Ameliorative potential of ethanol extract of Calyptrochilum emarginatum leaves on scopolamine-induced amnesia in male swiss mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Calyptrochilum emarginatum (Afzel. Ex Sw.) Schltr. (Orchidaceae) is a traditional medicinal plant known for its antimicrobial properties and efficacy in managing convulsive fever and menstrual disorders and addressing conditions such as malaria, tuberculosis, and cough. AIM OF THE STUDY: The study aims to examine the memory-enhancing and neuroprotective properties of ethanol extract of Calyptrochilum emarginatum leaves (EECEL) in scopolamine-induced amnesia mice model. MATERIALS AND METHODS: Forty-two male mice were divided into six groups (n = 7). Group 1 served as control, administered distilled water (10 mL/kg, p. o), group 2 received scopolamine only (3 mg/kg, i. p.), groups 3 to 6 received pretreatments of EECEL (50, 100, and 200 mg/kg, p. o.) and donepezil (1 mg/kg, p. o.) 30 min before scopolamine (3 mg/kg), for seven days. Following treatments, behavioral (learning and memory) assessments were carried out, while biochemical (acetylcholinesterase activity, oxidative stress markers, inflammatory cytokines markers) and histological evaluations were done after euthanasia. RESULTS: Scopolamine significantly impaired spatial, long term and recognition memory. Nevertheless, administration of EECEL (50, 100, and 200 mg/kg orally) enhanced memory function in mice, as observed in the Y maze [F (5, 30) = 20.23, p < 0.0001], Morris water maze [F (10, 90) = 3.105, p = 0.0019; [F (5, 30) = 21.13, p < 0.0001]], and novel object recognition tasks [F (5, 30) = 37.22, p < 0.0001)]. Scopolamine-treated mice exhibited significant dysfunction in the cholinergic system, as evidenced by elevated AChE activity [0.099 ± 0.005 vs. 0.063 ± 0.004 mol/min/g] with an elevation in oxidative stress. On the other hand, administration of EECEL counteracted these consequences by reducing AChE activity, mitigating oxidative damage, reducing pro-inflammatory cytokines, and preventing degeneration of neurons. CONCLUSION: The results demonstrated that EECEL effectively mitigates scopolamine-induced memory impairment via an oxido-inflammatory mechanism and modulation of the central cholinergic system.

Isolation and characterisation of sesquiterpene synthase from aromatic orchid Phalaenopsis bellina (Rchb.f.) Christenson.

BACKGROUND: Phalaenopsis bellina, an orchid native to Borneo, is renowned for its unique appearance. It releases distinct fragrances, which have been linked to the presence of terpenoids. However, the identification and study of sesquiterpene synthase in P. bellina remain limited. In this study, we examines the functional characterisation of terpene synthase (TPS) from P. bellina, known as PbTS, through recombinant protein expression and its manifestation in the flower. METHODS AND RESULTS: Gene annotation of PbTS revealed that the inferred peptide sequence of PbTS comprises 1,680 bp nucleotides encoding 559 amino acids with an estimated molecular mass of 65.2 kDa and a pI value of 5.4. A similarity search against GenBank showed that PbTS shares similarities with the previously published partial sequence of P. bellina (ABW98504.1) and Phalaenopsis equestris (XP_020597359.1 and ABW98503.1). Intriguingly, the phylogenetic analysis places the PbTS gene within the TPS-a group. In silico analysis of PbTS demonstrated stable interactions with farnesyl pyrophosphate (FPP), geranyl pyrophosphate (GPP), and geranylgeranyl pyrophosphate (GGPP). To verify this activity, an in vitro enzyme assay was performed on the PbTS recombinant protein, which successfully converted FPP, GPP, and GGPP into acyclic sesquiterpene ß-farnesene, yielding approximately 0.03 mg/L. Expressional analysis revealed that the PbTS transcript was highly expressed in P. bellina, but its level did not correlate with ß-farnesene levels across various flowering time points and stages. CONCLUSION: The insights gained from this study will enhance the understanding of terpenoid production in P. bellina and aid in the discovery of novel fragrance-related genes in other orchid species.

Complete chloroplast genome of a montane plant Spathoglottis aurea Lindl.: Comparative analyses and phylogenetic relationships among members of tribe collabieae.

The yellow-flowered Spathoglottis aurea (tribe Collabieae; family Orchidaceae) is native to the mountainous areas of Peninsular Malaysia. The species is well known as an ornamental plant and for its role in artificial hybrid breeding. There is an interesting evolutionary relationship between S. aurea and the geographically isolated S. microchilina from Borneo that has encouraged further study of the S. aurea populations, but the genomic resource for S. aurea has not yet been reported. The present study reports the first work to characterize a chloroplast (cp) genome among the Spathoglottis genus. The complete cp genome of S. aurea was assembled from a sequence generated by the Illumina platform and analysed in comparison with other Collabieae species available in the GenBank database. The cp genome of S. aurea is 157,957 base pairs (bp) in length with guanine-cytosine (GC) content of 37.3%. The genome possessed a typical quadripartite cp genome structure with large single-copy (LSC) (86,888 bp), small single-copy (SSC) (18,125 bp) and inverted repeat (IR) (26,472 bp) sequences. A total of 134 genes were annotated, with 88 protein coding genes (PCGs), 38 transfer RNA (tRNA) genes and eight ribosomal RNA (rRNA) genes. Overall, 80 simple sequence repeats (SSR) or microsatellites were identified. Comparative analysis with other Collabieae species revealed high conservation in the cp genome arrangements with minimal difference in genome lengths. However, several mutational hotspots were also detected, with high potential to be developed as genetic markers for phylogenetic analysis. Characterization of the S. aurea cp genome revealed its conserved nature without gene loss or rearrangements when compared to other species of the Collabieae tribe. Phylogenetic analysis of Collabieae species also revealed that S. aurea has a distant evolutionary relationship to other members of the Collabieae species, despite the presence of problematic genera such as Phaius and Cephalantheropsis.

Sobralia decora Bateman (Orchidaceae) and its relatives in South America.

A taxonomical study of Sobralia decora and allied species recorded in South America is presented. The group is characterized by light pink to purple flowers, often with a white tip of the labellum and yellow to brown area on its throat. If considering the habit, the species can be recognized and distinguished from all other Sobralia species by producing keikis-stems arising from the old inflorescence. The similarity of the species forming the discussed complex caused numerous mistakes noticed in the literature and among the herbarium specimens. The aim of the elaboration is to clarify the differences allowing to determine the living and herbarium specimens with no errors.

Genome-wide identification, expression pattern and interacting protein analysis of INDETERMINATE DOMAIN (IDD) gene family in Phalaenopsis equestris.

The plant-specific INDETERMINATE DOMAIN (IDD) gene family is important for plant growth and development. However, a comprehensive analysis of the IDD family in orchids is limited. Based on the genome data of Phalaenopsis equestris, the IDD gene family was identified and analyzed by bioinformatics methods in this study. Ten putative P. equestris IDD genes (PeIDDs) were characterized and phylogenetically classified into two groups according to their full amino acid sequences. Protein motifs analysis revealed that overall structures of PeIDDs in the same group were relatively conserved. Its promoter regions harbored a large number of responsive elements, including light responsive, abiotic stress responsive elements, and plant hormone cis-acting elements. The transcript level of PeIDD genes under cold and drought conditions, and by exogenous auxin (NAA) and abscisic acid (ABA) treatments further confirmed that most PeIDDs responded to various conditions and might play essential roles under abiotic stresses and hormone responses. In addition, distinct expression profiles in different tissues/organs suggested that PeIDDs might be involved in various development processes. Furthermore, the prediction of protein-protein interactions (PPIs) revealed some PeIDDs (PeIDD3 or PeIDD5) might function via cooperating with chromatin remodeling factors. The results of this study provided a reference for further understanding the function of PeIDDs.

In silico analysis of Apostasia wallichii (Apostasioideae) and Ludisia discolor (Orchidoideae) orchids reveals different repeats composition despite the same genome size.

Repetitive sequences can lead to variation in DNA quantity and composition among species. The Orchidaceae, the largest angiosperm family, is divided into five subfamilies, with Apostasioideae as the basal group and Orchidoideae and Epidendroideae showing high diversification rates. Despite their different evolutionary paths, some species in these groups have similar nuclear DNA content. This study focuses on one example to understand the dynamics of major repetitive DNAs in the nucleus. We used Next-Generation Sequencing (NGS) data from Apostasia wallichii (Apostasioideae) and Ludisia discolor (Orchidoideae) to identify and quantify the most abundant repeats. The repetitive fraction varied in abundance (27.5% in L. discolor and 60.6% in A. wallichii) and composition, with LTR retrotransposons of different lineages being the most abundant repeats in each species. Satellite DNAs showed varying organization and abundance. Despite the unbalanced ratio between single-copy and repetitive DNA sequences, the two species had the same genome size, possibly due to the elimination of non-essential genes. This phenomenon has been observed in other Apostasia and likely led to the proliferation of transposable elements in A. wallichii. Deep genome information in the future will aid in understanding the contraction/expansion of gene families and the evolution of sequences in these genomes.

Bioactivity-Guided Isolation of Antistroke Compounds from Gymnadenia conopsea (L.) R. Br.

A bioactivity-guided separation strategy was used to identify novel antistroke compounds from Gymnadenia conopsea (L.) R. Br., a medicinal plant. As a result, 4 undescribed compounds (1-2, 13, and 17) and 13 known compounds, including 1 new natural product (3), were isolated from G. conopsea. The structures of these compounds were elucidated through comprehensive spectroscopic techniques, such as 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS), and quantum chemical calculations. An oxygen-glucose deprivation/reoxygenation (OGD/R)-injured rat pheochromocytoma (PC12) cell model was used to evaluate the antistroke effects of the isolates. Compounds 1-2, 10-11, 13-15, and 17 provided varying degrees of protection against OGD/R injury in the PC12 cells at concentrations of 12.5, 25, and 50 µM. Among the tested compounds, compound 17 demonstrated the most potent neuroprotective effect, which was equivalent to that of the positive control drug (edaravone). Then, transcriptomic and bioinformatics analyses were conducted to reveal the regulatory effect of compound 17 on gene expression. In addition, quantitative real-time PCR (qPCR) was performed to verify the results of the transcriptomic and bioinformatics analyses. These results suggest that the in vitro antistroke effect of compound 17 may be associated with the regulation of the Col27a1 gene. Thus, compound 17 is a promising candidate for the development of novel antistroke drugs derived from natural products, and this topic should be further studied.

Self-assembled ROS-triggered Bletilla striata polysaccharide-releasing hydrogel dressing for inflammation-regulation and enhanced tissue-healing.

The antimicrobial and pro-healing properties remain critical clinical objectives for skin wound management. However, the escalating problem of antibiotic overuse and the corresponding rise in bacterial resistance necessitates an urgent shift towards an antibiotic-free approach to antibacterial treatment. The quest for antimicrobial efficacy while accelerating wound healing without antibiotic treatment have emerged as innovative strategies in skin wound treatment. Here, a dual-function hydrogel with antimicrobial and enhanced tissue-healing properties was developed by utilizing cyclodextrin, ferrocene, polyethyleneimine (PEI), and Bletilla striata polysaccharide (BSP), through multiple non-covalent interactions, which can intelligently release BSP by recognizing the wound inflammatory microenvironment through the cyclodextrin-ferrocene unit. Moreover, the porosity (65 % - 85 %), Young's modulus (400 KPa - 140 KPa), and DPPH scavenge rate (18 % - 40 %) of the hydrogel are modulated by varying the BSP content. The hydrogel exhibits outstanding antibacterial properties (98.3 % reduction of Escherichia coli observed after exposure to HTFC@BSP-20 for 24 h) and favorable biocompatibility. Furthermore, in a rat full-thickness skin wound model, the dual-function hydrogel significantly accelerates wound healing, increased CD31 expression promotes vascular regeneration, reduced TNF-α express and inhibited the inflammation. This multifunctional ROS responsive hydrogel provides a new perspective for antibiotics-free treatment of skin injuries.

Plastome Evolution and Comparative Analyses of a Recently Radiated Genus Vanda (Aeridinae, Orchidaceae).

Vanda R.Br. is an epiphytic orchid genus with significant horticultural and ornamental value. Previous molecular studies expanded Vanda including some members from five other genera. However, the interspecific relationships of this recently radiated genus have remained unclear based on several DNA markers until now. In this study, the complete plastome has been used to infer the phylogenetic relationships of Vanda s.l. The five newly obtained plastomes ranged from 146,340 bp to 149,273 bp in length, with a GC content ranging from 36.5% to 36.7%. The five plastomes contained 74 protein-coding genes (CDSs), 38 tRNAs, and 8 rRNAs, and their ndh genes underwent loss or pseudogenization. Comparative plastome analyses of 13 Vanda species revealed high conservation in terms of genome size, structure, and gene order, except for a large inversion from trnGGCC to ycf3 in V. coerulea. Moreover, six CDSs and five non-CDSs were selected as candidate DNA barcodes. Our phylogenetic analyses demonstrated that Vanda s.l. is a monophyletic group with high supporting values based on five different datasets (complete plastome with one IR, 68 CDSs, LSC, five hypervariable non-CDSs, and six hypervariable CDSs), while the phylogenetic relationships among species were fully resolved based on the complete plastome with one IR dataset. Our results confirmed that the complete plastome has a great power in resolving the phylogenetic relationships of recently radiated lineages.

Identification and Analysis of Aluminum-Activated Malate Transporter Gene Family Reveals Functional Diversification in Orchidaceae and the Expression Patterns of Dendrobium catenatum Aluminum-Activated Malate Transporters.

Aluminum-activated malate transporter (ALMT) genes play an important role in aluminum ion (Al3+) tolerance, fruit acidity, and stomatal movement. Although decades of research have been carried out in many plants, there is little knowledge about the roles of ALMT in Orchidaceae. In this study, 34 ALMT genes were identified in the genomes of four orchid species. Specifically, ten ALMT genes were found in Dendrobium chrysotoxum and D. catenatum, and seven were found in Apostasia shenzhenica and Phalaenopsis equestris. These ALMT genes were further categorized into four clades (clades 1-4) based on phylogenetic relationships. Sequence alignment and conserved motif analysis revealed that most orchid ALMT proteins contain conserved regions (TM1, GABA binding motif, and WEP motif). We also discovered a unique motif (19) belonging to clade 1, which can serve as a specifically identified characteristic. Comparison with the gene structure of AtALMT genes (Arabidopsis thaliana) showed that the gene structure of ALMT was conserved across species, but the introns were longer in orchids. The promoters of orchid ALMT genes contain many light-responsive and hormone-responsive elements, suggesting that their expression may be regulated by light and phytohormones. Chromosomal localization and collinear analysis of D. chrysotoxum indicated that tandem duplication (TD) is the main reason for the difference in the number of ALMT genes in these orchids. D. catenatum was chosen for the RT-qPCR experiment, and the results showed that the DcaALMT gene expression pattern varied in different tissues. The expression of DcaALMT1-9 was significantly changed after ABA treatment. Combining the circadian CO2 uptake rate, titratable total acid, and RT-qPCR data analysis, most DcaALMT genes were highly expressed at night and around dawn. The result revealed that DcaALMT genes might be involved in photosynthate accumulation. The above study provides more comprehensive information for the ALMT gene family in Orchidaceae and a basis for subsequent functional analysis.

Climate change will decrease the coverage of suitable niches for Asian medicinal orchid (Bulbophyllum odoratissimum) and its main phorophyte (Pistacia weinmannifolia).

Considering the global biodiversity crisis and the growing demand for medicinal plants, it is crucial to preserve therapeutically useful herbs. From a conservation management perspective under climate change, identifying areas that enable valuable natural resources to persist in the future is crucial. Machine learning-based models are commonly used to estimate the locations of climate refugia, which are critical for the effective species conservation. The aim of this study was to assess the impact of global warming on the epiphytic medicinal orchid-Bulbophyllum odoratissimum. Given how the long-term survival of plants inhabiting shrubs and trees depends on the availability of suitable phorophyets, in this research potential range changes in reported orchid plant hosts were evaluated. According to conducted analyses, global warming will cause a decline in the coverage of the suitable niches for B. odoratissimum and its main phorophyte. The most significant habitat loss in the case of the studied orchid and Pistacia weinmannifolia will be observed in the southern part of their geographical ranges and some new niches will simultaneously become available for these plants in the northern part. Climate change will significantly increase the overlap of geographical ranges of P. weinmannifolia and the orchid. In the SSP5-8.5 scenario trees will be available for more than 56% of the orchid population. Other analyzed phorophytes, will be available for B. odoratissimum to a very reduced extent, as orchids will only utilize these species as habitats only occasionally. This study provides data on the distribution of climatic refugia of B. odoratissimum under global warming. Moreover, this is the first evaluation of the future geographical ranges for its phorophytes. According to the conducted analyses, only one of the previously reported tree species which are inhabited by B. odoratissimum, P. weinmannifolia, can serve as a phorophyte for this orchid in the future. In this study, the areas designated as suitable for the occurrence of both orchids and their phorophytes should be considered priority conservation areas for the studied medicinal plants.

Comprehensive Screening and Characterization of α-glucosidase Inhibitory Components in the Edible Medicinal Plant Pholidota cantonensis Rolfe Using UPLC-Q-TOF-MS/MS Analysis and Molecular Docking.

Pholidota cantonensis Rolfe is an edible medicinal plant in the genus Pholidota of the family Orchidaceae. This plant is used to prepare medicated food in China and has been reported to possess anti-α-glucosidase activity. To date, little is known about the active substances responsible for the observed anti-α-glucosidase activity. In the present study, we aimed to screen and characterize the α-glucosidase inhibitory fraction of P. cantonensis using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) analysis and molecular docking. As a result, the 50% ethanol fraction obtained from D101 macroporous adsorption resin column chromatography (D50 fraction) had the highest total phenol content (353.83 ± 6.06 mg GAE/g) and the most prominent α-glucosidase inhibitory activity (IC50 = 30.01 ± 7.30 µg/mL). Forty-five compounds were identified from the D50 fraction by using UPLC-Q-TOF-MS/MS analysis. Molecular docking results showed that six main constituents, namely, crepidatin, 2,7-dihydroxy-4-methoxyl-9,10-dihydrophenylene, 4,4',5,6-tetrahydroxystilbene, 4,7-dihydroxy-2-methoxyl-9,10-dihydrophenylene, (-)-lariciresinol, and thunalbene, in the D50 fraction occupied the catalytic sites of α-glucosidase through strong hydrophobic interactions, hydrogen bonding, and other patterns. The binding energies were between - 29.95 and - 11.41 kJ/mol, indicating good binding between the tested compounds and α-glucosidase. The active ingredients responsible for the α-glucosidase inhibitory activity may include phenanthrenes, stilbenes, dibenzyls, and lignans. The D50 fraction has potential value for developing innovative drugs for the prevention and treatment of diabetes mellitus (DM) and is worthy of in-depth research.

Multifunctional nanofibrous scaffolds for enhancing full-thickness wound healing loaded with Bletilla striata polysaccharides.

The considerable challenge of wound healing remains. In this study, we fabricated a novel multifunctional core-shell nanofibrous scaffold named EGF@BSP-CeO2/PLGA (EBCP), which is composed of Bletilla striata polysaccharide (BSP), Ceria nanozyme (CeO2) and epidermal growth factor (EGF) as the core and poly(lactic-co-glycolic acid) (PLGA) as the shell via an emulsion electrospinning technique. An increase in the BSP content within the scaffolds corresponded to improved wound healing performance. These scaffolds exhibited increased hydrophilicity and porosity and improved mechanical properties and anti-UV properties. EBCP exhibited sustained release, and the degradation rate was <4 % in PBS for 30 days. The superior biocompatibility was confirmed by the MTT assay, hemolysis, and H&E staining. In addition, the in vitro results revealed that, compared with the other groups, the EBCP group presented excellent antioxidant and antibacterial effects. More importantly, the in vivo results indicated that the wound closure rate of the EBCP group reached 94.0 % on day 10 in the presence of H2O2. The results demonstrated that EBCP could comprehensively regulate the wound microenvironment, possess hemostatic abilities, and significantly promote wound healing. In conclusion, the EBCP is promising for facilitating the treatment of infected wounds and represents a potential material for clinical applications.

Structural characteristics and wound-healing effects of Bletilla striata fresh tuber polysaccharide.

A homogeneous polysaccharide from Bletilla striata fresh tuber (BSPS) was prepared and extensively characterized using HP-GPC, colorimetry, FT-IR, methylation, GC-MS, NMR, Congo red experiment, SEM, and AFM. The molecular weight of BSPS was 722.90 kDa. BSPS consisted of glucose and mannose in the molar ratio of 1 : 2.5. BSPS had a linear chain structure consisting mainly of →4)-ß-d-Glcp-(1→ and →4)-ß-d-Manp-(1→ residues. O-acetyl group linked to C2 of →4)-ß-d-Manp-(1→ residue. Its monosaccharide molar ratio, molecular weight, and O-acetyl substituted position were different from that of the polysaccharide from B. striata dried tuber reported previously. Furthermore, BSPS at concentrations of 3.125-25 µg/mL significantly promoted the viability (ca. 10%), differentiation (1.5-4 folds), migration (15%-70%), and invasion (1.84-4.65 folds) of C2C12 cells. Of note, BSPS remarkably accelerated the epidermal regeneration and wound healing in mice. This study for the first time reported the structure of polysaccharides in B. striata fresh tubers. The results demonstrated that BSPS could be explored as a novel natural wound-healing drug.

Integrating Physiology, Cytology, and Transcriptome to Reveal the Leaf Variegation Mechanism in Phalaenopsis Chia E Yenlin Variegata Leaves.

Phalaenopsis orchids, with their unique appearance and extended flowering period, are among the most commercially valuable Orchidaceae worldwide. Particularly, the variegation in leaf color of Phalaenopsis significantly enhances the ornamental and economic value and knowledge of the molecular mechanism of leaf-color variegation in Phalaenopsis is lacking. In this study, an integrative analysis of the physiology, cytology, and transcriptome profiles was performed on Phalaenopsis Chia E Yenlin Variegata leaves between the green region (GR) and yellow region (YR) within the same leaf. The total chlorophyll and carotenoid contents in the YR exhibited a marked decrease of 72.18% and 90.21%, respectively, relative to the GR. Examination of the ultrastructure showed that the chloroplasts of the YR were fewer and smaller and exhibited indistinct stromal lamellae, ruptured thylakoids, and irregularly arranged plastoglobuli. The transcriptome sequencing between the GR and YR led to a total of 3793 differentially expressed genes, consisting of 1769 upregulated genes and 2024 downregulated genes. Among these, the chlorophyll-biosynthesis-related genes HEMA, CHLH, CRD, and CAO showed downregulation, while the chlorophyll-degradation-related gene SGR had an upregulated expression in the YR. Plant-hormone-related genes and transcription factors MYBs (37), NACs (21), ERFs (20), bHLH (13), and GLK (2), with a significant difference, were also analyzed. Furthermore, qRT-PCR experiments validated the above results. The present work establishes a genetic foundation for future studies of leaf-pigment mutations and may help to improve the economic and breeding values of Phalaenopsis.

Comparative Metabolome and Transcriptome Analyses of the Regulatory Mechanism of Light Intensity in the Synthesis of Endogenous Hormones and Anthocyanins in Anoectochilus roxburghii (Wall.) Lindl.

To explore the regulatory mechanism of endogenous hormones in the synthesis of anthocyanins in Anoectochilus roxburghii (Wall.) Lindl (A. roxburghii) under different light intensities, this study used metabolomics and transcriptomics techniques to identify the key genes and transcription factors involved in anthocyanin biosynthesis. We also analyzed the changes in and correlations between plant endogenous hormones and anthocyanin metabolites under different light intensities. The results indicate that light intensity significantly affects the levels of anthocyanin glycosides and endogenous hormones in leaves. A total of 38 anthocyanin-related differential metabolites were identified. Under 75% light transmittance (T3 treatment), the leaves exhibited the highest anthocyanin content and differentially expressed genes such as chalcone synthase (CHS), flavonol synthase (FLS), and flavonoid 3'-monooxygenase (F3'H) exhibited the highest expression levels. Additionally, 13 transcription factors were found to have regulatory relationships with 7 enzyme genes, with 11 possessing cis-elements responsive to plant hormones. The expression of six genes and two transcription factors was validated using qRT-PCR, with the results agreeing with those obtained using RNA sequencing. This study revealed that by modulating endogenous hormones and transcription factors, light intensity plays a pivotal role in regulating anthocyanin glycoside synthesis in A. roxburghii leaves. These findings provide insights into the molecular mechanisms underlying light-induced changes in leaf coloration and contribute to our knowledge of plant secondary metabolite regulation caused by environmental factors.

Extraction and characterization of hepatoprotective polysaccharides from Anoectochilus roxburghii against CCl4-induced liver injury via regulating lipid metabolism and the gut microbiota.

Anoectochilus roxburghii polysaccharides exhibit notable hepatoprotective effects, but the underlying substance basis and mechanisms remain unknown. In this study, four new polysaccharides named ARP-1a, ARP-1b, ARP-2a and ARP-2b, were isolated from A. roxburghii. Their structural characteristics were systematically analyzed using HPGPC, HPLC, GC-MS, IR and NMR analysis. ARP-1a, the leading polysaccharide isolated from A. roxburghii, was further evaluated for its hepatoprotective effects on acute liver injury mice induced by CCl4. ARP-1a significantly reduced the serum ALT, AST, TNF-α, IL-1ß and IL-6 levels, liver MDA content, and increased the SOD and CAT activities and GSH level in liver. H&E staining revealed that ARP-1a pretreatment could markedly relieve liver injury. Further mechanism exploration indicated that ARP-1a could relieve CCl4-induced oxidative damage through activating the Nrf2 signaling. In addition, metabolomics, lipidomics and 16S rRNA amplicon sequencing were used to elucidate the underlying mechanisms of ARP-1a. Multi-omics analysis indicated that ARP-1a exerted hepatoprotective effect against CCl4-induced acute liver injury by regulating lipid metabolism and modulating the gut microbiota. In conclusion, the above results suggest that ARP-1a can be considered a promising and safe candidate for hepatoprotective drug, as well as a potential prebiotic for maintaining intestinal homeostasis and promoting human intestinal health.

Biosolids Treated as a Nutritional Alternative for in vitro Culture of Bowdichia Virgilioides Kunth.

The safe management of sewage waste is a current concern due to population growth and waste production. Biosolids, derived from sewage sludge treatment, are globally used as organic fertilizers, aligning with Sustainable Development Goal 6 for resource recycling. However, biosafety concerns arise due to the presence of metals and microplastics in biosolids, potentially impacting soil and water. This study investigated biosolids' use for in vitro cultivation of Bowdichia virgilioides Kunth. Results indicate that while biosolids can replace traditional nutritional media, balancing their concentration is crucial for optimizing plant growth. The WPM (Wood Plat Medium) remains essential for in vitro cultivation, but substituting it with biosolids at concentrations of up to 2 g L- 1 is feasible, providing similar plant development compared to the WPM medium. However, when combined, there is a complex and challenging interaction between biosolids and the culture medium.

Practical preparation of unsaturated very-long-chain fatty acids (VLCFAs) and very-long-chain alkene pollinator attractants.

To prepare very-long-chain fatty acids and alkenes (VLCFAs and VLC alkenes) that are known pollinator attractants for sexually deceptive orchids, and biosynthetic precursors thereof, we applied a methodology allowing us to prepare monounsaturated VLCFAs with chain lengths up to 28 carbons and VLC alkenes up to 31 carbons. We implemented a coupling reaction between commercially available terminal alkynes and bromoalkanoic acids to prepare VLCFAs, allowing the products to be formed in two steps. For VLC alkenes, with many alkyltriphenylphosphonium bromides commercially available, we applied a Wittig reaction approach to prepare (Z)-configured monoenes in a single step. Using practical methods not requiring special reagents or equipment, we obtained 11 VLCFAs in > 90% isomeric purity, and 17 VLC alkenes in > 97% isomeric purity. Such general and accessible synthetic methods are essential for chemical ecology and biochemistry research to aid researchers in unambiguously identifying isolated semiochemicals and their precursors.

A review on endophytic bacteria of orchids: functional roles toward synthesis of bioactive metabolites for plant growth promotion and disease biocontrol.

MAIN CONCLUSION: In this review, we have discussed the untapped potential of orchid endophytic bacteria as a valuable reservoir of bioactive metabolites, offering significant contributions to plant growth promotion and disease protection in the context of sustainable agriculture. Orchidaceae is one of the broadest and most diverse flowering plant families on Earth. Although the relationship between orchids and fungi is well documented, bacterial endophytes have recently gained attention for their roles in host development, vigor, and as sources of novel bioactive compounds. These endophytes establish mutualistic relationships with orchids, influencing plant growth, mineral solubilization, nitrogen fixation, and protection from environmental stress and phytopathogens. Current research on orchid-associated bacterial endophytes is limited, presenting significant opportunities to discover new species or genetic variants that improve host fitness and stress tolerance. The potential for extracting bioactive compounds from these bacteria is considerable, and optimization strategies for their sustainable production could significantly enhance their commercial utility. This review discusses the methods used in isolating and identifying endophytic bacteria from orchids, their diversity and significance in promoting orchid growth, and the production of bioactive compounds, with an emphasis on their potential applications in sustainable agriculture and other sectors.