Population Structure and Genetic Diversity of the Toona ciliata (Meliaceae) Complex Assayed with Chloroplast DNA Markers.

Toona ciliata is a deciduous or semi-deciduous tree species and belongs to the Toona genus of the Meliaceae family. Owing to low natural regeneration and over-exploitation, the species is listed as an endangered species at level II in China and its conservation has received increasing concern. Here, we sampled 447 individuals from 29 populations across the range-wide distribution of the T. ciliata complex in China and assessed their genetic variation using two chloroplast DNA markers. The results showed that the overall haplotype diversity and nucleotide diversity per site were high at h = 0.9767 and π = 0.0303 for the psbA-trnH fragment and h= 0.8999 and π = 0.0189 for the trnL-trnL fragment. Phylogenetic analysis supported the division of the natural distribution of T. ciliata complex into western and eastern regions. The genetic diversity was higher in the western region than in the eastern region, showing significant phylogeographic structure. Genetic differentiation among populations was moderate (Φst=42.87%), and the effects of isolation by distance (IBD) were significant. A neutrality test and mismatch distribution analysis indicated that the distribution of the T. ciliata complex generally did not expand, although a few local populations could likely expand after bottleneck effects. The overall results were complementary to and consolidated previous studies using mitochondrial and nuclear DNA markers. We finally discussed strategies for the genetic conservation of the T. ciliata complex.

Traditional Uses, Chemical Constituents and Pharmacological Activities of the Toona sinensis Plant.

Toona sinensis (A. Juss.) Roem., which is widely distributed in China, is a homologous plant resource of medicine and food. The leaves, seeds, barks, buds and pericarps of T. sinensis can be used as medicine with traditional efficacy. Due to its extensive use in traditional medicine in the ancient world, the T. sinensis plant has significant development potential. In this review, 206 compounds, including triterpenoids (1-133), sesquiterpenoids (134-135), diterpenoids (136-142), sterols (143-147), phenols (148-167), flavonoids (168-186), phenylpropanoids (187-192) and others (193-206), are isolated from the T. sinensis plant. The mass spectrum cracking laws of representative compounds (64, 128, 129, 154-156, 175, 177, 179 and 183) are reviewed, which are conducive to the discovery of novel active substances. Modern pharmacological studies have shown that T. sinensis extracts and their compounds have antidiabetic, antidiabetic nephropathy, antioxidant, anti-inflammatory, antitumor, hepatoprotective, antiviral, antibacterial, immunopotentiation and other biological activities. The traditional uses, chemical constituents, compound cracking laws and pharmacological activities of different parts of T. sinensis are reviewed, laying the foundation for improving the development and utilization of its medicinal value.

Physicochemical properties and solution conformation of polysaccharides from Toona sinensis (A. Juss) Roem leaves.

In this study, two polysaccharide fractions (TSP-1 and TSP-2) were isolated from Toona sinensis leaves. The physicochemical properties and solution conformations of TSP-1 and TSP-2 were investigated. DSC and TG results showed that TSP-1 and TSP-2 had thermal stability. The intrinsic viscosities of TSP-1 and TSP-2 solutions were 11.42 and 6.13 mL/g, respectively. Rheological results showed that the viscosities of TSP-1 and TSP-2 solutions were affected by polysaccharide concentration, Ca2+ and extreme pH. Furthermore, TSP-1 exhibited a weak gel behavior at the concentrations of 0.5 %-2.0 %, while TSP-2 showed a weak gel behavior at the concentration of 2 %. HPSEC-MALLS analysis revealed that the Rg values of TSP-1 and TSP-2 were 96.8 nm and 56.2 nm, respectively. Conformation analysis indicated that TSP-1 behaved as a sphere, while TSP-2 behaved like a rigid rod. These results suggest that TSP-1 and TSP-2 can be used as additives in food, pharmaceutical and cosmetic industries.

Integrated Transcriptomic and Metabolomic Analysis Reveal the Underlying Mechanism of Anthocyanin Biosynthesis in Toona sinensis Leaves.

Toona sinensis, commonly known as Chinese Toon, is a plant species that possesses noteworthy value as a tree and vegetable. Its tender young buds exhibit a diverse range of colors, primarily determined by the presence and composition of anthocyanins and flavonoids. However, the underlying mechanisms of anthocyanin biosynthesis in Toona sinensis have been rarely reported. To explore the related genes and metabolites associated with composition of leaf color, we conducted an analysis of the transcriptome and metabolome of five distinct Toona clones. The results showed that differentially expressed genes and metabolites involved in anthocyanin biosynthesis pathway were mainly enriched. A conjoint analysis of transcripts and metabolites was carried out in JFC (red) and LFC (green), resulting in the identification of 510 genes and 23 anthocyanin-related metabolites with a positive correlation coefficient greater than 0.8. Among these genes and metabolites, 23 transcription factors and phytohormone-related genes showed strong coefficients with 13 anthocyanin derivates, which mainly belonged to the stable types of delphinidin, cyanidin, peonidin. The core derivative was found to be Cyanidin-3-O-arabinoside, which was present in JFC at 520.93 times the abundance compared to LFC. Additionally, the regulatory network and relative expression levels of genes revealed that the structural genes DFR, ANS, and UFGT1 might be directly or indirectly regulated by the transcription factors SOC1 (MADS-box), CPC (MYB), and bHLH162 (bHLH) to control the accumulation of anthocyanin. The expression of these genes was significantly higher in red clones compared to green clones. Furthermore, RNA-seq results accurately reflected the true expression levels of genes. Overall, this study provides a foundation for future research aimed at manipulating anthocyanin biosynthesis to improve plant coloration or to derive human health benefits.

New steroid produced by Periconia pseudobyssoides K5 isolated from Toona sureni (Meliaceae) and its heme polymerization inhibition activity.

A new ergostane-type steroid named (22E)-3α,6α,9α-ergosta-7,22-diene-3,6,9-triol (1), along with six known steroids 5α,8α-epidioxy-24-ethyl-cholest-6-en-3ß-ol (2), ergosterol-5,8-peroxide (3), cerevisterol (4), isocyathisterol (5), 6ß-hydroxystigmast-4-en-3-one (6), 6ß-hydroxy-4-campesten-3-one (7), were isolated from the fermented unpolished rice media by Periconia pseudobyssoides K5 (Periconiaceae), an endophytic fungus from medicinal plant Toona sureni (Meliaceae). The fermentation takes at 28 ± 2 °C for 30 days. The structure of new steroid (1) was elucidated by extensive spectroscopic measurements (IR, HR-ESI-TOFMS, and 1D and 2D NMR) analyses. The isolated compounds (1-7) were evaluated for heme polymerization inhibition assay (HPIA). The IC50 HPIA value of 1 is 8.24 ± 0.03 mg/ml.

In Vitro Anti-Venom Potentials of Aqueous Extract and Oils of Toona ciliata M. Roem against Cobra Venom and Chemical Constituents of Oils.

There are high mortality and morbidity rates from poisonous snakebites globally. Many medicinal plants are locally used for snakebite treatment in Uganda. This study aimed to determine the in vitro anti-venom activities of aqueous extract and oils of Toona ciliata against Naja melanoleuca venom. A mixture of venom and extract was administered intramuscularly in rats. Anticoagulant, antiphospholipase A2 (PLA2) inhibition assay, and gel electrophoresis for anti-venom activities of oils were done. The chemical constituents of the oils of ciliata were identified using Gas chromatography-tandem mass spectroscopy (GC-MS/MS). The LD50 of the venom was 0.168 ± 0.21 µg/g. The venom and aqueous extract mixture (1.25 µg/g and 3.5 mg/g) did not cause any rat mortality, while the control with venom only (1.25 µg/g) caused death in 1 h. The aqueous extract of T. ciliata inhibited the anticoagulation activity of N. melanoleuca venom from 18.58 min. to 4.83 min and reduced the hemolytic halo diameter from 24 to 22 mm. SDS-PAGE gel electrophoresis showed that oils completely cleared venom proteins. GC-MS/MS analysis showed that the oils had sesquiterpene hydrocarbons (60%) in the volatile oil (VO) and oxygenated sesquiterpenes (48.89%) in the non-volatile oils (NVO). Some major compounds reported for the first time in T. ciliata NVOs were: Rutamarin (52.55%), ß-Himachalol (9.53%), Girinimbine (6.68%) and Oprea1 (6.24%). Most compounds in the VO were reported for the first time in T. ciliata, including the major ones Santalene (8.55%) and Himachal-7-ol (6.69%). The result showed that aqueous extract and oils of T. ciliata have anti-venom/procoagulant activities and completely neutralized the venom. We recommend a study on isolation and testing the pure compounds against the same venom.

Integrated transcriptomic and volatilomic profiles to explore the potential mechanism of aroma formation in Toona sinensis.

As an important quality determinant of Toona sinensis, the unique aroma largely impacts the purchasing behavior of consumers. However, the underlying formation mechanism of the characteristic aroma of T. sinensis remains poorly understood. In this work, integrative volatile/nonvolatile compounds profiling and RNA sequencing were used to characterize six T. sinensis cultivars. Volatile sulfur compounds (VSCs) and terpenoids were the main volatile organic compounds (VOCs) in T. sinensis, accounting for 36.95-67.27% and 17.75-31.36% of the total VOC content, respectively. Notably, the VOCs originated from terpenoid biosynthesis, and the degradation of unsaturated fatty acids (UFAs) played important roles in reconciling the irritating odor of VSCs. The above differential metabolic profiles are the main sources of the specific aroma of different T. sinensis cultivars. Furthermore, 13 volatile organic compounds were identified as potential biomarkers to distinguish these T. sinensis cultivars by chemometric analysis. Based on the analysis of transcriptomic datasets, the potential biosynthetic pathways of the key VSCs were firstly confirmed in T. sinensis. It was found that 1-propenylsulfenic acid is a crucial precursor in the formation of characteristic VSCs in T. sinensis. Additionally, two potential mechanisms were proposed to explain the differences of the key VSCs among six T. sinensis cultivars. These results provide theoretical guidance for improving the aroma quality of T. sinensis.

Sequencing and analysis of the complete mitochondrial genomes of Toona sinensis and Toona ciliata reveal evolutionary features of Toona.

BACKGROUND: Toona is a critical genus in the Meliaceae, and the plants of this group are an asset for both restorative and restorative purposes, the most flexible of which are Toona sinensis and Toona ciliata. To concentrate on the advancement of mitochondrial(Mt) genome variety in T.sinensis and T.ciliata, the Mt genomes of the two species were sequenced in high throughput independently, after de novo assembly and annotation to construct a Mt genome map for comparison in genome structure. Find their repetitive sequences and analyze them in comparison with the chloroplast genome, along with Maximum-likelihood(ML) phylogenetic analysis with 16 other relatives. RESULTS: (1) T. sinensis and T.ciliata are both circular structures with lengths of 683482 bp and 68300 bp, respectively. They share a high degree of similarity in encoding genes and have AT preferences. All of them have the largest Phe concentration and are the most frequently used codons. (2) Both of their Mt genome are highly preserved in terms of structural and functional genes, while the main variability is reflected in the length of tRNA, the number of genes, and the value of RSCU. (3) T. siniensis and T. ciliata were detected to have 94 and 87 SSRs, respectively, of which mononucleotides accounted for the absolute proportion. Besides, the vast majority of their SSRs were found to be poly-A or poly-T. (4)10 and 11 migrating fragments were identified in the comparison with the chloroplast genome, respectively. (5) In the ML evolutionary tree, T.sinensis and T.ciliata clustered individually into a small branch with 100% support, reflecting two species of Toona are very similarly related to each other. CONCLUSIONS: This research provides a basis for the exploitation of T.sinensis and T.ciliata in terms of medicinal, edible, and timber resources to avoid confusion; at the same time, it can explore the evolutionary relationship between the Toona and related species, which does not only have an important practical value, but also provides a theoretical basis for future hybrid breeding of forest trees, molecular markers, and evolutionary aspects of plants, which has great scientific significance.

Characterization of the 1-Deoxy-D-xylulose 5-Phosphate synthase Genes in Toona ciliata Suggests Their Role in Insect Defense.

The first enzyme, 1-Deoxy-D-xylulose-5-phosphate synthase (DXS), in the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway for isoprenoid precursor biosynthesis has been reported to function differently according to species. However, the current state of knowledge about this gene family in Toona ciliata is limited. The TcDXS gene family was identified from the whole genome of T. ciliata by firstly using bioinformatics analysis. Then, the phylogenetic tree was built and the promoter cis-elements were predicted. Six DXS genes were identified and divided into three groups, which had similar domains and gene structure. They are located on five different chromosomes and encode products that do not vary much in size. An analysis of the cis-acting elements revealed that TcDXS genes possessed light, abiotic stress, and hormone responsive elements. Ultimately, TcDXS1/2/5 was cloned for an in-depth analysis of their subcellular localization and expression patterns. The subcellular localization results of TcDXS1/2/5 showed that they were located in the chloroplast envelope membranes. Based on tissue-specific analyses, TcDXS1/2/5 had the highest expression in mature leaves. Under Hypsipyla robusta stress, their different expressions indicated that these genes may have insect-resistance functions. This research provides a theoretical basis for further functional verification of TcDXSs in the future, and a new concept for breeding pest-resistant T. ciliata.

Construction of a ratiometric fluorescent probe for visual detection of urea in human urine based on carbon dots prepared from Toona sinensis leaves and 5-carboxyfluorescein.

In this work, pH-sensitive blue fluorescent carbon dots (CDs) with high fluorescence quantum yield (17.24%) were synthesized by hydrothermal method using Toona sinensis leaves and ethylenediamine (EDA) as raw materials. The CDs can detect urea with a limit of detection (LOD) of 6.700 mmol L-1. For more sensitive detection of urea, we constructed a ratiometric fluorescent probe (CDs@5-FAM) using CDs and 5-carboxyfluorescein (5-FAM). The CDs@5-FAM probe can rapidly and sensitively detect urea according to the changes of I514/I405, with LOD as low as 0.014 mmol L-1. Furthermore, with the help of a smartphone and RGB analysis software, urea's visual intelligent detection was realized using a CDs@5-FAM probe. The method proposed in this paper is consistent with the standard method, which indicates that the pH-sensitive ratiometric fluorescent probe CDs@5-FAM is accurate and reliable for practical application. It provides a new way for rapid and visual detection of urea.

Preparation of Isoquercetin From Toona sinensis by Liquid-Liquid-Refining Extraction And Consecutive Counter-Current Chromatography.

A high-speed counter-current chromatographic (HSCCC) method using ethyl acetate-water as solvent system was established to separate isoquercetin from Toona sinensis. In an HSCCC single separation, the sample sizes of ethanol extract were optimized from 203 to 1200 mg. The results showed that the yield of the target compound increased from 4 to 26 mg, and the corresponding purity decreased from 93.30 to 81.82%. To further improve the yield and purity, liquid-liquid-refining extraction was introduced to pretreat the ethanol extract and enrich the target compound. The ethanol extract was extracted with n-hexane-ethyl acetate-method-water (1:5:1:5, v/v) and ethyl acetate-water in turn to remove the low-polarity and high-polarity impurities and obtain the crude sample. Under the similar conditions, 85.25 mg of the target compound with the purity of 95.12% was separated from 240 mg of the crude sample. Subsequently, a consecutive HSCCC was developed to obtain 257 mg of the target compound from 720 mg of crude sample, which was equivalent to 14.4 g of ethanol extract. This method improved the purity of the target compound, but more importantly, the sample size can reach 12 times of the maximum sample size of the ethanol extract in a single run.

Integrated volatilomic profiles and chemometrics provide new insights into the spatial distribution and aroma differences of volatile compounds in seven Toona sinensis cultivars.

As a popular vegetable, the unique and pleasant aroma is the key quality characteristic of Toona sinensis. To explore the sources and differences of aroma, the volatilomic profiling in the leaves and shoots of seven T. sinensis cultivars were investigated by chemometric analysis. The results indicated that aroma differences of each cultivar can be distinguished by W5S, W1S, W1W and W2S sensors during E-nose analysis. More than two thirds of all volatile organic compounds (VOCs) were derived from the leaves of most cultivars, except for Ximu toon. Notably, 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, 3,4-dimethyl thiophene, methyl thiirane, isocaryophyllene and hexanal were the major VOCs in both the leaves and shoots of T. sinensis. By constructing a weighted correlation network model, 5 modules and 11 hub VOCs were identified in the leaf samples of all cultivars. The data indicate that differential intracellular metabolic responses are responsible for the aroma formation of seven T. sinensis cultivars.

Brassinolide Soaking Reduced Nitrite Content and Extended Color Change and Storage Time of Toona sinensis Bud during Low Temperature and Near Freezing-Point Temperature Storage.

Low temperatures are often used to preserve fruits and vegetables. However, low-temperature storage also causes problems, such as chilling injury, nitrite accumulation, and browning aggravation in plants. This study investigated the effects of brassinolide (BR,1.0 mg L-1) solution soaking, storage temperatures (-2 ± 0.5 °C, 4 ± 0.5 °C, and 20 ± 1 °C), and their combinations on nitrite content, color change, and quality of stored Toona sinensis bud. The results showed that low temperature (LT, 4 ± 0.5 °C) and near freezing-point temperature (NFPT, -2 ± 0.5 °C) storage effectively inhibited the decay of T. sinensis bud compared to room temperature (20 ± 1 °C, the control). The combined treatments of BR with LT or NFPT reduced nitrite content and maintained the color and the contents of vitamin C, carotenoids, saponins, ß-sitosterol, polyphenol, anthocyanin, flavonoids, and alkaloids in T. sinensis bud. BR soaking delayed the occurrence of chilling injury during NFPT storage. Meanwhile, BR soaking enhanced the DPPH radical scavenging activity, ABTS activity, and FRAP content by increasing SOD and POD activity and the contents of proline, soluble, and glutathione, thus decreasing MDA and hydrogen peroxide content and the rate of superoxide radical production in T. sinensis bud during NFPT storage. This study provides a valuable strategy for postharvest T. sinensis bud in LT and NFPT storage. BR soaking extended the shelf life during LT storage and maintained a better appearance and nutritional quality during NFPT storage.

Evolutionary Divergence between Toona ciliata and Toona sinensis Assayed with Their Whole Genome Sequences.

Toona ciliata and Toona sinensis belong to the Toona genus of the Meliaceae family and are important timber species in China. T. ciliata is an endangered species at level II due to overcutting and a low rate of natural regeneration. T. sinensis was cultivated as an economic and nutritious tree for more than 2000 years. The two species differ in flower and leaf morphological traits, reproductive systems, and range size of natural distribution. To reveal the potential molecular basis of these divergences, we examined the similarities and differences in their whole genome sequences. Results indicate that T. ciliata had a higher number of expanded gene families than T. sinensis. The whole genome duplication (WGD) occurred before their speciation. The long-terminal repeats (LTRs) insertion was earlier in the T. ciliata genome (3.2985 ± 2.5007 Mya) than in the T. sinensis genome (3.1516 ± 2.2097 Mya). Twenty-five gene families in the T. ciliata genome were detected to be under positive selection compared with background branches of ten different land species. The T. ciliata genome was highly collinear with the T. sinensis genome, but had low collinearity with the genomes of more distant species. These genomic and evolutionary divergences are potentially associated with the differences between T. ciliata and T. sinensis in terms of their reproductive systems and ecological adaptation.

Membrane reactor based synthesis of biodiesel from Toona ciliata seed oil using barium oxide nano catalyst.

Membrane technology has been embraced as a feasible and promising substitute to the traditional technologies employed for biodiesel synthesis which are energy and time consuming. It needs less energy, has high stability, is environmentally friendly, and is simple to operate and control. Therefore, in our current study membrane technology was employed to synthesize biodiesel from Toona ciliate novel and non-edible seed oil. Since Toona ciliata has affluent oil content (33.8%) and is effortlessly and extensively available. In fact, we intended to scrutinize the effects of green synthesized barium oxide nanoparticles for one step transesterification of biodiesel production using membrane technology followed by characterization of prepared catalyst via innovative techniques. Optimal yield of biodiesel attained was 94% at 90 °C for 150 min with methanol to oil molar ratio of 9:1 and amount of about 0.39 wt %. Quantitative analysis of synthesized Toona ciliata oil biodiesel was carried out by advance techniques of Gas chromatography mass spectrometry (GC-MS), Fourier-transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR) which authorize the synthesis of fatty acid methyl ester compounds using oil from Toona ciliata seeds. Values of Toona ciliata fuel properties for instance flash point (70°C), density (0.89 kg/m3), viscosity (5.25 mm2/s), cloud point (-8°C) and pour point (-11°C) met the specifications of international standards i. e American (ASTM D-6751), European (EN-14214) and China (GB/T 20,828). Subsequently, it is concluded that membrane technology is environmentally friendly and efficient technique for mass-production of sustainable biodiesel using green nano catalyst of barium oxide.

Terpenoids from the Seeds of Toona sinensis and Their Ability to Attenuate High Glucose-Induced Oxidative Stress and Inflammation in Rat Glomerular Mesangial Cells.

Toona sinensis (A. Juss.) Roem is an edible medicinal plant that belongs to the genus Toona within the Meliaceae family. It has been confirmed to display a wide variety of biological activities. During our continuous search for active constituents from the seeds of T. sinensis, two new acyclic diterpenoids (1-2), together with five known limonoid-type triterpenoids (3-7), five known apotirucallane-type triterpenoids (8-12), and three known cycloartane-type triterpenoids (13-15), were isolated and characterized. Their structures were identified based on extensive spectroscopic experiments, including nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectra (HR-ESI-MS), and electronic circular dichroism (ECD), as well as the comparison with those reported in the literature. We compared these findings to those reported in the literature. Compounds 5, 8, and 13-14 were isolated from the genus Toona, and compounds 11 and 15 were obtained from T. sinensis for the first time. The antidiabetic nephropathy effects of isolated compounds against high glucose-induced oxidative stress and inflammation in rat glomerular mesangial cells (GMCs) were assessed in vitro. The results showed that new compounds 1 and 2 could significantly increase the levels of Nrf-2/HO-1 and reduce the levels of NF-κB, TNF-α, and IL-6 at concentrations of 30 µM. These results suggest that compounds 1 and 2 might prevent the occurrence and development of diabetic nephropathy (DN) and facilitate the research and development of new antioxidant and anti-inflammatory drugs suitable for the prevention and treatment of DN.

Identification of the novel natural product inhibitors of SHP2 from the plant Toona sinensis: In vitro and in silico study.

In this study, we tested the inhibitory activity of 45 natural products extracted from the plant Toona sinensis on SHP2 protein, and identified four natural product inhibitors. The natural product 1,2,3,6-Tetragalloylglucose (A-1) was first reported as a competitive inhibitor of SHP2, with an IC50 value of 0.20 ± 0.029 µM and the selectivity of 1.8-fold and 4.35-fold to high homologous proteins SHP1 and PTP1B, respectively. Compound A-1 also showed high inhibitory activity on SHP2-E76K and SHP2-E76A mutants, with IC50 values of 0.95 ± 0.21 µM and 0.29 ± 0.045 µM, respectively. Cell viability assay showed that compound A-1 could inhibit the proliferation of a variety of cancer cells. Apoptosis assay showed that compound A-1 could effectively induce apoptosis of KRASG12C-mut NCI-H23 and KRASG12S-mut A549 cells. Western blot assay showed that compound A-1 could down regulate the phosphorylation levels of Erk1/2 and Akt in NCI-H23 and A549 cells. Molecular docking showed that compound A-1 could effectively dock to the catalytic active region of SHP2. Molecular dynamics simulation explored the effect of compound A-1 on SHP2, revealing the deep-seated binding mechanism. This study would provide valuable clues for the development of SHP2 and its mutant inhibitors.

A Chromosome-Level Genome Assembly of Toona ciliata (Meliaceae).

Toona ciliata Roem is an important timber species in the Toona genus of the Meliaceae family and an endangered species due to over-cutting and a low rate of natural regeneration in China. Although molecular markers have been applied to studying population genetic diversity, the absence of a reliable reference genome limits in-depth genetic conservation and evolutionary studies of this species. Here, we reported a high-quality assembly of the whole genome sequence of T. ciliata. The total assembled genome has 520.64 Mb in length anchored on 28 chromosomes (contig N50 = 4.48 Mb). A total of 42,159 genes were predicted after the ab initio, homology-based, and transcriptome analyses. A total of 41,284 protein-encoding genes (97.92%) were functionally annotated and 1,246 non-coding RNAs were identified in the T. ciliata genome. Phylogenomic analysis showed that T. ciliata was divergent at 15.06 (6-25) Ma from T. sinensis of the same genus Toona. This whole genome sequence provides a valuable resource to study the genetic conservation and molecular evolution of T. ciliata in the future.

Inhibition of the P2X7/NLRP3 Inflammasome Signaling Pathway by Deacetylgedunin from Toona sinensis.

Limonoids are considered the effective part in Meliaceae plants that exert anti-inflammatory effects. Gedunin-type limonoids specifically have anti-inflammatory effects. However, the role of gedunin-type limonoids in the inflammatory diseases mediated by NLRP3 inflammasome remains to be explored. We found that deacetylgudunin (DAG), a gedunin-type limonoid from Toona sinensis, had similar anti-inflammatory effects and lower toxicity than gedunin. Further studies showed that DAG down-regulated the NF-κB pathway, inhibited K+ efflux and ROS release, inhibited ASC oligomerization, and significantly weakened the interaction of NLRP3 with ASC and NEK7. Furthermore, DAG could not further inhibit IL-1ß secretion and K+ efflux when combined with the P2X7 inhibitor A438079. In conclusion, our research revealed that DAG exerted an anti-inflammatory effect by inhibiting the P2X7/NLRP3 signaling pathway and enriched the application of gedunin-type limonoids in inflammatory diseases driven by the NLRP3 inflammasome.

Phylogeography of Toona ciliata (Meliaceae) Complex in China Inferred from Cytonuclear Markers.

Toona ciliata is an important timber species but is recognized as an endangered species at level II in China. Its genetic conservation is of increasing concern. Provenance trials and other breeding programs were conducted to develop seed transfer rules and multiplications. Here, we investigated twenty-nine populations sampled across the natural distribution of the T. ciliata complex using mtDNA and nrDNA ITS (ribosomal internal transcribed spacer) markers. Haplotype diversity was h = 0.190 ± 0.202 and nucleotide diversity was π = 0.000383 ± 0.000536 for mtDNA marker. Nucleotide diversity for ITS sequences was 0.00837 ± 0.000783. Haplotypes exhibited phylogeographic structure in spatial distribution. The extent of genetic differentiation was significant (Fst = 0.6994 ± 0.0079 for ITS and 0.8870 ± 0.0077 for mtDNA marker). Isolation by distance (IBD) and by elevation (IBE) occurred among populations. Phylogenetic relationships from mtDNA marker indicated three genetically distinct regions, each without IBD effects. Compared with pollen flow, seed flow was strongly impeded in the western region, but extensive in the central region, and less impeded in the eastern region. Most populations did not exhibit expansion, with only a few populations showing expansion after bottleneck effects. We discussed a strategy of region-based genetic conservation and proposed to conserve multiple populations in the western and eastern regions and a few populations in the central region.