Integrated metabolome, full-length sequencing, and transcriptome analyses unveil the molecular mechanisms of color formation of the canary yellow and red bracts of Bougainvillea × buttiana 'Chitra'.

Bougainvillea is a typical tropical flower of great ornamental value due to its colorful bracts. The molecular mechanism behind color formation is not well-understood. Therefore, this research conducted metabolome analysis, transcriptome analysis, and multi-flux full-length sequencing in two color bracts of Bougainvillea × buttiana 'Chitra' to investigate the significantly different metabolites (SDMs) and differentially expressed genes (DEGs). Overall, 261 SDMs, including 62 flavonoids and 26 alkaloids, were detected, and flavonols and betalains were significantly differentially accumulated among the two bracts. Furthermore, the complete-length transcriptome of Bougainvillea × buttiana was also developed, which contained 512 493 non-redundant isoforms. Among them, 341 210 (66.58%) displayed multiple annotations in the KOG, GO, NR, KEGG, Pfam, Swissprot, and NT databases. RNA-seq findings revealed that 3610 DEGs were identified between two bracts. Co-expression analysis demonstrated that the DEGs and SDMs involved in flavonol metabolism (such as CHS, CHI, F3H, FLS, CYP75B1, kaempferol, and quercetin) and betacyanin metabolism (DODA, betanidin, and betacyanins) were the main contributors for the canary yellow and red bract formation, respectively. Further investigation revealed that several putative transcription factors (TFs) might interact with the promoters of the genes mentioned above. The expression profiles of the putative TFs displayed that they may positively and negatively regulate the structural genes' expression profiles. The data revealed a potential regulatory network between important genes, putative TFs, and metabolites in the flavonol and betacyanin biosynthesis of Bougainvillea × buttiana 'Chitra' bracts. These findings will serve as a rich genetic resource for future studies that could create new color bracts.

Transcriptomic profiling and gene network analysis revealed regulatory mechanisms of bract development in Bougainvillea glabra.

BACKGROUND: Bracts are important for ornamental plants, and their developmental regulation process is complex; however, relatively little research has been conducted on bracts. In this study, physiological, biochemical and morphological changes in Bougainvillea glabra leaves, leaf buds and bracts during seven developmental periods were systematically investigated. Moreover, transcriptomic data of B. glabra bracts were obtained using PacBio and Illumina sequencing technologies, and key genes regulating their development were screened. RESULTS: Scanning electron microscopy revealed that the bracts develop via a process involving regression of hairs and a color change from green to white. Transcriptome sequencing revealed 79,130,973 bp of transcript sequences and 45,788 transcripts. Differential gene expression analysis revealed 50 expression patterns across seven developmental periods, with significant variability in transcription factors such as BgAP1, BgFULL, BgCMB1, BgSPL16, BgSPL8, BgDEFA, BgEIL1, and BgBH305. KEGG and GO analyses of growth and development showed the involvement of chlorophyll metabolism and hormone-related metabolic pathways. The chlorophyll metabolism genes included BgPORA, BgSGR, BgPPH, BgPAO and BgRCCR. The growth hormone and abscisic acid signaling pathways involved 44 and 23 homologous genes, and coexpression network analyses revealed that the screened genes BgAPRR5 and BgEXLA1 are involved in the regulation of bract development. CONCLUSIONS: These findings improve the understanding of the molecular mechanism of plant bract development and provide important guidance for the molecular regulation and genetic improvement of the growth and development of ornamental plants, mainly ornamental bracts.

Bougainvillea glabra Choisy bracts extract in free and liposomal forms reduce hyperplasia induced by let-60gain-of-function in Caenorhabditis elegans.

In this study, we evaluated the toxicological and antiproliferative effects of B. glabra Choisy bract extract (BGCE) in its free and loaded into liposomes forms administered to C. elegans mutants with let-60 gain-of-function (gf). Our results demonstrated that the concentration up to 75 µg CAE/mL of BGCE was safe for the worms. Notably, we developed BGCE-loaded liposomes to extend the pharmacological window up to 100 µg CAE/mL without toxicity. In addition, the extract and liposomes reduced the number and area of the multivulva formed in let-60 gf mutants. There was also an increase in the apoptotic signaling in the germline cells and increased longevity mediated through DAF-16 nuclear translocation with GST-4 activation in the treated animals. Our findings demonstrated that the BGCE-loaded liposomes possess antitumoral effects due to the activation of the apoptotic signaling and DAF-16 nuclear translocation.

Effects of Bougainvillea glabra leaf on growth, skin mucosal immune responses, and disease resistance in common carp Cyprinus carpio.

This study evaluated the effects of Bougainvillea glabra (BG) leaf as a feed supplement on growth, skin mucosal immune parameters, serum oxidative stress, expression of immune-related genes, and susceptibility to pathogen infection in carp Cyprinus carpio. Diets containing four different BG concentrations (g kg-1), i.e., 0 g (basal diet), 20 g (BG20), 30 g (BG30), 40 g (BG40), and 50 g (BG50), were fed to the carp (average weight: 14.03 ± 0.81 g) for 8 weeks. Skin mucosal immunological and serum antioxidant parameters were examined 8 weeks post-feeding. Growth performance was significantly higher in BG40. Among the examined skin mucosal immune parameters, lysozyme (33.79 ± 0.98 U mL-1), protein (6.88 ± 0.37 mg mL-1), immunoglobulin (IgM; 5.34 ± 0.37 unit-mg mL-1), and protease activity (3.18 ± 0.36%) were significantly higher in BG40 than in the control; whereas, there was no significant effect on the alkaline phosphatase level. Among serum immune activity, activities of lysozyme, the alternative complement pathway, and IgM were significantly higher in BG40. Phagocytic, and superoxide dismutase (SOD) activities were higher (P < 0.05) in BG30-BG50. Serum ALT, AST, and MDA levels were lower in BG40 than in the control (P < 0.05). Intestinal enzymatic activities were enhanced in BG40 and BG50 (P < 0.05), except for lipase in BG50. Gene expression analysis revealed that the mRNA expressions of antioxidant genes (SOD, GPx, and Nrf2), an anti-inflammatory gene (IL-10), and IκBα were significantly upregulated in BG40. Conversely, the pro-inflammatory gene IL-1ß and the signaling molecule NF-κB p65 were downregulated in BG40 and BG50, respectively. BG supplementation had no significant effect on TNF-α, TLR22, or HSP70 mRNA expressions. Moreover, fish in BG40 exhibited the highest relative post-challenge survival (67.74%) against Aeromonas hydrophila infection. These results suggested that dietary supplementation with BG leaves at 40 g/kg can significantly improve the growth performance, immune responses, and disease resistance of C. carpio. BG leaves are a promising food additive for carp in aquaculture.

Comparative Analyses of Chloroplast Genome Provide Effective Molecular Markers for Species and Cultivar Identification in Bougainvillea.

Bougainvillea is popular in ornamental horticulture for its colorful bracts and excellent adaptability, but the complex genetic relationship among this genus is fuzzy due to limited genomic data. To reveal more genomic resources of Bougainvillea, we sequenced and assembled the complete chloroplast (cp) genome sequences of Bougainvillea spectabilis 'Splendens'. The cp genome size was 154,869 bp in length, containing 86 protein-coding genes, 38 tRNAs, and eight rRNAs. Cp genome comparison across 12 Bougainvillea species (B. spectabilis, B. glabra, B. peruviana, B. arborea, B. praecox, B. stipitata, B. campanulata, B. berberidifolia, B. infesta, B. modesta, B. spinosa, and B. pachyphylla) revealed five mutational hotspots. Phylogenetic analysis suggested that B. spectabilis published previously and B. glabra clustered into one subclade as two distinct groups, sister to the subclade of B. spectabilis 'Splendens'. We considered the phylogeny relationships between B. spectabilis and B. glabra to be controversial. Based on two hypervariable regions and three common plastid regions, we developed five molecular markers for species identification in Bougainvillea and applied them to classify 53 ornamental Bougainvillea cultivars. This study provides a valuable genetic resource for Bougainvillea breeding and offers effective molecular markers to distinguish the representative ornamental species of Bougainvillea.

Complete Chloroplast Genomes and Phylogenetic Relationships of Bougainvillea spectabilis and Bougainvillea glabra (Nyctaginaceae).

Bougainvillea L. (Nyctaginaceae) is a South American native woody flowering shrub of high ornamental, economic, and medicinal value which is susceptible to cold damage. We sequenced the complete chloroplast (cp) genome of B. glabra and B. spectabilis, two morphologically similar Bougainvillea species differing in cold resistance. Both genomes showed a typical quadripartite structure consisting of one large single-copy region, one small single-copy region, and two inverted repeat regions. The cp genome size of B. glabra and B. spectabilis was 154,520 and 154,542 bp, respectively, with 131 genes, including 86 protein-coding, 37 transfer RNA, and 8 ribosomal RNA genes. In addition, the genomes contained 270 and 271 simple sequence repeats, respectively, with mononucleotide repeats being the most abundant. Eight highly variable sites (psbN, psbJ, rpoA, rpl22, psaI, trnG-UCC, ndhF, and ycf1) with high nucleotide diversity were identified as potential molecular markers. Phylogenetic analysis revealed a close relationship between B. glabra and B. spectabilis. These findings not only contribute to understanding the mechanism by which the cp genome responds to low-temperature stress in Bougainvillea and elucidating the evolutionary characteristics and phylogenetic relationships among Bougainvillea species, but also provide important evidence for the accurate identification and breeding of superior cold-tolerant Bougainvillea cultivars.

Elevated NO2 induces leaf defensive mechanisms in Bougainvillea spectabilis seedlings.

With a growing economy, the living standard of people has improved which has led to increased use of urban motor vehicles globally. Consequently, the concentration of nitrogen dioxide (NO2) has increased in the ambient air, becoming a major pollutant in urban areas. Plant leaves can absorb, adsorb and fix nitrogen oxides to some extent. Interestingly, NO2 has been recognized as a positive/negative regulator of plant growth. To comprehensively understand the effect of NO2-induced pollution on plants, Bougainvillea spectabilis seedlings were fumigated with different concentrations of nitrogen dioxide (NO2) for a short period in the current study. Further, the induced morphological, physiological, and biochemical changes were measured in the treated as well as untreated seedlings. NO2 exposure caused yellow-brown spotting on the leaf blades in B. spectabilis, which could be the symptoms of oxidative damage. Our findings also reflected the changes in antioxidant enzyme activity and peroxidation of membrane lipids. In addition, the levels of osmotic regulatory substances were also found to be altered to different degrees. In addition, the activities of nitrogen metabolism-related enzymes varied, mainly affecting amino acid metabolism. Overall, the current study would provide a theoretical and scientific basis for selecting and allocating plants in NO2-contaminated areas to manage the pollutants level.

First report of Bougainvillea spectabilis Willd bacterial leaf spot caused by Pantoea stewartii subspecies indologenes in China.

Bougainvillea spectabilis Willd. is an important ornamental flowering plant belonging to the family Nyctaginaceae. It is widely used in landscape designs in tropical and subtropical regions. In December 2020, severe disease-causing leaf spots were discovered on the leaves of B. spectabilis in the Modern Agricultural Park (110°19' E, 21°26' N) Zhanjiang City, Guangdong Province, China. Field surveys revealed that the disease was widespread, with an incidence of 60-80%. Early symptoms on the leaves appeared as tiny leaf spots that later developed into concentric circles surrounded by a yellowish halo (Fig. 1). Diseased leaves with typical symptoms were collected for pathogen isolation. The leading edges of the lesions were excised, sanitized in 75% ethanol for 30 s and in 3% sodium hypochlorite for 3 min, and rinsed three times with sterile distilled water (SDW). The diseased tissue was crushed in 1 mL SDW, soaked for 15 min, and then spread onto nutrient agar medium on a petri dish. Circular, bright yellow colonies with smooth margins were observed after 24 h of incubation at 28 °C. The isolate (SJM1) was a gram-negative bacillus with positive results for catalase, indole synthesis, maltose, and arbutin and negative results for sorbitol, lactose, salicin, and starch hydrolysis. The SJM1 genomic DNA was extracted using the TIANamp Bacterial DNA Kit, and partial 16S rDNA gene segments were amplified using the bacterial generic primers 27F and 1492R. The collated 16S rDNA gene sequences were submitted to the NCBI GenBank (MZ723935). BLAST analysis of the sequences revealed 99.38% identity with Pantoea stewartii (MG517424.1). Amplification using subspecies-specific primers galE (#562/564; Gehring et al. 2014), glmS (#356/341; Wensing et al. 2010), and pstC + pstS (#338/339; Wensing et al. 2010) revealed that the genes showed 99-100% identity with P. stewartii subsp. indologenes (galE = 100%, MZ754494.1; glmS = 99.79%, MZ75496.1; and pstC + pstS = 99.89%, MZ754495.1). Phylogenetic trees were constructed using the neighbor-joining method (MEGA X), with both the 16S rDNA sequence (Fig. 2 2A) and the concatenated 16S rDNA, galE, pstC + pstS, and glmS sequences (Fig.2 2B). The SJM1 isolate belonged to the same clade as P. stewartii subsp. indologenes and was 99% homologous to P. stewartii subsp. indologenes strain ZJ-FGZX1 (Fig. 2 2B; Ren et al. 2020). Pathogenicity tests were performed through prick wound inoculation. Sterile needles were used to create fresh wounds on healthy young leaves of one-year-old B. spectabilis plants. Wounds were inoculated with 20 µl bacterial suspension (1 × 108 CFU/ml) or SDW. Four leaves per plant and three plants per treatment were evaluated. The plants were incubated at 28 °C temperature and 80-90% relative humidity. After 4-7 days of inoculation, all plants inoculated with the bacterial suspension had spot symptoms with a halo, similar to those observed in the field. However, leaves inoculated with SDW alone did not show any symptoms. Furthermore, the colony morphology and 16S rDNA sequences of the strains isolated from the inoculated leaves were identical to those of the original isolates. These results verified Koch's postulates. Based on biochemical identification and sequencing analysis, the pathogen causing B. spectabilis leaf spot was identified as P. stewartii subsp. indologenes. Previous reports have shown that P. stewartii subsp. indologenes can cause diseases in Dracaena sanderiana, Cenchrus americanus, and Allium cepa (Zhang et al. 2020, Ashajyothi et al. 2021, Stumpf et al. 2018). To our knowledge, this is the first report of P. stewartii subsp. indologenes causing B. spectabilis leaf spot disease in China.

Composition, Color Stability and Antioxidant Properties of Betalain-Based Extracts from Bracts of Bougainvillea.

Betalains in bracts of Bougainvillea are of great application potential as natural food colorants and antioxidants. This study explored the color, spectra, composition, storage stability, and antioxidant properties of betalain-based Bougainvillea bracts extracts (BBEs) to verify their application value. The results showed that Bougainvillea bract color variance is due to varied contents and proportions of betacyanins (Bc) and betaxanthins (Bx). Bc or Bx alone determined hues of purple or yellow, respectively; the co-existence of Bc and Bx would produce varied hues of red. BBEs showed bright color and good antioxidant properties under a wide pH range. The pH range of 5−6 was optimal for the highest color stability, and pHs 3−8 were optimal for stronger antioxidants. Bc mainly underwent color fading during storage, while Bx easily produced dark precipitates or melanism under strong acidic (pH < 4) or alkaline conditions (pH > 8). However, Bougainvillea Bx showed 3−4 times higher antioxidant ability than Bc. Different considerations for Bc and Bx are needed for varied application purposes. The purple bracts containing only Bc would be more suitable as colorant sources, while additional Bx can bring enhancement of antioxidant ability and richness of Bougainvillea extract color.

Chemical Composition, Antioxidant Activity, Cytoprotective and In Silico Study of Ethanolic Extracts of Bougainvillea × buttiana (Var. Orange and Rose).

Bougainvillea × buttiana is a plant widely used in traditional Mexican medicine and other parts of the world for the treatment of various health disorders. In this study, the antioxidant and cytoprotective activities of three ethanolic extracts of B. × buttiana (BxbO (Orange), BxbR1 (Rose1) and BxbR2 (Rose2)) were investigated. Antioxidant activities were determined by the oxygen radical absorbance capacity (ORAC), DPPH free radicals scavenging activity, and radical scavenging effects on nitric oxide (NO). The in vitro cytoprotective effect of the extracts against oxidative stress induced by hydrogen peroxide-(H2O2) in a model of L929 cells was also determined as well as NO uptake with or without H2O2 through the MTT assay. The results revealed that there was a difference between the compounds present in each of the extracts, with the 2-Hydroxycinnamic acid compound being observed in all the extracts. The 2-Hydroxycinnamic acid compound was tested in silico to predict its biological (PASSonline) and toxicological (Osiris Property Explorer) activity. All extracts with 1 to 4 mg/mL inhibited the activity of the NO radical. In cells exposed to 1 mg/mL of extracts followed by H2O2 exposure, cell protection ranged from 66.96 to 83.46%. The treatment of the cells with extracts prevented the morphological changes caused by H2O2. The 2-Hydroxycinnamic acid compound showed a probability of in silico antioxidant and cytoprotective activity greater than 0.5 and 0.6, respectively. Therefore, the results demonstrated that Bxb extracts exert antioxidant and protective activities against H2O2-induced oxidative stress in L929 cells.

Post-transcriptional gene silencing of CYP76AD controls betalain biosynthesis in bracts of bougainvillea.

Betalain is one of four major plant pigments and shares some features with anthocyanin; however, no plant has been found to biosynthesize both pigments. Previous studies have reported that anthocyanin biosynthesis in some plants is regulated by post-transcriptional gene-silencing (PTGS), but the importance of PTGS in betalain biosynthesis remains unclear. In this study, we report the occurrence of PTGS in betalain biosynthesis in bougainvillea (Bougainvillea peruviana) 'Thimma', which produces bracts of three different color on the same plant, namely pink, white, and pink-white. This resembles the unstable anthocyanin pigmentation phenotype that is associated with PTGS, and hence we anticipated the presence of PTGS in the betalain biosynthetic pathway. To test this, we analysed pigments, gene expression, small RNAs, and transient overexpression. Our results demonstrated that PTGS of BpCYP76AD1, a gene encoding one of the betalain biosynthesis enzymes, is responsible for the loss of betalain biosynthesis in 'Thimma'. Neither the genetic background nor DNA methylation in the BpCYP76AD1 sequence could explain the induction of PTGS, implying that another locus controls the unstable pigmentation. Our results indicate that naturally occurring PTGS contributes to the diversification of color patterns not only in anthocyanin biosynthesis but also in betalain biosynthesis.

Evaluation of bioactivity of aqueous extracts of Bougainvillea spectabilis, Saraca asoca, and Chenopodium album against immature forms of Aedes aegypti.

BACKGROUND: Increasing rate of vector transmission of dengue has led to the exponential rise in the mortality and morbidity scales in the past five years. There are various natural and synthetic chemical agents available commercially as potent larvicides, but they are either highly toxic, difficult to obtain, have a high manufacturing cost, or show cross-resistance, hence do not suffice as ideal larvicides. The objective was to screen aqueous extracts of Bougainvillea spectabilis (B. spectabilis), Saraca asoca (S.asoca), and Chenopodium album (C. album) for larvicidal activity against Aedes aegypti (A. aegypti). METHODS: The larvae were exposed to increasing concentrations of aqueous extracts of B. spectabilis, S. asoca, and C. album under controlled laboratory environment. The mortality was checked after 24 hours, results were statistically analyzed, and LC50 and LC90 were determined. RESULTS: B. spectabilis and S. asoca were found effective as larvicides against A. aegypti with LC50 values of 0.22% and 0.26%, respectively. CONCLUSION: The aqueous extracts of B . spectabilis and S. asoca are efficient larvicides against A . aegypti and can be used as effective, accessible, and eco-friendly control options for management of A. aegypti, the vector of dengue/chikungunya.

Subcellular distribution and chemical forms of Cd in Bougainvillea spectabilis Willd. as an ornamental phytostabilizer: An integrated consideration.

The effects of Cd stress on the growth and Cd accumulation of Bougainvillea spectabilis Willd. as an ornamental plant and the related mechanisms were investigated in the study. We studied the impact of Cd on the plant ultrastructure, examined the cellular distribution of Cd, explored the Cd chemical forms and transformation, and determined the organic acid secretion in the plants. The results showed that B. spectabilis could grow well in the Cd treatment groups, and the roots could accumulate high concentration of Cd. The soluble fraction (primarily in the vacuole) as the form of citrate in leaves of B. spectabilis was the major compartment for Cd storage. The citric acid secreted by B. spectabilis played an important role in the detoxification of Cd, as well as the growth of plants and Cd accumulation. As an ornamental plant, B. spectabilis has the potential to be used in the phytostabilization of Cd-contaminated soils and can beautify the environment at the same time.

Antioxidant Activity of Bougainvillea spectabilis Bracts as an Alternative to Nitrites in Cooked Pork Ham.

In this study, the impact of incorporating Bougainvillea spectabilis powder into ham formulation as a potential color replacement for nitrites was evaluated. Three drying methods were proposed to preserve the antioxidant properties of bougainvillea: foam-mat drying, air drying, and oven drying. Antioxidant assays (DPPH, ABTS, and FRAP) assays revealed that the presence of bougainvillea powders enhanced the antioxidant properties and maintained the stability of the ham over 8 weeks of storage at 4 °C. In addition, total polyphenolic content and presence of thiobarbituric acid reactive substances (TBARS) were evaluated and showed higher and lower scores, respectively, in the samples with the incorporation of bougainvillea compared to the control samples, suggesting their potential to replace nitrite salts by providing natural antioxidant protection. Sensorial analysis also revealed no significant differences in sensory attributes in hams with 0.1% bougainvillea powder compared to nitrite samples. The incorporation of the bougainvillea powders in the ham formulation improved the sensorial attributes and consumer overall acceptance even after 8-week cold storage at 4 °C.

Physiological Responses and Salt Tolerance Evaluation of Different Varieties of Bougainvillea under Salt Stress.

Soil salinization significantly impacts the ecological environment and agricultural production, posing a threat to plant growth. Currently, there are over 400 varieties of Bougainvillea with horticultural value internationally. However, research on the differences in salt tolerance among Bougainvillea varieties is still insufficient. Therefore, this study aims to investigate the physiological responses and tolerance differences of various Bougainvillea varieties under different concentrations of salt stress, reveal the effects of salt stress on their growth and physiology, and study the adaptation mechanisms of these varieties related to salt stress. The experimental materials consisted of five varieties of Bougainvillea. Based on the actual salinity concentrations in natural saline-alkali soils, we used a pot-controlled salt method for the experiment, with four treatment concentrations set: 0.0% (w/v) (CK), 0.2% (w/v), 0.4% (w/v), and 0.6% (w/v). After the Bougainvillea plants grew stably, salt stress was applied and the growth, physiology, and salt tolerance of the one-year-old plants were systematically measured and assessed. The key findings were as follows: Salt stress inhibited the growth and biomass of the five varieties of Bougainvillea; the 'Dayezi' variety showed severe salt damage, while the 'Shuihong' variety exhibited minimal response. As the salt concentration and duration of salt stress increase, the trends of the changes in antioxidant enzyme activity and osmotic regulation systems in the leaves of the five Bougainvillea species differ. Membrane permeability and the production of membrane oxidative products showed an upward trend with stress severity. The salt tolerance of the five varieties of Bougainvillea was comprehensively evaluated through principal component analysis. It was found that the 'Shuihong' variety exhibited the highest salt tolerance, followed by the 'Lvyehuanghua', 'Xiaoyezi', 'Tazi', and 'Dayezi' varieties. Therefore, Bougainvillea 'Shuihong', 'Lvyehuanghua', and 'Xiaoyezi' are recommended for extensive cultivation in saline-alkali areas. The investigation focuses primarily on how Bougainvillea varieties respond to salt stress from the perspectives of growth and physiological levels. Future research could explore the molecular mechanisms behind the responses to and tolerance of different Bougainvillea varieties as to salt stress, providing a more comprehensive understanding and basis for practical applications.

Extraction and characterization of Bougainvillea glabra fibers: A study on chemical, physical, mechanical and morphological properties.

Bougainvillea glabra fibers (BGFs) present a promising avenue for sustainable material development owing to their abundance and favorable properties. This study entails a thorough investigation into the composition, physical characteristics, mechanical behavior, structural properties, thermal stability, and hydrothermal absorption behavior of BGFs. Chemical analysis reveals the predominant presence of cellulose (68.92 %), accompanied by notable proportions of hemicellulose (12.64 %), lignin (9.56 %), wax (3.72 %), moisture (11.78 %), and ash (1.75 %). Physical measurements ascertain a mean fiber diameter of approximately 232.63 ± 8.59 µm, while tensile testing demonstrates exceptional strength, with stress values ranging from 120 ± 18.26 MPa to a maximum of 770 ± 23.19 MPa at varying strains. X-ray diffraction (XRD) elucidates a crystalline index (CI) of 68.17 % and a crystallite size (CS) of 9.42 nm, indicative of a well-defined crystalline structure within the fibers. Fourier-transform infrared spectroscopy (FTIR) confirms the presence of characteristic functional groups associated with cellulose, hemicellulose, wax, and water content. Thermogravimetric analysis (TGA) delineates distinct thermal degradation stages, with onset temperatures ranging from 102.76 °C for water loss to 567.55 °C for ash formation. Furthermore, hydrothermal absorption behavior exhibits temperature and time-dependent trends, with absorption percentages ranging from 15.26 % to 32.19 % at temperatures between 30 °C and 108 °C and varying exposure durations. These comprehensive findings provide essential insights into the properties and potential applications of BGFs in diverse fields such as bio-composites, textiles, and environmentally friendly packaging solutions.

Mechanistic analysis of the hardening process of the thorns on stems of Bougainvillea glabra "Elizabeth Angus".

Introduction: Bougainvillea glabra "Elizabeth Angus" is a thorny woody vine or shrub. However, the hard thorns are considered a deficiency in its ornamental value. Methods: To find the genes and pathways related to the hardening process of the thorns on the stems of B. glabra, the eukaryotic unreferenced transcriptome sequencing analysis was conducted to explore the 3 stages of the thorn-hardening process. Total RNA was extracted from thorns and stems, and transcriptome libraries were constructed and sequenced using unreferenced Illumina sequencing. Results: Gene function annotation was performed using various databases, resulting in 8937 co-annotated genes. The density distribution of Fragments Per Kilobase of transcript per Million mapped reads (FPKM) depicted the overall gene expression patterns. The study found that stage 2 as the period of highest gene expression activity during the thorns hardening process in B. glabra. Differential expression analysis revealed that during thorn-hardening, 1045 genes up-regulated and 391 genes down-regulated significantly in thorns at stage 2 compared to stage 1 (early stage of thorns formation). Meanwhile, 938 genes up-regulated and 784 genes down-regulated significantly in stems. At stage 3, as thorns became harder, 63 genes exhibited notable expression increase and 98 genes' expression decreased obviously within thorns, and 46 genes up-regulated and 29 genes down-regulated in stems, compared to stage 2. Phenylpropanoid biosynthesis was the key step in the hardening process of the thorns of B. glabra. The formation and hardening of thorns on the stem of B. glabra was a process in which lignin gradually accumulated in the thorns, and several genes were involved in this process. They include PAL (EC:4.3.1.24), CYP73A (EC:1.14.14.91), 4CL (EC:6.2.1.12), CCR (EC:1.2.1.44), CAD (EC:1.1.1.195) and POX (EC:1.11.1.7). Discussion: This transcriptome analysis offers insights into the molecular mechanisms underlying thorns development in this plant species.

Anthocyanins from pomegranate peel (Punica granatum), chili pepper fruit (Capsicum annuum), and bougainvillea flowers (Bougainvillea spectabilis) with multiple biofunctions: Antibacterial, antioxidant, and anticancer.

Background: Natural colorants, including natural pigments, e.g., anthocyanins, carotenoids, and chlorophylls, in novel and attractive food matrixes have become a popular trend. They impart favorite colors to food products and provide significant therapeutic effects. This study is aimed at extracting and identifying some natural pigments from different plant sources and evaluating their ability as antibacterial, antioxidant, and anticancer activities. Methods: The anthocyanin-rich extract (ARE) is derived from three natural plant sources: pomegranate peel (Punica granatum), chili pepper fruit (Capsicum annuum), and Bougainvillea flowers. Bougainvillea spectabilis are analyzed for biochemical composition, as well as antioxidant, antibacterial, and anticancer activity, HPLC, DPPH, FRAP, disc diffusion assay, MIC, MTT, VEGFR-2, and caspase-9 assays. Results: All three extracts had varying total phenolic contents, ranging from 14 to 466 mg GAE/g extract, where Punica granatum was the highest (466 mg GAE/g extract), followed by Bougainvillea spectabilis (180 mg GAE/g extract), and then Capsicum annuum (14 mg GAE/g extract). The antioxidant activity rose steadily with raising concentration. The ARE of pomegranate peels recorded highest value, followed by Bougainvillea flowers and chili pepper fruit. The MTT assay revealed an inhibitory action of the tested extracts on the proliferation of HCT-116, MCF-7, and HepG2 in a concentration-based manner. Gene expression of caspase-9 transcripts was considerably multiplied by the application of ARE of pomegranate peels. All the tested extracts inhibited VEGFR-2, and the inhibition (%) expanded gradually with increasing concentrations, achieving the highest value (80 %) at 10 µg/mL. The ARE of pomegranate peels scored highest antibacterial activity, followed by ARE of chili pepper fruit and Bougainvillea flowers. The inhibition zone diameter escalated gradually with rising concentrations of the tested samples. Conclusion: The AREs of the three studied plant sources can be used as multifunctional products with antioxidant, anticancer, and antibacterial activities that are natural, safe, and cheap.

Effect of Photoperiod Duration on Flower Bud Differentiation and Related Gene Expression in Bougainvillea glabra 'Sao Paulo'.

BACKGROUND: Environmental conditions, such as photoperiod, affect the developmental response of plants; thus, plants have evolved molecular mechanisms to adapt to changes in photoperiod. In Bougainvillea spp., the mechanism of flower formation underlying flowering control techniques remains poorly understood, and the physiological changes that occur during flower bud formation and the expression of related genes are not yet fully understood. METHODS: In this study, we induced flowering of potted Bougainvillea glabra 'Sao Paulo' plants under light-control treatments and analyzed their effects on flowering time, number of flower buds, flowering quality, as well as quality of flower formation, which was analyzed using transcriptome sequencing. RESULTS: Light-control treatment effectively induced the rapid formation of flower buds and early flowering in B. glabra 'Sao Paulo', with the time of flower bud formation being 119 days earlier and the flowering period extended six days longer than those of the control plants. The light-control treatment caused the bracts to become smaller and lighter in color, while the number of flowers increased, and the neatness of flowering improved. Transcriptome sequencing of the apical buds identified 1235 differentially expressed genes (DEGs) related to the pathways of environmental adaptation, biosynthesis of other secondary metabolites, glycan biosynthesis and metabolism, and energy metabolism. DEGs related to gibberellin metabolism were analyzed, wherein five DEGs were identified between the control and treatment groups. Transcriptomic analysis revealed that the gibberellin regulatory pathway is linked to flowering. Specifically, GA and GID1 levels increased during this process, enhancing DELLA protein degradation. However, decreasing this protein's binding to CO did not halt FT upregulation, thereby advancing the flowering of B. glabra 'Sao Paulo'. CONCLUSIONS: The findings of our study have implications for future research on photoperiod and its role in controlling flowering timing of Bougainvillea spp.

Antinociceptive and Anti-Inflammatory Activities of Acetonic Extract from Bougainvillea x buttiana (var. Rose).

Background:Bougainvillea x buttiana is an ornamental plant with antioxidant, anti-inflammatory, and cytotoxic activities, which has been traditionally used to treat respiratory diseases. This study aimed to investigate whether the acetonic extract of Bougainvillea x buttiana var. Rose (BxbRAE-100%) has analgesic and anti-inflammatory properties and its potential action mechanisms. Methods: Analgesic and anti-inflammatory activities were evaluated using three murine pain models and two acute inflammation models. In vitro, the ability of the extract to inhibit proteolytic activity and the activities of the enzymes phospholipase A2 (PLA2) and cyclooxygenase (COX) were evaluated. In silico analysis was performed to predict the physicochemical and Absorption, distribution, metabolism, and excretion (ADME) profiles of the compounds previously identified in BxbRAE-100%. Results: In vivo BxbRAE-100% decreased the nociceptive behaviors in the writhing model, the tail immersion, and the formalin test, suggesting that the extract has the potential to relieve pain at peripheral and central levels. Additionally, topical or oral BxbRAE-100% treatment reduced dose-dependent 12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced ear inflammation and carrageenan-induced paw edema, respectively. In vitro, BxbRAE-100% significantly inhibited proteolytic activity and PLA2, COX-1 and COX-2 activities. In silico, the compounds previously identified in BxbRAE-100% met Lipinski's rule of five and showed adequate ADME properties. Conclusions: These results support the use of B. x buttiana in Traditional Mexican Medicine and highlight its potential for the development of new treatments for pain and inflammation.