact with the SmMYB108 promoter and repress SmMYB108 expression. Altogether, we showed that SmNST1 positively regulates SCW formation, improving our understanding of SCW biosynthesis transcriptional regulation. Summary Statement: In this study, we found that SmMYB26, as an activator, directly bound to the SmNST1 promoter, and SmNST1 positively regulates SCW formation in eggplant. [ABSTRACT FROM AUTHOR]

ABSTRACT As an evolutionary achievement of almost all terrestrial plants, lignin biosynthesis is essential for various mechanical and physiological processes. Possible effects of plant cell wall lignification on large‐scale vegetation distribution are, however, not yet fully understood. Here, we present double‐stained, wood anatomical stem measurements of 207 perennial herbs (Potentilla pamirica Wolf), which were collected between 5550 and 5850 m asl on the north‐western Tibetan Plateau in Ladakh, India. We also measured changes in situ root zone and surface air temperatures along the sampling gradient and applied piecewise structural equation models to assess direct and indirect relationships between the age and size of plants, the degree of cell wall lignification in their stems, and the elevation at which they were growing. Based on the world's highest‐occurring vascular plants, the Pamir Cinquefoils, we demonstrate that the amount of lignin in the secondary cell walls decreases significantly with increasing elevation (r = −0.73; p < 0.01). Since elevation is a proxy for temperature, our findings suggest a thermal constrain on lignin biosynthesis at the cold range limit of woody plant growth. [ABSTRACT FROM AUTHOR]

SUMMARY Lignification of the cell wall in pear (Pyrus) fruit results in the formation of stone cells, which affects the texture and quality of the fruit. However, it is still unclear that how different transcription factors (TFs) work together to coordinate the synthesis and deposition of lignin. Here, we examined the transcriptome of pear varieties with different stone cell contents and found a key TF (PbAGL7) that can promote the increase of stone cell contents and secondary cell wall thicknesses. In addition, PbAGL7 can facilitate the expression level of lignin biosynthesis‐related genes and accelerate the lignin biosynthesis in pear fruit and Arabidopsis. However, PbAGL7 did not directly bind to the promoters of PbC3H1 and PbHCT17 which are crucial genes involved in lignin biosynthesis. On the other hand, yeast two‐hybrid (Y2H) library showed that PbNAC47 and PbMYB73 interacted with PbAGL7 in the nucleus. PbNAC47 and PbMYB73 also increased the stone cell and lignin contents, and upregulated the expressions of PbC3H1 and PbHCT17 by binding to the SNBE and AC elements, respectively. Moreover, PbNAC47 also interacted with PbMYB73 to form PbAGL7–PbNAC47–PbMYB73 complex. This complex significantly activated the expression levels of PbC3H1 and PbHCT17 and promoted lignin biosynthesis to form stone cells in pear fruit. Overall, our study provides new insights into the molecular mechanism of TFs that coordinately regulate the stone cell formation in pear fruit and extend our knowledge to understand cell wall lignification in plants. [ABSTRACT FROM AUTHOR]

Background: Lignin is an aromatic polymer deposited in secondary cell walls of higher plants to provide strength, rigidity, and hydrophobicity to vascular tissues. Due to its interconnections with cell wall polysaccharides, lignin plays important roles during plant growth and defense, but also has a negative impact on industrial processes aimed at obtaining monosaccharides from plant biomass. Engineering lignin offers a solution to this issue. For example, previous work showed that heterologous expression of a coliphage S-adenosylmethionine hydrolase (AdoMetase) was an effective approach to reduce lignin in the model plant Arabidopsis. The efficacy of this engineering strategy remains to be evaluated in bioenergy crops. Results: We studied the impact of expressing AdoMetase on lignin synthesis in sorghum (Sorghum bicolor L. Moench). Lignin content, monomer composition, and size, as well as biomass saccharification efficiency were determined in transgenic sorghum lines. The transcriptome and metabolome were analyzed in stems at three developmental stages. Plant growth and biomass composition was further evaluated under field conditions. Results evidenced that lignin was reduced by 18% in the best transgenic line, presumably due to reduced activity of the S-adenosylmethionine-dependent O-methyltransferases involved in lignin synthesis. The modified sorghum features altered lignin monomer composition and increased lignin molecular weights. The degree of methylation of glucuronic acid on xylan was reduced. These changes enabled a ~20% increase in glucose yield after biomass pretreatment and saccharification compared to wild type. RNA-seq and untargeted metabolomic analyses evidenced some pleiotropic effects associated with AdoMetase expression. The transgenic sorghum showed developmental delay and reduced biomass yields at harvest, especially under field growing conditions. Conclusions: The expression of AdoMetase represents an effective lignin engineering approach in sorghum. However, considering that this strategy potentially impacts multiple S-adenosylmethionine-dependent methyltransferases, adequate promoters for fine-tuning AdoMetase expression will be needed to mitigate yield penalty. [ABSTRACT FROM AUTHOR]

Lignin is a crucial component of plant cell walls, supporting plant growth by providing mechanical strength, aiding water transport, and enhancing resistance to pathogens. Despite extensive research on lignin biosynthesis as a renewable resource, understanding the transport and deposition of its monomers remains challenging. In this study, a novel precursor monomer was designed, SALK (alkyne-tagged sinapyl alcohol surrogate), for tracking and localizing lignin in flax cells, aiming to explore the in vivo lignification process. First, the dehydrogenation polymer (DHP) of SALK was synthesized and its biocompatibility was successfully verified. After click chemistry to label fluorescent dyes, incorporation of novel lignin monomers during the polymerization process was detected and imaged successfully. The results indicated that the chemical reporter could provide detailed localization information during polymerization. It was found that lignification in the bast fiber (R) cells and fiber tracheid (FT) cells of flax was different. FT cells closer to the pith showed higher maturity and lower lignification degree. While R cells, regardless of their proximity to the pith, show a relatively consistent lignification trend. At the single-cell level, lignin deposition initiates at cell corners and the middle lamella, followed by secondary cell wall, with the highest lignin content in the secondary wall of mature cells. The results of this work reveal the potential of chemical reporters in providing detailed insights into the in vivo lignification process, advancing the technology for studying the formation and function of plant cell walls. [ABSTRACT FROM AUTHOR]

Trichoderma spp. is known for its ability to enhance plant growth and suppress disease, but the mechanisms for its interaction with host plants and pathogens remain unclear. This study investigated the transcriptomics and metabolomics of peanut plants (Arachis hypogaea L.) inoculated with Trichoderma harzianum QT20045, in the absence and presence of the stem rot pathogen Sclerotium rolfsii JN3011. Under the condition without pathogen stress, the peanut seedlings inoculated with QT20045 showed improved root length and plant weight, increased indole acetic acid (IAA) production, and reduced ethylene level, with more active 1-aminocyclopropane-1-carboxylate acid (ACC) synthase (ACS) and ACC oxidase (ACO), compared with the non-inoculated control. Under the pathogen stress, the biocontrol efficacy of QT20045 against S. rolfsii was 78.51%, with a similar effect on plant growth, and IAA and ethylene metabolisms to the condition with no biotic stress. Transcriptomic analysis of peanut root revealed that Trichoderma inoculation upregulated the expression of certain genes in the IAA family but downregulated the genes in the ACO family (AhACO1 and AhACO) and ACS family (AhACS3 and AhACS1) consistently in the absence and presence of pathogens. During pathogen stress, QT20045 inoculation leads to the downregulation of the genes in the pectinesterase family to keep the host plant's cell wall stable, along with upregulation of the AhSUMM2 gene to activate plant defense responses. In vitro antagonistic test confirmed that QT20045 suppressed S. rolfsii growth through mechanisms of mycelial entanglement, papillary protrusions, and decomposition. Our findings highlight that Trichoderma inoculation is a promising tool for sustainable agriculture, offering multiple benefits from pathogen control to enhanced plant growth and soil health. [ABSTRACT FROM AUTHOR]

SUMMARY Carrot (Daucus carota) is one of the most popular and nutritious vegetable crops worldwide. However, significant yield losses occur every year due to leaf blight, a disease caused by a fungal pathogen (Alternaria dauci). Past research on resistance to leaf blight disease in carrots has been slow because of the low‐quality genome assemblies of both carrot and the pathogen. Here, we report the greatly improved assemblies and annotations of telomere‐to‐telomere (T2T) reference genomes of carrot DH13M14 (451.04 Mb) and A. dauci A2016 (34.91 Mb). Compared with the previous carrot genome versions, our assembly featured notable improvements in genome size, continuity, and completeness of centromeres and telomeres. In addition, we generated a time course transcriptomic atlas during the infection of carrots by A. dauci and captured their dynamic gene expression reprogramming during the interaction process. During infection, A. dauci genes encoding effectors and enzymes responsible for the degradation of plant cell wall components, e.g., cellulose and pectin, were identified, which appeared to increase pathogenic ability through upregulation. In carrot, the coordinated gene expression of components of pattern‐ and effector‐triggered immunity (PTI and ETI) in response to A. dauci attack was characterized. The biosynthesis or signal transduction of plant hormones, including JA, SA, and ethylene, was also involved in the carrot response to A. dauci. This work provides a foundation for understanding A. dauci pathogenic progression and carrot defense mechanisms to improve carrot resistance to leaf blight disease. The Carrot Database (CDB) developed also provides a useful resource for the carrot community. [ABSTRACT FROM AUTHOR]

Plant cell walls are essential for growth. The cell wall hemicellulose xyloglucan (XyG) is produced in the Golgi apparatus before secretion. Loss of the Arabidopsis galactosyltransferase MURUS3 (MUR3) decreases XyG d -galactose side chains and causes intracellular aggregations and dwarfism. It is unknown how changing XyG synthesis can broadly impact organelle organization and growth. We show that intracellular aggregations are not unique to mur3 and are found in multiple mutant lines with reduced XyG D -galactose side chains. mur3 aggregations disrupt subcellular trafficking and induce formation of intracellular cell-wall-like fragments. Addition of d -galacturonic acid onto XyG can restore growth and prevent mur3 aggregations. These results indicate that the presence, but not the composition, of XyG side chains is essential, likely by ensuring XyG solubility. Our results suggest that XyG polysaccharides are synthesized in a highly substituted form for efficient secretion and then later modified by cell-wall-localized enzymes to fine-tune cell wall properties. [Display omitted] • A reduction in xyloglucan (XyG) side chains causes intracellular aggregations • Intracellular aggregations form during cell expansion and disrupt secretion • An alternate XyG side chain restores secretion but not cell wall composition Hoffmann and McFarlane show that the plant cell wall polysaccharide xyloglucan requires side chains for effective secretion following its biosynthesis in the Golgi apparatus, as production of side-chain-deficient xyloglucan causes intracellular aggregations of proteins and polysaccharides. These results highlight the importance of polysaccharide structure for efficient secretion to the cell wall. [ABSTRACT FROM AUTHOR]

This study investigated arsenic (As) concentrations in diverse environmental components and their potential impact on the health risks faced by residents of the arsenic (As)-contaminated Nadia district in West Bengal, India. A random selection of 182 cattle and 255 goats from 40 livestock farmers in the district revealed that both animals and humans were naturally exposed to elevated arsenic levels through contaminated drinking water, foods, grasses, concentrate feeds, various fodder tree leaves, and other food/feed resources. The mean As concentration in roughages (483.18 µg/kg DM) was significantly higher (p < 0.001) than in tree leaves (391.53 µg/kg DM), and concentrate feed/ingredients (186.66 µg/kg DM). Pond water exhibited higher arsenic levels (106.11 µg/L) compared to shallow tube well water (47.96 µg/L) and deep tube well water/tap water (10.64 µg/L and 10.04 µg/L, respectively). The mean arsenic concentration in soils DM of fodder fields, crop fields, and grassland was 10.25, 10.58, and 10.20 mg/kg, respectively. It was observed that protein-rich feeds had lower levels of arsenic accumulation (p < 0.048), while fiber-rich feeds containing more cellulose, hemicellulose, and lignin had higher arsenic levels (p < 0.017). Goats consumed 73.46% more arsenic per kg body weight compared to dairy cows. Although chronic and sub-chronic arsenic exposure in the district did not typically manifest symptoms or visible signs in ruminant animals, concentrations in the hair and feces of both cattle and goats exceeded normal values. Cattle feces had significantly higher arsenic (410.43 µg/kg DM) levels (p < 0.001) than goat feces (227.00 µg/kg DM), and arsenic concentration in cattle hair (1917.74 µg/kg DM) was also significantly greater (p < 0.001) than goat hair (1435.74 µg/kg DM). Arsenic levels in milk samples from both species were below 10 µg/kg. Liver (356.02 µg/kg DM) and kidney (317.22 µg/kg DM) contained significantly higher (p < 0.001) levels of arsenic compared to muscle (204.23 µg/kg DM), and bone (161.98 µg/kg DM) in local meat-type adult male goats. The skin accumulated the highest amount of arsenic (576.24 µg/kg DM) among the non-edible parts of the goat carcass. The cumulative cancer risk value for adults was 4.96 × 10−3, exceeding the threshold value (1 × 10−6). This suggests a significant risk of cancer development for the population in arsenic-affected areas. Non-cancer risks (hazard indexes) were estimated at 11.01 for adults. Our observations revealed that the highest bioaccumulation of arsenic occurred in the hair of cows, and goats in the examined localities. The biotransformation factor (BTF) for hair was much higher compared to other excreted samples from both species. The calculated BTF followed the order: hair > feces > milk for cows and goats. Livestock farmers in Nadia district are advised to carefully select feed resources, prioritizing those high in crude protein and low in neutral detergent fiber, and they should provide drinking water from deep aquifers to ensure the safety of milk and meat for human consumption. [ABSTRACT FROM AUTHOR]

Nanocellulose is a robust material with a broad spectrum of potential applications. Manufacturing nanocellulose has garnered greater interest recently and is currently the European economy's second-highest priority. It is possible to extract from plants' biomass using various methods, which are divided broadly into various categories. The kind of biomass, the desired qualities of the nanocellulose, and the production size all have a role in selecting the pretreatment and extraction process. Several pretreatment and extraction techniques for nanocellulose from plant biomass are covered in this review, along with the variables that affect method selection. Developing scalable, effective production processes for nanocellulose is crucial for commercializing technologies. The current processes to create nanocellulose are still somewhat inefficient, and industrial scale-up is challenging. Future studies are likely to focus on efficient, scalable techniques for reducing down cell walls from plants and lower-cost nanocellulose synthesis using clean energy sources. [ABSTRACT FROM AUTHOR]

Some Basidiomycete fungi are important plant pathogens, and certain species have been associated with the grapevine trunk disease esca. We present the genomes of 4 species associated with esca: Fomitiporia mediterranea , Fomitiporia polymorpha , Tropicoporus texanus , and Inonotus vitis. We generated high-quality phased genome assemblies using long-read sequencing. The genomic and functional comparisons identified potential virulence factors, suggesting their roles in disease development. Similar to other white-rot fungi known for their ability to degrade lignocellulosic substrates, these 4 genomes encoded a variety of lignin peroxidases and carbohydrate-active enzymes (CAZymes) such as CBM1, AA9, and AA2. The analysis of gene family expansion and contraction revealed dynamic evolutionary patterns, particularly in genes related to secondary metabolite production, plant cell wall decomposition, and xenobiotic degradation. The availability of these genomes will serve as a reference for further studies of diversity and evolution of virulence factors and their roles in esca symptoms and host resistance. [ABSTRACT FROM AUTHOR]

Maize production and quality are affected by infection with plant pathogens. One of the maize's essential and main diseases is downy mildew caused by Peronosclerospora spp. Downy mildew is a limiting factor in increasing production and can reduce production by 80-100%. It is because the affected plant cannot produce cobs. Pathogens obtain nutrients from the host cell, which can kill the cell and damage the surrounding tissues, resulting in visible downy mildew symptoms. Boron (B) plays a role in forming phloem, increasing the fruit's number, weight, bunch weight, and diameter. The primary function of B at the molecular level is the cross-linking of pectin in the plant cell wall. Ramnogalacturonan II (RG II) is a pectic polysaccharide that contributes to the mechanical strength and properties of the primary wall cross-linked by borate diesters. Phosphorus (P) controls the downsides in the greenhouse and field conditions. This study aims to measure changes in chlorophyll index, P and B uptakes in downy mildew affected plants. The field experiment used a group randomized design with six natural phosphate (FA) application treatments and four groups of borax doses as replicates. The results showed that the downy mildew decreased the chlorophyll index of the leaves at different levels of attack. The results of P concentration according to the position of healthy plant leaves were significantly different due to P treatment. In contrast to concentration B, there is no real difference. P and B uptake results in downy mildew-infested plants showed a significant difference only in P uptake in leaves with 1 FA treatment. [ABSTRACT FROM AUTHOR]

Expansins comprise an ancient group of cell wall proteins ubiquitous in land plants and their algal ancestors. During cell growth, they facilitate passive yielding of the wall's cellulose networks to turgor-generated tensile stresses, without evidence of enzymatic activity. Expansins are also implicated in fruit softening and other developmental processes and in adaptive responses to environmental stresses and pathogens. The major expansin families in plants include α-expansins (EXPAs), which act on cellulose-cellulose junctions, and β-expansins, which can act on xylans. EXPAs mediate acid growth, which contributes to wall enlargement by auxin and other growth agents. The genomes of diverse microbes, including many plant pathogens, also encode expansins designated expansin-like X. Expansins are proposed to disrupt noncovalent bonding between laterally aligned polysaccharides (notably cellulose), facilitating wall loosening for a variety of biological roles. [ABSTRACT FROM AUTHOR]

Cryptococcus neoformans and Cryptococcus gattii have been isolated from several different environmental sources, including several different tree species. This could indicate that the two species are ubiquitous in the same way as Saccharomyces cerevisiae. Laboratory infection studies have established that the two species can colonize the surface and inside of different plant species. However, the nature and number of studies make it difficult to form a general hypothesis about the relationship between C. neoformans/gattii and plants. Despite being reported, plant disease from infections is not well documented, and only from mated infection mixes. Interestingly, environmental isolates are often only of one of the two mating types. The profile of carbohydrate-active enzymes (CAZymes) encoded in the genomes of C. neoformans and C. gattii , makes it unlikely that they can degrade the plant cell wall as plant pathogens. Instead, they have the pectinolytic potential to live as commensal epi- or endophytes. While the opportunistic human pathogens Cryptococcus neoformans and Cryptococcus gattii are often isolated from plants and plant-related material, evidence suggests that these Cryptococcus species do not directly infect plants. Studies find that plants are important for Cryptococcus mating and dispersal. However, these studies have not provided enough detail about how plants and these fungi interact, especially in ways that could show the fungi are capable of causing disease. This review synthesizes recent findings from studies utilizing different plant models associated with the ecology of C. neoformans and C. gattii. Unanswered questions about their environmental role are highlighted. Overall, current research indicates that Cryptococcus utilizes plants as a substrate rather than harming them, arguing against Cryptococcus as a genuine plant pathogen. We hypothesize that plants represent reservoirs that aid dispersal, not hosts vulnerable to infection. [ABSTRACT FROM AUTHOR]

SUMMARY: Xylan is one of the major hemicelluloses in plant cell walls and its xylosyl backbone is often decorated at O‐2 with glucuronic acid (GlcA) and/or methylglucuronic acid (MeGlcA) residues. The GlcA/MeGlcA side chains may be further substituted with 2‐O‐arabinopyranose (Arap) or 2‐O‐galactopyranose (Gal) residues in some plant species, but the enzymes responsible for these substitutions remain unknown. During our endeavor to investigate the enzymatic activities of Arabidopsis MUR3‐clade members of the GT47 glycosyltransferase family, we found that one of them was able to transfer Arap from UDP‐Arap onto O‐2 of GlcA side chains of xylan, and thus it was named xylan 2‐O‐arabinopyranosyltransferase 1 (AtXAPT1). The function of AtXAPT1 was verified in planta by its T‐DNA knockout mutation showing a loss of the Arap substitution on xylan GlcA side chains. Further biochemical characterization of XAPT close homologs from other plant species demonstrated that while the poplar ones had the same catalytic activity as AtXAPT1, those from Eucalyptus, lemon‐scented gum, sea apple, 'Ohi'a lehua, duckweed and purple yam were capable of catalyzing both 2‐O‐Arap and 2‐O‐Gal substitutions of xylan GlcA side chains albeit with differential activities. Sequential reactions with XAPTs and glucuronoxylan methyltransferase 3 (GXM3) showed that XAPTs acted poorly on MeGlcA side chains, whereas GXM3 could efficiently methylate arabinosylated or galactosylated GlcA side chains of xylan. Furthermore, molecular docking and site‐directed mutagenesis analyses of Eucalyptus XAPT1 revealed critical roles of several amino acid residues at the putative active site in its activity. Together, these findings establish that XAPTs residing in the MUR3 clade of family GT47 are responsible for 2‐O‐arabinopyranosylation and 2‐O‐galactosylation of GlcA side chains of xylan. Significance Statement: Xylan is one of the major hemicelluloses in plant cell walls and its GlcA side chains may be further substituted with 2‐O‐Arap or 2‐O‐Gal residues. We have uncovered the functions of a subgroup of MUR3‐clade GT47 members in catalyzing the transfer of 2‐O‐Arap and/or 2‐O‐Gal onto GlcA side chains of xylan, which expands our understanding of glycosyltransferases involved in xylan substitutions. [ABSTRACT FROM AUTHOR]

The building and construction sector is the largest emitter of greenhouse gases, accounting for 37% of global emissions. The production and use of materials such as cement, steel, and aluminum contribute significantly to this carbon footprint. Utilizing valorized agricultural by-products, such as hemp shiv and sunflower pith, in construction can enhance the insulating properties of materials and reduce their environmental impact by capturing CO2. Additionally, during the formulation process, molecules such as polyphenols and sugars are released, depending on process parameters like pH and temperature. In some cases, these releases can cause issues, such as delaying the hardening of agro-based concrete or serving as binding agents in binderless particle boards. This study focuses on the molecules released during the processing of these materials, with particular attention to the effects of pH and temperature, and the modifications to the plant particles resulting from these conditions. Physical, chemical, and morphological analyses were conducted on the treated hemp shiv particles (HS1 and HS2). No physical or morphological differences were observed between the samples. However, chemical differences, particularly in the lignin and soluble compound content, were noted and were linked to the release of plant substances during the process. [ABSTRACT FROM AUTHOR]

This study demonstrates evidence that the mass transfer process of an enzyme (a biocatalyst) is the rate‐limiting step in the starch hydrolysis reaction during food digestion. The significance of this work has been to compare the reaction rate of starch hydrolysis by salivary enzymes with the mass transfer rate of rate‐limiting enzymes. This research has applied mass transfer and reaction engineering theory in a quantitative study of starch hydrolysis, and a dimensionless group, the Damköhler number (Da), has been calculated based on glucose measurements from a beaker and stirrer system. The values of the Da number in this study (0.3–19) indicate that both the time constant for mass transfer and the time constant for reaction are significant parameters. Scanning electron microscopy images emphasize that compression (simulated mastication) helps to break the plant cell wall of starch. Mass‐transfer resistance needs to be considered during food digestion studies. The Da numbers are significantly affected by both compression forces (internal mass‐transfer coefficients) and stirrer speeds (external mass‐transfer coefficients) in this beaker and stirrer system. [ABSTRACT FROM AUTHOR]

Pectin is a vital component of plant cell walls and its methylation process is regulated by pectin methylesterase inhibitors (PMEIs). PMEIs regulate the structural and functional modifications of cell walls in plants and play an important role in plant processes such as seed germination, fruit ripening, and stress response. Although the PMEI gene family has been well characterized in model plants, the understanding of its molecular evolution and biological functions in watermelon remains limited. In this study, 60 ClPMEI genes were identified and characterized, revealing their dispersion on multiple chromosomes. Based on a systematic developmental analysis, these genes were classified into three subfamilies, which was further supported by the exon, intron, and conserved motif distribution. Analysis of cis-elements and expression patterns indicated that ClPMEIs might be involved in regulating the tolerance of watermelon to various abiotic stresses. Moreover, distinct ClPMEI genes exhibit specific functions under different abiotic stresses. For example, ClPMEI51 and ClPMEI54 showed a significant upregulation in expression levels during the late stage of drought treatments, whereas ClPMEI3 and ClPMEI12 displayed a significant downregulation under low-temperature induction. Subcellular localization prediction and analysis revealed that the ClPMEI family member proteins were localized to the cell membrane. This study provided an important foundation for the further exploration of the functions of ClPMEI genes in watermelon. [ABSTRACT FROM AUTHOR]

Bamboo resources have garnered significant global attention due to their excellent capacity for regeneration and high yield. Rhombic-spot disease, a substantial threat to fishscale bamboo (Phyllostachys heteroclada), is primarily caused by Neostagonosporella sichuanensis. This study first reported the genome assemblies and characteristics of two N. sichuanensis isolates using PacBio and Illumina sequencing platforms. The genomes of N. sichuanensis strain SICAUCC 16-0001 and strain SICAUCC 23-0140, with sizes of 48.0 Mb and 48.4 Mb, respectively, revealed 10,289 and 10,313 protein-coding genes. Additionally, they contained 34.99 and 34.46% repetitive sequences within ATrich regions, with notable repeat-induced point mutation activity. Comparative genome analysis identified 1,049 contracted and 45 expanded gene families in the genome of N. sichuanensis, including several related to pathogenicity. Several gene families involved in mycotoxin metabolism, secondary metabolism, sterol biosynthesis and transport, and cell wall degradation were contracted. Compared to most analyzed necrotrophic, hemibiotrophic, and phaeosphaeriacous pathogens, the genomes of two N. sichuanensis isolates exhibited fewer secondary metabolite enzymes, carbohydrate-active enzymes, plant cell wall degrading enzymes, secreted proteins, and effectors. Comparative genomics analysis suggested that N. sichuanensis shares more similar characteristics with hemibiotrophic pathogens. Based on single carbon source tests, N. sichuanensis strains demonstrated a higher potential for xylan decomposition than pectin and cellulose. The proportion of cell wall-degrading enzyme effectors occupied a high proportion of the total effectors of the N. sichuanensis genomes. These findings provide valuable insights into uncovering the pathogenesis of N. sichuanensis toward the efficient management of rhombic-spot disease of fishscale bamboo. [ABSTRACT FROM AUTHOR]

This article discusses the relationship between root cortical parenchyma wall width (CPW) and plant functioning under drought conditions. The study found that thicker CPW in maize roots promotes growth and yield under suboptimal water and nitrogen supply. The authors used a functional-structural root anatomy model to predict the effects of increased CPW on root respiration and conducted field experiments to confirm their findings. They also identified potential genes associated with CPW changes and suggested that thicker CPW allows for deeper rooting, which enhances water uptake and plant performance under drought. The article highlights the importance of understanding root cortical cell structures and their impact on plant adaptation to stressful environments. [Extracted from the article]

Bacterial biofilm formation and attachment to hosts are mediated by carbohydrate-binding lectins, exopolysaccharides, and their interactions in the extracellular matrix (ECM). During tomato infection Ralstonia pseudosolanacearum (Rps) GMI1000 highly expresses three lectins: LecM, LecF, and LecX. The latter two are uncharacterized. We evaluated the roles in bacterial wilt disease of LecF, a fucose-binding lectin, LecX, a xylose-binding lectin, and the Rps exopolysaccharide EPS I. Interestingly, single and double lectin mutants attached to tomato roots better and formed more biofilm under static conditions in vitro. Consistent with this finding, static bacterial aggregation was suppressed by heterologous expression of lecFGMI1000 and lecXGMI1000 in other Ralstonia strains that naturally lack these lectins. Crude ECM from a ΔlecF/X double mutant was more adhesive than the wild-type ECM, and LecF and LecX increased Rps attachment to ECM. The enhanced adhesiveness of the ΔlecF/X ECM could explain the double mutant's hyper-attachment in static conditions. Unexpectedly, mutating lectins decreased Rps attachment and biofilm viscosity under shear stress, which this pathogen experiences in plant xylem. LecF, LecX, and EPS I were all essential for biofilm development in xylem fluid flowing through cellulose-coated microfluidic channels. These results suggest that under shear stress, LecF and LecX increase Rps attachment by interacting with the ECM and plant cell wall components like cellulose. In static conditions such as on root surfaces and in clogged xylem vessels, the same lectins suppress attachment to facilitate pathogen dispersal. Thus, Rps lectins have a dual biological function that depends on the physical environment. Author summary: Bacterial wilt diseases caused by Ralstonia species inflict significant losses on diverse, globally important agricultural plants. The pathogen first colonizes roots and ultimately the water-transporting xylem. There it attaches to host cell walls and other bacterial cells to form biofilms that eventually block xylem vessels and disrupt sap flow. It is not well known how Ralstonia spp. modulate attachment, but precise control of both attachment and dispersal is critical for successful host colonization over the disease cycle. Excessive adhesion could trap bacteria in a toxic or nutrient-depleted environment. Conversely, insufficient adhesion in a flowing environment could displace bacteria from an optimal niche. We provide evidence of dual, environment-specific roles of carbohydrate-binding lectins and exopolysaccharide EPS I in Ralstonia pseudosolanacearum (Rps) attachment. In static conditions, which Rps experiences on a host root, two lectins suppress bacterial aggregation and adhesion to roots. However, in flowing conditions, which Rps experiences in healthy xylem vessels, the same two lectins and EPS I are essential for biofilm development. The lectins increase the biofilm viscosity and support colony structural integrity, likely by interacting with polysaccharides in the biofilm matrix. This novel multifunctionality of bacterial lectins reveals how pathogens adapt to a physically dynamic host environment. [ABSTRACT FROM AUTHOR]

Plant cell walls (PCWs) are intricate structures with complex polysaccharides delivered by distinct trafficking routes. Unravelling the intricate trafficking pathways of polysaccharides and proteins involved in PCW biosynthesis is a crucial first step towards understanding the complexities of plant growth and development. This study investigated the feasibility of employing a multi-modal approach that combines transmission electron microscopy (TEM) with molecular-genetic tagging and antibody labelling techniques to differentiate these pathways at the nanoscale. The genetically encoded electron microscopy (EM) tag APEX2 was fused to Arabidopsis thaliana cellulose synthase 6 (AtCESA6) and Nicotiana alata ARABINAN DEFICIENT LIKE 1 (NaARADL1), and these were transiently expressed in Nicotiana benthamiana leaves. APEX2 localization was then combined with immunolabeling using pectin-specific antibodies (JIM5 and JIM7). Our results demonstrate distinct trafficking patterns for AtCESA6 and NaARADL, with AtCESA6 localized primarily to the plasma membrane and vesicles, while NaARADL1 was found in the trans-Golgi network and cytoplasmic vesicles. Pectin epitopes were observed near the plasma membrane, inGolgi-associated vesicles, and in secretory vesicle clusters (SVCs) with both APEX2 constructs. Notably, JIM7 labelling was found in vesicles adjacent to APEX2-AtCESA6 vesicles, suggesting potential co-trafficking. This integrative approach offers a powerful tool for elucidating the dynamic interactions between PCW components at the nanoscale level. The methodology presented here facilitates the precise mapping of protein and polysaccharide trafficking pathways, advancing our understanding of PCW biosynthesis and providing avenues for future research aimed at engineering plant cell walls for various applications. [ABSTRACT FROM AUTHOR]

Cellulosic microfibrils in plant cell walls are largely ensheathed and probably tethered by hydrogen-bonded hemicelluloses. Ensheathing may vary developmentally as hemicelluloses are peeled to enable cell expansion. We characterised a simple method to quantify ensheathed versus naked cellulosic surfaces based on the ability to adsorb a radiolabelled ‘cellulose-complementary oligosaccharide’, [³H]cellopentaitol. Filter-paper (cellulose) adsorbed 40% and >80% of aqueous 5 nM [³H]cellopentaitol within ∼1 and ∼20 h respectively. When [³H]cellopentaitol was rapidly dried onto filter-paper, ∼50% of it was desorbable by water, whereas after ∼1 day annealing in aqueous medium the adsorption became too strong to be reversible in water. ‘Strongly’ adsorbed [³H]cellopentaitol was, however, ∼98% desorbed by 6 M NaOH, ∼50% by 0.2 M cellobiose, and ∼30% by 8 M urea, indicating a role for hydrogen-bonding reinforced by complementarity of shape. Gradual adsorption was promoted by kosmotropes (1.4 M Na2SO4 or 30% methanol), and inhibited by chaotropes (8 M urea), supporting a role for hydrogen-bonding. [³H]Cellopentaitol adsorption was strongly competed by non-radioactive cello-oligosaccharides (Cell2–6), the IC50 (half-inhibitory concentration) being highly size-dependent: Cell2, ∼70 mM; Cell3, ∼7 mM; and Cell4–6, ∼0.05 mM. Malto-oligosaccharides (400 mM) had no effect, confirming the role of complementarity. The quantity of adsorbed [³H]cellopentaitol was proportional to mass of cellulose. Of seven cottons tested, wild-type Gossypium arboreum fibres were least capable of adsorbing [³H]cellopentaitol, indicating ensheathment of their microfibrillar surfaces, confirmed by their resistance to cellulase digestion, and potentially attributable to a high glucuronoarabinoxylan content. In conclusion, [³H]cellopentaitol adsorption is a simple, sensitive and quantitative way of titrating ‘naked’ cellulose surfaces. [ABSTRACT FROM AUTHOR]

SUMMARY Alfalfa is one of the most widely cultivated forage crops worldwide. However, soil salinization restricts alfalfa growth and development and affects global productivity. The plant cell wall is the first barrier against various stresses. Therefore, elucidating the alterations in cell wall architecture is crucial for stress adaptation. This study aimed to clarify the impact of myo‐inositol oxygenase 2 (MsMIOX2) on cell wall pectin and hemicellulose biosynthesis under saline–alkali stress and identify the upstream transcription factors that govern MsMIOX2. MsMIOX2 activation induced cell wall pectin and hemicellulose accumulation under saline–alkali stress. The effects of MsMIOX2 in saline–alkali tolerance were investigated by characterizing its overexpression and RNA interference lines. MsMIOX2 overexpression positively regulated the antioxidant system and photosynthesis in alfalfa under saline–alkali stress. MsMIOX2 exhibited myo‐inositol oxygenase activity, which increased polysaccharide contents, facilitated pectin and hemicellulose biosynthesis, and extended the cell wall thickness. However, MsMIOX2 RNA interference decreased cell wall thickness and alleviated alfalfa saline–alkali stress tolerance. In addition, MsbZIP53 was identified as an upstream transcriptional MsMIOX2 regulator by yeast one‐hybrid, electrophoretic mobility shift assay, dual‐luciferase, and beta‐glucuronidase assays. MsbZIP53 overexpression increased MsMIOX2 expression, elevated MIOX activity, reinforced the antioxidant system and photosynthesis, and increased saline–alkali stress tolerance in alfalfa. In conclusion, this study presents a novel perspective for elucidating the molecular mechanisms of saline–alkali stress tolerance in alfalfa and emphasizes the potential use of MsMIOX2 in alfalfa breeding. [ABSTRACT FROM AUTHOR]

This article discusses the evolution and diversity of secondary cell walls (SCWs) in seed plants. The study used cryoSEM to analyze macrofibrils in 33 different angiosperm and gymnosperm species. The results showed that angiosperms generally have narrower macrofibrils compared to gymnosperms, but there are exceptions. The findings provide insights into wood nanostructure and cell wall composition, which can be useful for selecting or engineering desirable wood properties and improving carbon sequestration in plantation forests. The study also examines the evolution of macrofibril size in seed plants, specifically focusing on angiosperms and gymnosperms. The researchers found that large macrofibrils are characteristic of gymnosperms, while small macrofibrils are characteristic of angiosperms. However, they also discovered an intermediate macrofibril size in the Liriodendron genus. The researchers speculate that this may be due to differences in cell wall composition or environmental factors. Further research is needed to investigate these factors and their impact on carbon sequestration and storage by plants. [Extracted from the article]

This paper introduces an enzymatic approach to estimate internal mass-transfer resistances during food digestion studies. Cellulase has been used to degrade starch cell walls (where cellulose is a significant component) and reduce the internal mass-transfer resistance, so that the starch granules are released and hydrolysed by amylase, increasing the starch hydrolysis rates, as a technique for measuring the internal mass-transfer resistance of cell walls. The estimated internal mass-transfer resistances for granular starch hydrolysis in a beaker and stirrer system for simulating the food digestion range from 2.2 × 107 m−1 s at a stirrer speed of 100 rpm to 6.6 × 107 m−1 s at 200 rpm. The reaction rate constants for cellulase-treated starch are about three to eight times as great as those for starch powder. The beaker and stirrer system provides an in vitro model to quantitatively understand external mass-transfer resistance and compare mass-transfer and reaction rate kinetics in starch hydrolysis during food digestion. Particle size analysis indicates that starch cell wall degradation reduces starch granule adhesion (compared with soaked starch samples), though the primary particle sizes are similar, and increases the interfacial surface area, reducing internal mass-transfer resistance and overall mass-transfer resistance. Dimensional analysis (such as the Damköhler numbers, Da, 0.3–0.5) from this in vitro system shows that mass-transfer rates are greater than reaction rates. At the same time, SEM (scanning electron microscopy) images of starch particles indicate significant morphology changes due to the cell wall degradation. [ABSTRACT FROM AUTHOR]

SUMMARY Hydathodes are small organs found on the leaf margins of vascular plants which release excess xylem sap through a process called guttation. While previous studies have hinted at additional functions of hydathode in metabolite transport or auxin metabolism, experimental support is limited. We conducted comprehensive transcriptomic, metabolomic and physiological analyses of mature Arabidopsis hydathodes. This study identified 1460 genes differentially expressed in hydathodes compared to leaf blades, indicating higher expression of most genes associated with auxin metabolism, metabolite transport, stress response, DNA, RNA or microRNA processes, plant cell wall dynamics and wax metabolism. Notably, we observed differential expression of genes encoding auxin‐related transcriptional regulators, biosynthetic processes, transport and vacuolar storage supported by the measured accumulation of free and conjugated auxin in hydathodes. We also showed that 78% of the total content of 52 xylem metabolites was removed from guttation fluid at hydathodes. We demonstrate that NRT2.1 and PHT1;4 transporters capture nitrate and inorganic phosphate in guttation fluid, respectively, thus limiting the loss of nutrients during this process. Our transcriptomic and metabolomic analyses unveil an organ with its specific physiological and biological identity. [ABSTRACT FROM AUTHOR]

Lignin, a major plant cell wall component, has an important role in plant-defense mechanisms against pathogens and is a promising renewable carbon source to produce bio-based chemicals. However, our understanding of microbial metabolism is incomplete regarding certain lignin-related compounds like p-coumaryl and sinapyl alcohols. Here, we reveal peripheral pathways for the catabolism of the three main lignin precursors (p-coumaryl, coniferyl, and sinapyl alcohols) in the plant pathogen Xanthomonas citri. Our study demonstrates all the necessary enzymatic steps for funneling these monolignols into the tricarboxylic acid cycle, concurrently uncovering aryl aldehyde reductases that likely protect the pathogen from aldehydes toxicity. It also shows that lignin-related aromatic compounds activate transcriptional responses related to chemotaxis and flagellar-dependent motility, which might play an important role during plant infection. Together our findings provide foundational knowledge to support biotechnological advances for both plant diseases treatments and conversion of lignin-derived compounds into bio-based chemicals. Plants strengthen their cell walls with lignin to prevent pathogen colonization. Here, Martim et al show how Xanthomonas citri degrades lignin precursors and detoxifies lignin-derived molecules to overcome this plant defense. [ABSTRACT FROM AUTHOR]

Lignin is the main component of plant cell walls, conferring upon lignocellulosic biomass both excellent mechanical and barrier properties. At the same time, the considerable number of unsaturated groups and conjugated structures present in lignin render it a promising candidate for applications in the optical domain. In recent years, the development of the optical properties of lignin and lignin-derived optical materials has paved the way for a novel avenue of lignin valorization. This review is concerned with the mechanisms of lignin-derived optical materials, with particular emphasis on the physical and chemical structures that are linked to their optical performance, including UV absorption, photothermal conversion, and photoluminescence. Additionally, the potential applications of these materials in energy storage, bioimaging, structural materials, and photonic crystal are also presented, demonstrating the unique optical properties of lignin. Finally, the challenges and future directions of lignin as an optical material are presented, with the objective of developing lignin into a polymer biobased raw material that can serve advanced emerging industries. [ABSTRACT FROM AUTHOR]

Background: The postharvest rot of kiwifruit is one of the most devastating diseases affecting kiwifruit quality worldwide. However, the genomic basis and pathogenicity mechanisms of kiwifruit rot pathogens are lacking. Here we report the first whole genome sequence of Pestalotiopsis microspora, one of the main pathogens causing postharvest kiwifruit rot in China. The genome of strain KFRD-2 was sequenced, de novo assembled, and analyzed. Results: The genome of KFRD-2 was estimated to be approximately 50.31 Mb in size, with an overall GC content of 50.25%. Among 14,711 predicted genes, 14,423 (98.04%) exhibited significant matches to genes in the NCBI nr database. A phylogenetic analysis of 26 known pathogenic fungi, including P. microspora KFRD-2, based on conserved orthologous genes, revealed that KFRD-2's closest evolutionary relationships were to Neopestalotiopsis spp. Among KFRD-2's coding genes, 870 putative CAZy genes spanned six classes of CAZys, which play roles in degrading plant cell walls. Out of the 25 other plant pathogenic fungi, P. microspora possessed a greater number of CAZy genes than 22 and was especially enriched in GH and AA genes. A total of 845 transcription factors and 86 secondary metabolism gene clusters were predicted, representing various types. Furthermore, 28 effectors and 109 virulence-enhanced factors were identified using the PHI (pathogen host-interacting) database. Conclusion: This complete genome sequence analysis of the kiwifruit postharvest rot pathogen P. microspora enriches our understanding its disease pathogenesis and virulence. This study establishes a theoretical foundation for future investigations into the pathogenic mechanisms of P. microspora and the development of enhanced strategies for the efficient management of kiwifruit postharvest rots. [ABSTRACT FROM AUTHOR]

Background: Dissection of complex plant cell wall structures demands a sensitive and quantitative method. FTIR is used regularly as a screening method to identify specific linkages in cell walls. However, quantification and assigning spectral bands to particular cell wall components is still a major challenge, specifically in crop species. In this study, we addressed these challenges using ATR-FTIR spectroscopy as it is a high throughput, cost-effective and non-destructive approach to understand the plant cell wall composition. This method was validated by analysing different varieties of mungbean which is one of the most important legume crops grown widely in Asia. Results: Using standards and extraction of a specific component of cell wall components, we assigned 1050–1060 cm−1 and 1390–1420 cm−1 wavenumbers that can be widely used to quantify cellulose and lignin, respectively, in Arabidopsis, Populus, rice and mungbean. Also, using KBr as a diluent, we established a method that can relatively quantify the cellulose and lignin composition among different tissue types of the above species. We further used this method to quantify cellulose and lignin in field-grown mungbean genotypes. The ATR-FTIR-based study revealed the cellulose content variation ranges from 27.9% to 52.3%, and the lignin content variation ranges from 13.7% to 31.6% in mungbean genotypes. Conclusion: Multivariate analysis of FT-IR data revealed differences in total cell wall (600–2000 cm−1), cellulose (1000–1100 cm−1) and lignin (1390–1420 cm−1) among leaf and stem of four plant species. Overall, our data suggested that ATR-FTIR can be used for the relative quantification of lignin and cellulose in different plant species. This method was successfully applied for rapid screening of cell wall composition in mungbean stem, and similarly, it can be used for screening other crops or tree species. [ABSTRACT FROM AUTHOR]

Summary Lignin, a complex heterogenous polymer present in virtually all plant cell walls, plays a critical role in protecting plants from various stresses. However, little is known about how lignin modifications in sorghum will impact plant defense against sugarcane aphids (SCA), a key pest of sorghum. We utilized the sorghum brown midrib (bmr) mutants, which are impaired in monolignol synthesis, to understand sorghum defense mechanisms against SCA. We found that loss of Bmr12 function and overexpression (OE) of Bmr12 provided enhanced resistance and susceptibility to SCA, respectively, as compared with wild‐type (WT; RTx430) plants. Monitoring of the aphid feeding behavior indicated that SCA spent more time in reaching the first sieve element phase on bmr12 plants compared with RTx430 and Bmr12‐OE plants. A combination of transcriptomic and metabolomic analyses revealed that bmr12 plants displayed altered auxin metabolism upon SCA infestation and specifically, elevated levels of auxin conjugate indole‐3‐acetic acid–aspartic acid (IAA–Asp) were observed in bmr12 plants compared with RTx430 and Bmr12‐OE plants. Furthermore, exogenous application of IAA–Asp restored resistance in Bmr12‐OE plants, and artificial diet aphid feeding trial bioassays revealed that IAA–Asp is associated with enhanced resistance to SCA. Our findings highlight the molecular underpinnings that contribute to sorghum bmr12‐mediated resistance to SCA. [ABSTRACT FROM AUTHOR]

Although many of the structures and organelles of vegetative cells are comparable to those of animal tissues, significant differences between the two kingdoms require modifications in histological techniques for both tissue processing steps and histochemical staining techniques. The authors investigated the challenges of working with plant tissues by collecting various flora to represent the four main plant organs: leaf, stem, root, and flower/fruit. Triplicate samples for each specimen were placed into formalin for paraffin embedding, placed into formalin for later frozen sections, and used fresh to undergo immediate frozen sectioning. Frozen sections of plant tissues were more difficult to obtain than formalin-fixed paraffin-embedded (FFPE) sections, exhibited tissue loss during staining, and were inferior morphologically to FFPE sections. Although, historically, plant tissue fixation and processing has employed several different reagents compared with those used in animal tissue processing and took significantly longer times, the current investigation determined reagents and protocols from a modern histology laboratory which processes mammalian tissues can be applied to plant tissue processing with only slight modifications in respect to reagent timing. Additionally, staining techniques were compared and while it is well known that plant cell walls stain well with safranin O, the current investigation determined the uptake of safranin O can be accelerated by incubating at 60°C. [ABSTRACT FROM AUTHOR]

Introduction: As an essential part of plant cell walls, lignin provides mechanical support for plant growth, enhances water transport, and helps to defend against pathogens. As the most abundant natural aromatic-based renewable resource on earth, its biosynthesis has always been a research focus, and it is still currently under study. Methods: In this study, the p-coumaryl alcohol analog (HALK) and the coniferyl alcohol analog (GALK) containing an alkyne group at the ortho position were synthesized and applied to lignification in vivo and in vitro. The incorporation of these novel lignin monomers was observed via fluorescence imaging. Results and Discussion: It was found that the two monolignol analogs could be incorporated in dehydrogenated polymers (DHPs) in vitro and in flax cell walls in vivo. The results showed that as the cultivation time and precursor concentration varied, the deposition of H and G-type lignin exhibited differences in deposition mode. At the subcellular scale, the deposited lignin first appears in the cell corner and the middle lamella, and then gradually appears on the cell walls. Furthermore, lignin was also found in bast fiber. It was demonstrated that these new molecules could provide high-resolution localization of lignin during polymerization. [ABSTRACT FROM AUTHOR]

The cell wall shapes plant cell morphogenesis and affects the plasticity of organ growth. However, the way in which cell wall establishment is regulated by ethylene remains largely elusive. Here, by analyzing cell wall patterns, cell wall composition and gene expression in rice (Oryza sativa, L.) roots, we found that ethylene induces cell wall thickening and the expression of cell wall synthesis-related genes, including CELLULOSE SYNTHASE-LIKE C1, 2, 7, 9, 10 (OsCSLC1, 2, 7, 9, 10) and CELLULOSE SYNTHASE A3, 4, 7, 9 (OsCESA3, 4, 7, 9). Overexpression and mutant analyses revealed that OsCSLC2 and its homologs function in ethylene-mediated induction of xyloglucan biosynthesis mainly in the cell wall of root epidermal cells. Moreover, OsCESA-catalyzed cellulose deposition in the cell wall was enhanced by ethylene. OsCSLC-mediated xyloglucan biosynthesis likely plays an important role in restricting cell wall extension and cell elongation during the ethylene response in rice roots. Genetically, OsCSLC2 acts downstream of ETHYLENE-INSENSITIVE3-LIKE1 (OsEIL1)-mediated ethylene signaling, and OsCSLC1, 2, 7, 9 are directly activated by OsEIL1. Furthermore, the auxin signaling pathway is synergistically involved in these regulatory processes. These findings link plant hormone signaling with cell wall establishment, broadening our understanding of root growth plasticity in rice and other crops. Ethylene promotes CELLULOSE SYNTHASE-LIKE C protein-mediated xyloglucan synthesis in epidermal cell walls in an ETHYLENE-INSENSITIVE3-LIKE1-dependent manner for root growth inhibition in rice. [ABSTRACT FROM AUTHOR]

Members of the domain of unknown function 231/trichome birefringence–like (TBL) family have been shown to be O -acetyltransferases catalyzing the acetylation of plant cell wall polysaccharides, including pectins, mannan, xyloglucan and xylan. However, little is known about the origin and evolution of plant cell wall polysaccharide acetyltransferases. Here, we investigated the biochemical functions of TBL homologs from Klebsormidium nitens , a representative of an early divergent class of charophyte green algae that are considered to be the closest living relatives of land plants, and Marchantia polymorpha , a liverwort that is an extant representative of an ancient lineage of land plants. The genomes of K. nitens and Marchantia polymorpha harbor two and six TBL homologs, respectively. Biochemical characterization of their recombinant proteins expressed in human embryonic kidney 293 cells demonstrated that the two K. nitens TBLs exhibited acetyltransferase activities acetylating the pectin homogalacturonan (HG) and hence were named KnPOAT1 and KnPOAT2. Among the six M. polymorpha TBLs, five (MpPOAT1 to 5) possessed acetyltransferase activities toward pectins and the remaining one (MpMOAT1) catalyzed 2- O - and 3- O -acetylation of mannan. While MpPOAT1,2 specifically acetylated HG, MpPOAT3,4,5 could acetylate both HG and rhamnogalacturonan-I. Consistent with the acetyltransferase activities of these TBLs, pectins isolated from K. nitens and both pectins and mannan from M. polymorpha were shown to be acetylated. These findings indicate that the TBL genes were recruited as cell wall polysaccharide O -acetyltransferases as early as in charophyte green algae with activities toward pectins and they underwent expansion and functional diversification to acetylate various cell wall polysaccharides during evolution of land plants. [ABSTRACT FROM AUTHOR]

Malbranchea is a genus within the order Onygenales (phylum Ascomycota) that includes predominantly saprobic cosmopolitan species. Despite its ability to produce diverse secondary metabolites, no genomic data for Malbranchea spp. are currently available in databases. Therefore, in this study, we obtained, assembled, and annotated the genomic sequence of the ex-type strain of Malbranchea zuffiana (CBS 219.58). For the genomic sequencing, we employed both the Illumina and PacBio platforms, followed by hybrid assembly using MaSuRCA. Quality assessment of the assembly was performed using QUAST and BUSCO tools. Annotation was conducted using BRAKER2, and functional annotation was completed with InterProScan. The resulting genome was of high quality, with a size of 26.46 Mbp distributed across 38 contigs and a BUSCO completion rate of 95.7%, indicating excellent contiguity and assembly completeness. A total of 8248 protein-encoding genes were predicted, with functional annotations assigned to 73.9% of them. Moreover, 82 genes displayed homology with entries in the Pathogen Host Interactions (PHI) database, while 494 genes exhibited similarity to entries in the Carbohydrate-Active Enzymes (CAZymes) database. Furthermore, 30 biosynthetic gene clusters (BGCs) were identified, suggesting significant potential for the biosynthesis of diverse secondary metabolites. Comparative functional analysis with closely related species unveiled a considerable abundance of domains linked to enzymes involved in keratin degradation, alongside a restricted number of domains associated with enzymes engaged in plant cell wall degradation in all studied species of the Onygenales. This genome-based elucidation not only enhances our comprehension of the biological characteristics of M. zuffiana but also furnishes valuable insights for subsequent investigations concerning Malbranchea species and the order Onygenales. [ABSTRACT FROM AUTHOR]

Leaves play a crucial role as ornamental organs in Spathiphyllum, exhibiting distinct differences across various Spathiphyllum varieties. Leaf development is intricately linked to processes of cell proliferation and expansion, with cell morphology often regulated by plant cell walls, primarily composed of cellulose. Alterations in cellulose content can impact cell morphology, subsequently influencing the overall shape of plant organs. Although cellulases have been shown to affect cellulose levels in plant cells, genetic evidence linking them to the regulation of leaf shape remains limited. This study took the leaves of Spathiphyllum 'Mojo' and its somatic variants as the research objects. We screened four cellulase gene family members from the transcriptome and then measured the leaf cellulose content, cellulase activity, and expression levels of cellulase-related genes. Correlation analysis pinpointed the gene SpGH9A3 as closely associated with leaf shape variations in the mutant. Green fluorescent fusion protein assays revealed that the SpGH9A3 protein was localized to the cell membrane. Notably, the expression of the SpGH9A3 gene in mutant leaves peaked during the early spread stage, resulting in smaller overall leaf size and reduced cellulose content upon overexpression in Arabidopsis. [ABSTRACT FROM AUTHOR]

Flax (Linum usitatissimum L.) is an important crop plant with pharmaceutical significance. It is described in pharmacopoeias (the United States Pharmacopeia and the European Pharmacopoeia), which confirms that it (especially the seeds) is a valuable medicinal product. Similar to flax seeds, which accumulate bioactive compounds, flax in vitro cultures are also a rich source of flavonoids, phenolics, lignans and neolignans. In the present study, flax suspension cultures after treatment of the non-pathogenic Fusarium oxysporum strain Fo47 were established and analyzed. The study examined the suitability of Fo47 as an elicitor in flax suspension cultures and provided interesting data on the impact of these endophytic fungi on plant metabolism and physiology. Two flax cultivars (Bukoz and Nike) and two compositions of media for flax callus liquid cultures were tested. Biochemical analysis revealed enhanced levels of secondary metabolites (total flavonoid and total phenolic content) and photosynthetically active pigments in the flax callus cultures after treatment with the non-pathogenic fungal strain F. oxysporum Fo47 when compared to control, untreated cultures. In cultures with the selected, optimized conditions, FTIR analysis was performed and revealed changes in the structural properties of cell wall polymers after elicitation of cultures with F. oxysporum Fo47. The plant cell wall polymers were more strongly bound, and the crystallinity index (Icr) of cellulose was higher than in control, untreated samples. However, lignin and pectin levels were lower in the flax callus liquid cultures treated with the non-pathogenic strain of Fusarium when compared to the untreated control. The potential application of the non-pathogenic strain of F. oxysporum for enhancing the synthesis of desired secondary metabolites in plant tissue cultures is discussed. [ABSTRACT FROM AUTHOR]

Agricultural mulching is an important input for modern agricultural production and plays an important role in guaranteeing food security worldwide. At present, polyethylene (PE) mulching is still commonly used in agricultural production in most countries around the world, which is non-biodegradable, and years of mulching have caused serious agricultural white pollution. Lignin is one of the three major components of plant cell walls, and it is also the main renewable natural aromatic compounds in nature. Lignin-based composite film materials are green, biodegradable, and show good prospects for development in the field of agricultural mulch. This paper introduces the types, structure, and application status of lignin, summarizes the preparation of lignin-based composite film materials and its latest research progress, focuses on the types, preparation methods, and application examples of lignin-based agricultural mulching, and looks forward to the future development prospects of lignin-based agricultural mulching. [ABSTRACT FROM AUTHOR]

Rosalia funebris (RFUNE; Cerambycidae), the banded alder borer, is a longhorn beetle whose larvae feed on the wood of various economically and ecologically significant trees in western North America. Adults are short-lived and not known to consume plant material substantially. We sequenced, assembled, and annotated the RFUNE genome using HiFi and RNASeq data. We documented genome architecture and gene content, focusing on genes putatively involved in plant feeding (phytophagy). Comparisons were made to the well-studied genome of the Asian longhorned beetle (AGLAB; Anoplophora glabripennis) and other Cerambycidae. The 814 Mb RFUNE genome assembly was distributed across 42 contigs, with an N50 of 30.18 Mb. Repetitive sequences comprised 60.27% of the genome, and 99.0% of expected single-copy orthologous genes were fully assembled. We identified 12,657 genes, fewer than in the four other species studied, and 46.4% fewer than for Aromia moschata (same subfamily as RFUNE). Of the 7,258 orthogroups shared between RFUNE and AGLAB, 1,461 had more copies in AGLAB and 1,023 had more copies in RFUNE. We identified 240 genes in RFUNE that putatively arose via horizontal transfer events. The RFUNE genome encoded substantially fewer putative plant cell wall degrading enzymes than AGLAB, which may relate to the longer-lived plant-feeding adults of the latter species. The RFUNE genome provides new insights into cerambycid genome architecture and gene content and provides a new vantage point from which to study the evolution and genomic basis of phytophagy in beetles. [ABSTRACT FROM AUTHOR]

Xyloglucan in plant cell walls has complex side-chain structures; Aspergillus oryzae produces various enzymes to degrade and assimilate xyloglucan. In this study, we identified and characterized α-1,2- l -fucosidase (AfcA) which is involved in xyloglucan degradation in A. oryzae. AfcA expression was induced in the presence of xyloglucan oligosaccharides. AfcA showed specific activity toward α-(1→2)-linked l -fucopyranosyl residues attached to the side chains of xyloglucan oligosaccharides and milk oligosaccharides, but not toward α-(1→3)-, α-(1→4)-, and α-(1→6)-linked l -fucopyranosyl residues. As fucopyranosyl residues in the side chains of xyloglucan oligosaccharides prevent the degradation of xyloglucan oligosaccharides by isoprimeverose-producing oligoxyloglucan hydrolase and β-galactosidase, the cooperative action of AfcA, isoprimeverose-producing oligoxyloglucan hydrolase, and β-galactosidase play a key role in degrading fucosylated xyloglucan in A. oryzae. [ABSTRACT FROM AUTHOR]

Wheat plants infested by Russian wheat aphids (RWA) induce a cascade of defence responses, which include increased activity of β-1,3-glucanase and peroxidase (POD). There is a lack of information regarding β-1,3-glucanase and POD synergistic effects on the plant cell wall modification and characterisation during wheat-RWA infestation. This study aimed to characterise the physicochemical properties of the cell wall-bound POD and β-1,3-glucanase during RWA-wheat interaction. The susceptible Tugela, moderately resistant Tugela-Dn1, and resistant Tugela-Dn5 cultivars were planted in a glasshouse to a seedling stage before being infested with RWASA2 for 14 days. The findings showed a significant increase in β-1,3-glucanase and POD activities in the infested Tugela-Dn5 and Tugela-Dn1 cultivars over the 14 days. However, in the Tugela enzymes were repressed. In addition, it was shown for the first time that β-1,3 − 1,4-glucanase activity specific toward mixed-linked glucan was significant in the resistant cultivar over 14 days. β-1,3-glucanase, β-1,3 − 1,4-glucanase and POD displayed optimum at pH 5. β-1,3-glucanase and POD displayed temperature optimum at 40 and 50 °C, respectively. However, β-1,3 − 1,4-glucanase had temperature optimum at 25 °C. β-1,3-glucanase and POD had a thermo-stability at 37 °C followed by about 80% relative activity at 70 °C, but β-1,3 − 1,4-glucanase displayed thermostability at 25 °C and retained more than 75% at 70 °C, confirming that β-1,3 − 1,4-glucanase and β-1,3-glucanase induced in the resistant cultivars cell wall were two different enzymes. Mechanism of actions and oligosaccharide displayed that β-1,3-glucanase was highly active against β-1,3-glucan and required a triose and higher oligosaccharide to be active. Our findings demonstrated cell-wall bound POD and β-1,3-glucanase activities significantly increased in wheat after RWASA2 infestation, revealing they acted synergistically to reinforce the cell wall to deter RWASA2 feeding in resistant cultivars. [ABSTRACT FROM AUTHOR]

Bacteria within the Paenibacillus genus are known to secrete a diverse array of enzymes capable of breaking down plant cell wall polysaccharides. We studied the extracellular xylanolytic activity of Paenibacillus xylanivorans and examined the complete range of secreted proteins when grown on carbohydrate-based carbon sources of increasing complexity, including wheat bran, sugar cane straw, beechwood xylan and sucrose, as control. Our data showed that the relative abundances of secreted proteins varied depending on the carbon source used. Extracellular enzymatic extracts from wheat bran (WB) or sugar cane straw (SCR) cultures had the highest xylanolytic activity, coincidently with the largest representation of carbohydrate active enzymes (CAZymes). Scaling-up to a benchtop bioreactor using WB resulted in a significant enhancement in productivity and in the overall volumetric extracellular xylanase activity, that was further concentrated by freeze-drying. The enzymatic extract was efficient in the deconstruction of xylans from different sources as well as sugar cane straw pretreated by alkali extrusion (SCRe), resulting in xylobiose and xylose, as primary products. The overall yield of xylose released from SCRe was improved by supplementing the enzymatic extract with a recombinant GH43 β-xylosidase (EcXyl43) and a GH62 α-l-arabinofuranosidase (CsAbf62A), two activities that were under-represented. Overall, we showed that the extracellular enzymatic extract from P. xylanivorans, supplemented with specific enzymatic activities, is an effective approach for targeting xylan within lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

This article from Veterinary Pathology provides images and descriptions of various pulmonary diseases in animals. It includes images and information on diseases such as bovine tuberculosis, bronchial cartilage hypoplasia, subpleural macrophage foci, pulmonary endometriosis, and enzootic calcinosis. The article aims to educate readers about these diseases and their characteristics. [Extracted from the article]