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Camellia oleifera is a kind of high-quality oil supply species. Its seeds contain rich unsaturated fatty acids and antioxidant active ingredients, which is a kind of high-quality edible oil. In this study, we used bioinformatics methods to decipher a hexaploid Camellia oil tree’s mitochondrial (mt) genome based on second-generation sequencing data. A 709,596 bp circular map of C. oleifera mt genome was found for the first time. And 74 genes were annotated in the whole genome. Mt genomes of C. oleifera and three Theaceae species had regions with high similarity, including gene composition and gene sequence. At the same time, five conserved gene pairs were found in 20 species. In all of the mt genomes, most of nad genes existed in tandem pairs. In addition, the species classification result, which, according to the gene differences in tandem with nad5 genes, was consistent with the phylogenetic tree. These initial results provide a valuable basis for the further researches of Camellia oleifera and a reference for the systematic evolution of plant mt genomes.

Establishing a phototheranostic platform constructed by the second near-infrared (NIR-II) region has proved a revolutionary and promising strategy for cancer treatment. However, the antitumor effectiveness is severely limited by the monotonicity of the NIR-photothermal therapy (HPTT) modality and tumor thermotolerance caused by the production of heat shock proteins (HSPs). Here, a minimalistic approach is used to construct an organic nanoplatform (IFT@PEG-GOX NPs) with the reciprocal cyclic promotion of hypothermia and starvation treatments for NIR-II imaging-guided tumor therapy. After the enhanced permeability and retention (EPR) effect causes IFT@PEG-GOX NPs to accumulate in tumors, glucose oxidase (GOx)-mediated tumor starvation may obstruct the production of adenosine triphosphate (ATP) and downregulation heat shock proteins (HSPs), thereby reducing the thermotolerance of cells. After that, sensitized HPTT was activated and GOx's catalytic activity was increased by NIR laser irradiation. Then, there would be a subsequent, intensified inhibition of HSP along with an additional amplification of the GOx-mediated tumor starvation. As a consequence, the HPTT/Starvation therapy (ST) bidirectional cycle method is initiated, leading to a bidirectional cyclic enhancing impact of HPTT and ST and significantly better tumor suppression.

Abstract Orthotopic advanced hepatic tumor resection without precise location and preoperative downstaging may cause clinical postoperative recurrence and metastasis. Early accurate monitoring and tumor size reduction based on the multifunctional diagnostic-therapeutic integration platform could improve real-time imaging-guided resection efficacy. Here, a Near-Infrared II/Photoacoustic Imaging/Magnetic Resonance Imaging (NIR-II/PAI/MRI) organic nanoplatform IRFEP-FA-DOTA-Gd (IFDG) is developed for integrated diagnosis and treatment of orthotopic hepatic tumor. The IFDG is designed rationally based on the core “S-D-A-D-S” NIR-II probe IRFEP modified with folic acid (FA) for active tumor targeting and Gd-DOTA agent for MR imaging. The IFDG exhibits several advantages, including efficient tumor tissue accumulation, good tumor margin imaging effect, and excellent photothermal conversion effect. Therefore, the IFDG could realize accurate long-term monitoring and photothermal therapy non-invasively of the hepatic tumor to reduce its size. Next, the complete resection of the hepatic tumor in situ lesions could be realized by the intraoperative real-time NIR-II imaging guidance. Notably, the preoperative downstaging strategy is confirmed to lower the postoperative recurrence rate of the liver cancer patients under middle and advanced stage effectively with fewer side effects. Overall, the designed nanoplatform demonstrates great potential as a diagnostic-therapeutic integration platform for precise imaging-guided surgical navigation of orthotopic hepatic tumors with a low recurrence rate after surgery, providing a paradigm for diagnosing and treating the advanced tumors in the future clinical translation application. Graphical Abstract

Abstract Tumor microenvironment (TME)‐triggered phototheranostic platform offers a feasible strategy to improve cancer diagnosis accuracy and minimize treatment side effects. Developing a stable and biocompatible molecular phototheranostic platform for TME‐activated second near‐infrared (NIR‐II) fluorescence imaging‐guided multimodal cascade therapy is a promising strategy for creating desirable anticancer agents. Herein, a new NIR‐II fluorescence imaging‐guided activatable molecular phototheranostic platform (IR‐FEP‐RGD‐S‐S‐S‐Fc) is presented for actively targeted tumor imaging and hydrogen sulfide (H2S) gas‐enhanced chemodynamic‐hypothermal photothermal combined therapy (CDT/HPTT). It is revealed for the first time that the coupling distance between IR‐FE and ferrocene is proportional to the photoinduced electron transfer (PET), and the aqueous environment is favorable for PET generation. The part of Cyclic‐RGDfK (cRGDfk) peptides can target the tumor and benefit the endocytosis of nanoparticles. The high‐concentration glutathione (GSH) in the TME will separate the fluorescence molecule and ferrocene by the GSH‐sensitive trisulfide bond, realizing light‐up NIR‐II fluorescence imaging and a cascade of trimodal synergistic CDT/HPTT/gas therapy (GT). In addition, the accumulation of hydroxyl radicals (•OH) and down‐regulation of glutathione peroxidase 4 (GPX4) can produce excessive harmful lipid hydroperoxides, ultimately leading to ferroptosis.

Light is one of the most important environmental factors for plant growth. In the production process of tung oil tree cultivation, due to the inappropriate growth of shading conditions, the lower branches are often dry and dead, which seriously affects the yield of tung oil trees. However, little is known about the key factors of light-induced tree photomorphogenesis. In this study, a total of 22 VfBBX family members were identified to provide a reference for candidate genes in tung tree seedlings. All members of the VfBBX family have different numbers of highly conserved B-box domains or CCT domains. Phylogenetic evolution clustered the VfBBX genes into four categories, and the highest density of members was on chromosome 6. Interspecific collinearity analysis suggested that there were six pairs of duplicate genes in VfBBX members, but the expression levels of all family members in different growth and development stages of the tung tree were significantly divergent. After different degrees of shading treatment and physiological data determination of tung tree seedlings, the differential expression level and chlorophyll synthesis genes correlation analysis revealed that VfBBX9 was a typical candidate nuclear localization transcription factor that was significantly differentially expressed in light response. This study systematically identified the VfBBX gene family and provided a reference for studying its molecular function, enhanced the theoretical basis for tung tree breeding, and identified excellent varieties.

Abstract Phototherapy is a conducive and non-invasive strategy for cancer therapy under light irradiation. Inspiringly, fluorescence imaging in the second near-infrared window (NIR-II, 1000–1700 nm) holds a great promise for imaging-guided phototherapy with deep penetration and high spatiotemporal resolution. However, most phototherapeutics still face great challenges, including complicated synthesis of agents, potential biotoxicity and unsatisfied therapeutic outcomes. Herein, a near-infrared laser triggered molecular photosensitizer FEPT, modified with triphenylphosphine PEGylation (PEG2000-TPP), is developed for NIR-II imaging-guided mitochondria-targeting synergistic photothermal therapy (PTT)/photodynamic therapy (PDT)/immune therapy (IMT). The mitochondria-targeting photosensitizer FEPT can produce reactive oxygen species (ROS) and hyperpyrexia upon 808 nm laser irradiation, resulting in mitochondrial dysfunction and photo-induced apoptosis via caspase-3 pathway. Phototherapy-induced hyperthermia or ROS triggers the release of immunogenic intracellular substrates from dying tumor cells, thereby promoting the activation of antitumor immunity. Herein, this work provides a practicable strategy to develop a molecular phototheranostic platform for imaging-guided cancer therapy via mitochondria-targeting. Graphical Abstract

Camellia oleifera is a woody edible oil species with late self-incompatibility characteristics. Previous transcriptome analysis showed that genes involved in jasmonic acid signal transduction were significantly different in self-and cross-pollinated pistils of Camellia oleifera. To investigate the relationship between jasmonate signal and self-incompatibility by studying the core genes of jasmonate signal transduction. The results showed that exogenous JA and MeJA at 1.0 mM significantly inhibited pollen tube germination and pollen tube elongation. and JA up-regulated CoCOI1, CoJAZ1, and CoMYC, the core genes of jasmonate signal transduction. Subcellular localization indicated that CoCOI1 and CoJAZ1 were located in the nucleus and CoMYC2 in the endoplasmic reticulum. The three genes exhibited tissue-specific expression pattern. CoCOI1 was significantly expressed in pollen, CoJAZ1 was significantly expressed in ovary, CoMYC2 was significantly expressed in filaments, but not in pollen. Furthermore, CoJAZ1 and CoMYC2 were highly expressing at 24 h in self-pollinated styles. These results suggested that JA signal transduction of C. oleifera was involved in the process of self-pollination, and thus in the process of plant defense. When pollen tubes grew slowly in the style, ovary may receive JA signal, which initiates the molecular mechanism of inhibiting the growth of self-pollinating pollen tubes.

Abstract Background Camellia oleifera Abel. (C. oleifera) is an important traditional woody species in China that produces edible oil. However, the current literature lacks a proper understanding of C. oleifera’s ability to adapt to different photoperiods. Results Our results indicate that the photoperiod can significantly impact flowering time in C. oleifera. We grew a total of nine samples under the short day condition (SD), middle day condition (MD) and long day condition (LD). Transcriptome analysis yielded 66.94 Gb of high-quality clean reads, with an average of over 6.73 Gb of reads for per sample. Following assembly, a total of 120,080 transcripts were obtained and 94,979 unigenes annotated. A total of 3475 differentially expressed genes (DEGs) were identified between the SD_MD, SD_LD, and MD_LD gene sets. Moreover, WGCNA identified ten gene modules. Genes in pink module (92 genes) were positively correlated with SD, and negatively correlated with both MD and LD. Genes in the magenta module (42 genes) were positively correlated with MD and negatively correlated with both LD and SD. Finally, genes in the yellow module (1758 genes) were positively correlated with both SD and MD, but negatively correlated with LD. KEGG enrichment analysis revealed that genes in the pink, magenta, and yellow modules were involved in flavonoid biosynthesis, amino sugar and nucleotide sugar metabolism and circadian rhythm pathways. Additionally, eight hub genes (GI, AP2, WRKY65, SCR, SHR, PHR1, ERF106, and SCL3) were obtained through network analysis. The hub genes had high connectivity with other photoperiod-sensitive DEGs. The expression levels of hub genes were verified by qRT-PCR analysis. Conclusion An increase in light duration promotes earlier flowering of C. oleifera. Flavonoid biosynthesis, amino sugar and nucleotide sugar metabolism, and circadian rhythm pathways may function in the photoperiodic flowering pathway of C. oleifera. We also identified eight hub genes that may play a role in this pathway. Ultimately, this work contributes to our understanding of the photoperiodic flowering pathway of C. oleifera and further informs molecular breeding programs on the plant’s photoperiodic sensitivity.

IntroductionSelf-incompatibility (SI) is an important strategy for plants to maintain abundant variation to enhance their adaptability to the environment. Camellia oleifera is one of the most important woody oil plants and is widely cultivated in China. Late acting self-incompatibility (LSI) in C. oleifera results in a relatively poor fruit yield in the natural state, and understanding of the LSI mechanism remains limited. MethodsTo better understand the molecular expression and gene coexpression network in the LSI reaction in C. oleifera, we conducted self- and cross-pollination experiments at two different flower bud developmental stages (3–4 d before flowering and 1 d before flowering), and cytological observation, fruit setting rate (FSR) investigation and RNA-Seq analysis were performed to investigate the mechanism of the male −female interaction and identify hub genes responsible for the LSI in C. oleifera.ResultsBased on the 21 ovary transcriptomes, a total of 7669 DEGs were identified after filtering out low-expression genes. Weighted gene coexpression network analysis (WGCNA) divided the DEGs into 15 modules. Genes in the blue module (1163 genes) were positively correlated with FSR, and genes in the pink module (339 genes) were negatively correlated with FSR. KEGG analysis indicated that flavonoid biosynthesis, plant MAPK signaling pathways, ubiquitin-mediated proteolysis, and plant-pathogen interaction were the crucial pathways for the LSI reaction. Fifty four transcription factors (TFs) were obtained in the two key modules, and WRKY and MYB were potentially involved in the LSI reaction in C. oleifera. Network establishment indicated that genes encoding G-type lectin S-receptor-like serine (lecRLK), isoflavone 3’-hydroxylase-like (CYP81Q32), cytochrome P450 87A3-like (CYP87A3), and probable calcium-binding protein (CML41) were the hub genes that positively responded to the LSI reaction. The other DEGs inside the two modules, including protein RALF-like 10 (RALF), F-box and pectin acetylesterase (MTERF5), might also play vital roles in the LSI reaction in C. oleifera.DiscussionOverall, our study provides a meaningful resource for gene network studies of the LSI reaction process and subsequent analyses of pollen−pistil interactions and TF roles in the LSI reaction, and it also provides new insights for exploring the mechanisms of the LSI response.

Introduction: Evolution of organic light-emitting diodes (OLEDs) reached the point, which allows to obtain maximum internal quantum efficiency of 100% partly using heavy-metal-free emitters exhibiting thermally activated delayed fluorescence (TADF). Such emitters are also predictively perfect candidates for new generation of optical sensors since triplet harvesting can be sensitive to different analytes (at least to oxygen). Although many organic TADF emitters have been reported so far as OLED emitters, the investigation of materials suitable for both OLEDs and optical sensors remains extremely rare. Objectives: Aiming to achieve high photoluminescence quantum yields in solid-state and triplet harvesting abilities of organic semiconductors with efficient bipolar charge transport required for application in both blue OLEDs and optical sensors, symmetrical donor–acceptor-donor organic emitters containing pyrimidine-5-carbonitrile electron-withdrawing scaffold and carbazole, tert-butylcarbazole and methoxy carbazole donor moieties were designed, synthesized and investigated as the main objectives of this study. Methods: New compounds were tested by many experimental methods including optical and photoelectron spectroscopy, time of flight technique, electrochemistry and thermal analyses. Results: Demonstrating advantages of the molecular design, the synthesized emitters exhibited sky-blue efficient TADF with reverse intersystem crossing rates exceeding 106 s−1, aggregation-induced emission enhancement with photoluminescence quantum yields in solid state exceeding 50%, hole and electron transporting properties with charge mobilities exceeding 10-4 cm2/V·s, glass-forming properties with glass transition temperatures reaching 177 °C. Sky-blue OLEDs with non-doped light-emitting layers of the synthesized emitter showed maximum external efficiency of 12.8% while the doped device with the same emitter exhibited maximum external efficiency of 14%. The synthesized emitters were also used as oxygen probes for optical sensors with oxygen sensitivity estimated by the Stern-Volmer constant of 3.24·10-5 ppm−1. Conclusion: The developed bipolar TADF emitters with pyrimidine-5-carbonitrile and carbazole moieties showed effective applicability in both blue OLEDs and optical sensors.

Abstract Background The oil-tea tree (Camellia oleifera Abel.) is a woody tree species that produces edible oil in the seed. C. oleifera oil has high nutritional value and is also an important raw material for medicine and cosmetics. In China, due to the uncertainty on maturity period and oil synthesis mechanism of many C. oleifera cultivars, growers may harvest fruits prematurely, which could not maximize fruit and oil yields. In this study, our objective was to explore the mechanism and differences of oil synthesis between two Camellia oleifera cultivars for a precise definition of the fruit ripening period and the selection of appropriate cultivars. Results The results showed that ‘Huashuo’ had smaller fruits and seeds, lower dry seed weight and lower expression levels of fatty acid biosynthesis genes in July. We could not detect the presence of oil and oil bodies in ‘Huashuo’ seeds until August, and oil and oil bodies were detected in ‘Huajin’ seeds in July. Moreover, ‘Huashuo’ seeds were not completely blackened in October with up to 60.38% of water and approximately 37.98% of oil in seed kernels whose oil content was much lower than normal mature seed kernels. The oil bodies in seed endosperm cells of ‘Huajin’ were always higher than those of ‘Huashuo’ from July to October. Conclusion Our results confirmed that C. oleifera ‘Huashuo’ fruits matured at a lower rate compared to ‘Huajin’ fruits and that ‘Huajin’ seeds entered the oil synthesis period earlier than ‘Huashuo’ seeds. Moreover, ‘Huashuo’ fruits did not mature during the Frost’s Descent period (October 23–24 each year).

The Camellia oil tree (Camellia oleifera Abel.) is an important nonwood forest species in China, and the majority of its cultivars are late-acting self-incompatibility (LSI) types. Although several studies have examined the mechanism of LSI, the process is quite complicated and unclear. In this study, pollen tube growth and fruit setting of two Camellia oil tree cultivars Huashuo (HS) and Huajin (HJ) were investigated after non and self-pollination, and transcriptomic analysis of the ovaries was performed 48 h after self-pollination to identify the potential genes implicated in the LSI of Camellia oil trees. The results showed that the fruit set of HS was significantly higher than that of HJ after self-pollination. Transcriptomic analysis revealed that plant hormone signal transduction, the phosphatidylinositol signaling system, ATP-binding cassette (ABC) transporters, reactive oxygen species (ROS) metabolism, and Ca2+ signaling were mainly contributed in the LSI of reaction of Camellia oil tree. Moreover, nine RNase T2 genes were identified from the transcriptome analysis, which also showed that CoRNase7 participated in the self-incompatibility reaction in HS. Based on phylogenetic analysis, CoRNase6 was closely related to S-RNase from coffee, and CoRNase7 and CoRNase8 were closely related to S-RNase from Camellia sinensis. The 9 RNase T2 genes successfully produced proteins in prokaryotes. Subcellular localization indicated that CoRNase1 and CoRNase5 were cytoplasmic proteins, while CoRNase7 was a plasma membrane protein. These results screened the main metabolic pathways closely related to LSI in Camellia oil tree, and SI signal transduction might be regulated by a large molecular regulatory network. The discovery of T2 RNases provided evidence that Camellia oil tree might be under RNase-based gametophytic self-incompatibility.

In recent years, pathogenic infections have been a growing health threat due to the proliferation of drug-resistant bacteria, so photothermal therapy (PTT) has gained considerable interest in biological and medical fields, owing to its noninvasive and highly effective properties. However, it is hard to achieve selective bacteria targeting while generating a large amount of heat at infected sites. Cationic electrostatic interaction is considered to be a common antimicrobial strategy. Herein, an organic molecule named RT-MN was synthesized with four positively charged quaternary ammonium salts that can bind to negatively charged bacteria. Under near-infrared 808 nm laser irradiation, RT-MN could be efficiently converted into a large amount of heat to eradicate bacteria. In addition, its good water solubility and biological safety proved that RT-MN has excellent biological application prospects. Overall, four such positively charged photosensitizer RT-MN, as a non-antibiotic treatment for resistant bacteria, could be promising for the exploration of highly effective antibacterial agents.

The Sorting and Assembly Machinery (SAM) complex folds beta-barrel proteins and inserts them into the mitochondrial outer membrane. Here authors report cryoEM structures of the SAM complex from Myceliophthora thermophila, which reveals a GST-like fold for Sam35 and Sam37 and sheds light on how the Sam50 beta-barrel opens a lateral gate to accommodate its substrates.

Tung tree (Vernicia fordii) is an economically important woody oil plant that produces tung oil rich in eleostearic acid. Here, we report a high-quality chromosome-scale genome sequence of tung tree. The genome sequence was assembled by combining Illumina short reads, Pacific Biosciences single-molecule real-time long reads, and Hi-C sequencing data. The size of tung tree genome is 1.12 Gb, with 28,422 predicted genes and over 73% repeat sequences. The V. fordii underwent an ancient genome triplication event shared by core eudicots but no further whole-genome duplication in the subsequent ca. 34.55 million years of evolutionary history of the tung tree lineage. Insertion time analysis revealed that repeat-driven genome expansion might have arisen as a result of long-standing long terminal repeat retrotransposon bursts and lack of efficient DNA deletion mechanisms. The genome harbors 88 resistance genes encoding nucleotide-binding sites; 17 of these genes may be involved in early-infection stage of Fusarium wilt resistance. Further, 651 oil-related genes were identified, 88 of which are predicted to be directly involved in tung oil biosynthesis. Relatively few phosphoenolpyruvate carboxykinase genes, and synergistic effects between transcription factors and oil biosynthesis-related genes might contribute to the high oil content of tung seed. The tung tree genome constitutes a valuable resource for understanding genome evolution, as well as for molecular breeding and genetic improvements for oil production.

Near-Infrared-II (NIR-II) bioimaging is a newly emerging visualization modality in real-time investigations of biological processes research. Owning to advances in reducing photon scattering and low tissue autofluorescence levels in NIR-II region (1,000–1700 nm), NIR-II bioimaging affords high resolution with increasing tissue penetration depth, and it shows greater application potential for in vivo detection to obtain more detailed qualitative and quantitative parameters. Herein, this review summarizes recent progresses made on NIR-II bioimaging for quantitative analysis. These emergences of various NIR-II fluorescence, photoacoustic (PA), luminescence lifetime imaging probes and their quantitative analysis applications are comprehensively discussed, and perspectives on potential challenges facing in this direction are also raised.

Theasaponin derivatives, which are reported to exert antitumor activity, have been widely reported to exist in edible plants, including in the seed cake of Camellia oleifera (C.), which is extensively grown in south of China. The purpose of this study was to isolate new theasaponin derivatives from C. seed cake and explore their potential antitumor activity and their underlying molecular mechanism. In the present study, we first isolated and identified four theasaponin derivatives (compounds 1, 2, 3, and 4) from the total aglycone extract of the seed cake of Camellia oleifera by utilizing a combination of pre-acid-hydrolysis treatment and activity-guided isolation. Among them, compound 1 (C1) and compound 4 (C4) are newly discovered theasaponins that have not been reported before. The structures of these two new compounds were characterized based on comprehensive 1D and 2D NMR spectroscopy and high-resolution mass spectrometry, as well as data reported in the literature. Secondly, the cytotoxicity and antitumor property of the above four purified compounds were evaluated in selected typical tumor cell lines, Huh-7, HepG2, Hela, A549, and SGC7901, and the results showed that the ED50 value of C4 ranges from 1.5 to 11.3 µM, which is comparable to that of cisplatinum (CDDP) in these five cell lines, indicating that C4 has the most powerful antitumor activity among them. Finally, a preliminary mechanistic investigation was performed to uncover the molecular mechanism underlying the antitumor property of C4, and the results suggested that C4 may trigger apoptosis through the Bcl-2/Caspase-3 and JAK2/STAT3 pathways, and stimulate cell proliferation via the NF-κB/iNOS/COX-2 pathway. Moreover, it was surprising to find that C4 can inhibit the Nrf2/HO-1 pathway, which indicates that C4 has the potency to overcome the resistance to cancer drugs. Therefore, C1 and C4 are two newly identified theasaponin derivatives with antitumor activity from the seed cake of Camellia oleifera, and C4 is a promising antitumor candidate not only for its powerful antitumor activity, but also for its ability to function as an Nrf2 inhibitor to enhance the anticancer drug sensitivity.

Performance of the powerful discriminative random field (DRF) model for image processing and analysis is easily affected by the inherent speckle noise and the time-consuming iteration. Therefore, in this paper, a superpixel-based hybrid DRF (sp-HDRF) model is proposed for fast polarimetric synthetic aperture radar (PolSAR) image classification. The sp-HDRF model realizes the classification by two steps. First, the simple linear iterative clustering algorithm, which is modified by introducing the ratio of exponentially weighted averages operator, is utilized to obtain a superpixel graph with more accurate edge locations. Second, the conditional posterior distribution and the inference formula of the sp-HDRF model are derived on the superpixel graph, which is a generalization of a DRF model on the pixel. Then, the sp-HDRF model is applied to implement classification. Finally, the sp-HDRF model has the fusion of the polarimetric scattering features, the statistics, and the spatial relationships of the image. The experimental results on the real PolSAR images demonstrate the effectiveness of the sp-HDRF model and illustrate that it can provide stronger noise immunity, obtain smoother homogeneous areas in classification, and enhance the computational efficiency simultaneously.

Camellia oleifera is an economically important oilseed tree. Seed meals of C. oleifera have a long history of use as biocontrol agents in shrimp farming and as cleaning agents in peoples’ daily lives due to the presence of theasaponins, the triterpene saponins from the genus Camellia. To characterize the biosynthetic pathway of theasaponins in C. oleifera, members of gene families involved in triterpenoid biosynthetic pathways were identified and subjected to phylogenetic analysis with corresponding members in Arabidopsis thaliana, Camellia sinensis, Actinidia chinensis, Panax ginseng, and Medicago truncatula. In total, 143 triterpenoid backbone biosynthetic genes, 1169 CYP450s, and 1019 UGTs were identified in C. oleifera. The expression profiles of triterpenoid backbone biosynthetic genes were analyzed in different tissue and seed developmental stages of C. oleifera. The results suggested that MVA is the main pathway for triterpenoid backbone biosynthesis. Moreover, the candidate genes for theasaponin biosynthesis were identified by WGCNA and qRT-PCR analysis; these included 11 CYP450s, 14 UGTs, and eight transcription factors. Our results provide valuable information for further research investigating the biosynthetic and regulatory network of theasaponins.

Background/Aims: Psoralen and bakuchiol are the main active compounds found in the traditional Chinese medicine Psoralea corylifolia L., and have been used to treat osteoporosis. This study aims to investigate the anti-osteoporosis effects of these two compounds using osteoclasts precursor differentiation and bone absorption assays in vitro. Methods: Primary mouse osteoclasts precursor cells were induced by M-CSF (macrophage colony stimulating factor) plus RANKL (receptor activator of nuclear factor kappa-B ligand) in vitro. TRACP (tartrate-resistant acid phosphatase) enzyme activity and toluidine blue staining were used to observe the effects of psoralen and bakuchiol on osteoclast differentiation and bone resorption, respectively. Gelatin zymography was used to assess MMP (matrix metalloproteinase) activity, and ELISA was performed to measure cathepsin K activity. Western blotting analysis for expression of phosphorylated AKT, ERK, NF-kB, and c-jun; and immunofluorescence analysis for c-jun and p65 nuclear translocation in induced osteoclasts were then used to determine the mechanism of anti-bone resorption of psoralen and bakuchiol. Results: Mature osteoclasts were induced by M-CSF plus RANKL from primary bone marrow macrophages in vitro. Both psoralen and bakuchiol significantly inhibited TRACP enzyme activity and slightly decreased the number of TRACP+ multinuclear osteoclasts induced by M-CSF plus RANKL. Bakuchiol significantly decreased bone lacunae area and attenuated MMP-2 activity induced by M-CSF plus RANKL in osteoclasts. Both psoralen and bakuchiol significantly decreased the expression and nuclear translocation of phosphorylated c-jun stimulated by M-CSF plus RANKL, but no significant effect on p65 translocation was observed in osteoclasts. Additionally, bakuchiol significantly attenuated the increased of M-CSF plus RANKL-induced phosphorylation of AKT in osteoclasts. Conclusions: Psoralen and bakuchiol ameliorated M-CSF plus RANKL-induced osteoclast differentiation and bone resorption via inhibition of AKT and AP-1 pathways activation in vitro.

Tea green leafhopper (Empoasca onukii Matsuda) is a critical pest in tea production. Wolbachia has attracted much attention as a new direction of pest biological control for its ability of manipulating the hosts’ reproductive biology. In this work, we focused on the detection of Wolbachia in tea green leafhopper and its effect on host reproduction and development. Polymerase chain reaction (PCR), real-time PCR, and fluorescence in situ hybridization (FISH) techniques were used to detect the distribution of Wolbachia in tea green leafhopper. Wolbachia infection levels were different in different organs of hosts in different insect stages. In addition, comparison between the infected populations and cured population (treated by tetracyclines) revealed that presence of Wolbachia apparently influenced the growth, life cycle, and other reproductive factors of tea green leafhopper, caused, for example, by cytoplasmic incompatibility (CI), thereby reducing number of offspring, shortening lifespan, and causing female-biased sex ratio. This research confirmed that the bacteria Wolbachia was of high incidence in tea leafhoppers and could significantly affect the hosts’ reproductive development and evolution.

Abstract Tung tree (Vernicia fordii) is an economically important tree widely cultivated for industrial oil production in China. To better understand the molecular basis of tung tree chloroplasts, we sequenced and characterized its genome using PacBio RS II sequencing platforms. The chloroplast genome was sequenced with 161,528 bp in length, composed with one pair of inverted repeats (IRs) of 26,819 bp, which were separated by one small single copy (SSC; 18,758 bp) and one large single copy (LSC; 89,132 bp). The genome contains 114 genes, coding for 81 protein, four ribosomal RNAs and 29 transfer RNAs. An expansion with integration of an additional rps19 gene in the IR regions was identified. Compared to the chloroplast genome of Jatropha curcas, a species from the same family, the tung tree chloroplast genome is distinct with 85 single nucleotide polymorphisms (SNPs) and 82 indels. Phylogenetic analysis suggests that V. fordii is a sister species with J. curcas within the Eurosids I. The nucleotide sequence provides vital molecular information for understanding the biology of this important oil tree.

Tung tree (Vernicia fordii), an economically important woody oil plant, is a monoecious and diclinous species with male and female flowers on the same inflorescence. The extremely low proportion of female flowers leads to low fruit yield in tung orchards. The female flower normally develops along with stamen abortion; otherwise sterile ovules will be produced. However, little knowledge is known about the molecular basis of the female flower development in tung tree. In this study, integrated analyses of morphological and cytological observations, endogenous phytohormone assay and RNA-seq were conducted to understand the molecular mechanism of the female flower development in tung tree. Cytological observation suggested that the abortion of stamens in female flowers (SFFs) belongs to the type of programmed cell death (PCD), which was caused by tapetum degeneration at microspore mother cell stage. A total of 1,366 differentially expressed genes (DEGs) were identified in female flowers by RNA-seq analysis, of which 279 (20.42%) DEGs were significantly enriched in phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Stage-specific transcript identification detected dynamically expressed genes of important transcription regulators in female flowers that may be involved in PCD and floral organ development. Gene expression patterns revealed that 17 anther and pollen development genes and 37 PCD-related genes might be involved in the abortion of SFF. Further analyses of phytohormone levels and co-expression networks suggested that salicylic acid (SA) accumulation could trigger PCD and inhibit the development of SFF in tung tree. This study provides new insights into the role of SA in regulating the abortion of SFF to develop normal female flowers.

Oil-tea tree (Camellia oleifera) is the most important edible oil tree species in China with late-acting self-incompatibility (LSI) properties. The mechanism of LSI is uncertain, which seriously hinders the research on its genetic characteristics, construction of genetic map, selection of cross breeding parents and cultivar arrangement. To gain insights into the LSI mechanism, we performed cytological, transcriptomic, proteomic and metabolomic studies on self- and cross-pollinated pistils. The studies identified 166,591 transcripts, 6851 proteins and 6455 metabolites. Transcriptomic analysis revealed 1197 differentially expressed transcripts between self- and cross-pollinated pistils and 47 programmed cell death (PCD)-control transcripts. Trend analysis by Pearson correlation categorized nine trend graphs linked to 226 differentially expressed proteins and 38 differentially expressed metabolites. Functional enrichment analysis revealed that the LSI was closely associated with PCD-related genes, mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signal transduction, ATP-binding cassette (ABC) transporters and ubiquitin-mediated proteolysis. These particular trends in transcripts, proteins and metabolites suggested the involvement of PCD in LSI. The results provide a solid genetic foundation for elucidating the regulatory network of PCD-mediated self-incompatibility in C. oleifera.

‘Huaxin’ is a new high-yielding timber cultivar of Camellia oleifera of high economic value, and has been widely cultivated in the red soil hilly region of Hunan Province of the People´s Republic of China in recent years. However, its quality and production are severely affected by low temperatures during flowering. To find genes related to cold tolerance and further explore new candidategenes for chilling-tolerance, Illumina NGS (Next Generation Sequencing) technology was used to perform transcriptomic analyses of C. oleifera ‘Huaxin’ leaves under long-term cold stress. Nine cDNA libraries were sequenced, and 58.31 Gb high-quality clean reads were obtained with an average of 5.92 Gb reads for each sample. A total of 191,150 transcripts were obtained after assembly. Among them, 100,703 unigenes were generated, and 44,610 unigenes were annotated. In total, 1564 differentially expressed genes (DEGs) were identified both in the A_B and A_C gene sets. In the current study, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, andrevealed a group of cold-responsive genes related to hormone regulation, photosynthesis, membrane systems, and osmoregulation; these genes encoded many key proteins in plant biological processes, such as serine/threonine-protein kinase (STPK), transcription factors (TFs), fatty acid desaturase (FAD), lipid-transfer proteins (LTPs), soluble sugars synthetases, and flavonoid biosynthetic enzymes. Some physiological indicators of C. oleifera ‘Huaxin’ were determined under three temperature conditions, and the results were consistent with the molecular sequencing. In addition, the expression levels of 12 DEGs were verified using quantitative real-time polymerase chain reaction (qRT-PCR). In summary, the results of DEGs analysis together with qRT-PCR tests contribute to the understanding of cold tolerance and further exploring new candidate genes for chilling-tolerance in molecular breeding programs of C. oleifera ‘Huaxin’.

Tung tree (Vernicia fordii) is one of the important oil plants in China. The current researches on tung tree are mainly focused on the cultivation and breeding while the molecular mechanisms hidden in the back of tung tree's phenotypes are still uncovered. This research compared the transcriptome of three different stages during tung tree's seed development using RNA-Seq and obtained a lot of differentially expressed Unigenes. Through GO classification and pathway enrichment analysis, all of these differentially expressed Unigenes were classified into 128 signaling pathways including fatty acid biosynthesis. Fourteen homologous proteins were obtained when the sequences of 54 Unigenes within fatty acid biosynthesis pathway were aligned against KEGG database and the expression profiles of the genes encoding these proteins during seed development were analyzed. This research provides necessary data platform to elucidate the molecular mechanism underlies fatty acid biosynthesis of tung tree's seeds and theoretical guidance of tung tree varieties' improvement to increase output of tung oil.

Diospyros is the largest genus in Ebenaceae, comprising more than 500 species with remarkable economic value, especially Diospyros kaki Thunb., which has traditionally been an important food resource in China, Korea, and Japan. Complete chloroplast (cp) genomes from D. kaki, D. lotus L., D. oleifera Cheng., D. glaucifolia Metc., and Diospyros 'Jinzaoshi' were sequenced using Illumina sequencing technology. This is the first cp genome reported in Ebenaceae. The cp genome sequences of Diospyros ranged from 157,300 to 157,784 bp in length, presenting a typical quadripartite structure with two inverted repeats each separated by one large and one small single-copy region. For each cp genome, 134 genes were annotated, including 80 protein-coding, 31 tRNA, and 4 rRNA unique genes. In all, 179 repeats and 283 single sequence repeats were identified. Four hypervariable regions, namely, intergenic region of trnQ_rps16, trnV_ndhC, and psbD_trnT, and intron of ndhA, were identified in the Diospyros genomes. Phylogenetic analyses based on the whole cp genome, protein-coding, and intergenic and intron sequences indicated that D. oleifera is closely related to D. kaki and could be used as a model plant for future research on D. kaki; to our knowledge, this is proposed for the first time. Further, these analyses together with two large deletions (301 and 140 bp) in the cp genome of D. 'Jinzaoshi', support its placement as a new species in Diospyros. Both maximum parsimony and likelihood analyses for 19 taxa indicated the basal position of Ericales in asterids and suggested that Ebenaceae is monophyletic in Ericales.

Triacylglycerols (TAG) are the major molecules of energy storage in eukaryotes. TAG are packed in subcellular structures called oil bodies or lipid droplets. Oleosins (OLE) are the major proteins in plant oil bodies. Multiple isoforms of OLE are present in plants such as tung tree (Vernicia fordii), whose seeds are rich in novel TAG with a wide range of industrial applications. The objectives of this study were to identify OLE genes, classify OLE proteins and analyze OLE gene expression in tung trees. We identified five tung tree OLE genes coding for small hydrophobic proteins. Genome-wide phylogenetic analysis and multiple sequence alignment demonstrated that the five tung OLE genes represented the five OLE subfamilies and all contained the "proline knot" motif (PX5SPX3P) shared among 65 OLE from 19 tree species, including the sequenced genomes of Prunus persica (peach), Populus trichocarpa (poplar), Ricinus communis (castor bean), Theobroma cacao (cacao) and Vitis vinifera (grapevine). Tung OLE1, OLE2 and OLE3 belong to the S type and OLE4 and OLE5 belong to the SM type of Arabidopsis OLE. TaqMan and SYBR Green qPCR methods were used to study the differential expression of OLE genes in tung tree tissues. Expression results demonstrated that 1) All five OLE genes were expressed in developing tung seeds, leaves and flowers; 2) OLE mRNA levels were much higher in seeds than leaves or flowers; 3) OLE1, OLE2 and OLE3 genes were expressed in tung seeds at much higher levels than OLE4 and OLE5 genes; 4) OLE mRNA levels rapidly increased during seed development; and 5) OLE gene expression was well-coordinated with tung oil accumulation in the seeds. These results suggest that tung OLE genes 1-3 probably play major roles in tung oil accumulation and/or oil body development. Therefore, they might be preferred targets for tung oil engineering in transgenic plants.

Tung tree (Vernicia fordii) provides the sole source of tung oil widely used in industry. Lack of fatty acid composition and molecular markers hinders biochemical, genetic and breeding research. The objectives of this study were to determine fatty acid profiles and develop unigene-derived simple sequence repeat (SSR) markers in tung tree. Fatty acid profiles of 41 accessions showed that the ratio of α-eleostearic acid was increasing continuously with a parallel trend to the amount of tung oil accumulation while the ratios of other fatty acids were decreasing in different stages of the seeds and that α-eleostearic acid (18∶3) consisted of 77% of the total fatty acids in tung oil. Transcriptome sequencing identified 81,805 unigenes from tung cDNA library constructed using seed mRNA and discovered 6,366 SSRs in 5,404 unigenes. The di- and tri-nucleotide microsatellites accounted for 92% of the SSRs with AG/CT and AAG/CTT being the most abundant SSR motifs. Fifteen polymorphic genic-SSR markers were developed from 98 unigene loci tested in 41 cultivated tung accessions by agarose gel and capillary electrophoresis. Genbank database search identified 10 of them putatively coding for functional proteins. Quantitative PCR demonstrated that all 15 polymorphic SSR-associated unigenes were expressed in tung seeds and some of them were highly correlated with oil composition in the seeds. Dendrogram revealed that most of the 41 accessions were clustered according to the geographic region. These new polymorphic genic-SSR markers will facilitate future studies on genetic diversity, molecular fingerprinting, comparative genomics and genetic mapping in tung tree. The lipid profiles in the seeds of 41 tung accessions will be valuable for biochemical and breeding studies.

Many flowering plants exhibit an important intraspecific reproductive barrier phenomenon, that is, self-incompatibility (SI), in which S-RNase genes play a significant role. To clarify the specific function of S-RNase genes in Chinese pears, the full length cDNA of PbS26-RNase was isolated by rapid amplification of cDNA ends (RACE) technology from Chinese white pear (Pyrus bretschneideri) cultivar “Hongpisu.” The cDNA sequence for PbS26-RNase was deposited in GenBank under accession number EU081888. At the amino acid level, the PbS26-RNase displayed the highest similarity (96.9%) with PcSa-RNase of P. communis, and only seven amino acid differences were present in the two S-RNases. Phylogenetic analysis of rosaceous S-RNases indicated that the PbS26-RNase clustered with maloideous S-RNases, forming a subfamily-specific not a species-specific group. The PbS26-RNase gene was specifically expressed in the style but not other tissues/organs. The expression level of the PbS26-RNase gene rapidly increased at bell balloon stage (BBS), and then it dropped after pollination. However, the abundance of the PbS26-RNase gene transcript in the style was greater after cross-pollination than after self-pollination. In addition, a method for rapidly detecting the PbS26-RNase gene was developed via allele-specific primers design. The present study could provide a scientific basis for fully clarifying the mechanism of pear SI at the molecular level.

Tea oil tree (Camellia oleifera, Co) provides a fine edible oil source in China. Tea oil from the seeds is very beneficial to human health. Fructose-1,6-bisphosphate aldolase (FBA) hydrolyzes fructose-1,6-bisphosphate into dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, two critical metabolites for oil biosynthesis. The objectives of this study were to identify FBA genes and investigate the relationship between FBA gene expression and oil content in developing seeds of tea oil tree. In this paper, four developmentally up-regulated CoFBA genes were identified in Camellia oleifera seeds based on the transcriptome from two seed developmental stages corresponding to the initiation and peak stages of lipid biosynthesis. The expression of CoFBA genes, along with three key oil biosynthesis genes CoACP, CoFAD2 and CoSAD were analyzed in seeds from eight developmental stages by real-time quantitative PCR. The oil content and fatty acid composition were also analyzed. The results showed that CoFBA and CoSAD mRNA levels were well-correlated with oil content whereas CoFAD2 gene expression levels were correlated with fatty acid composition in Camellia seeds. We propose that CoFBA and CoSAD are two important factors for determining tea oil yield because CoFBA gene controls the flux of key intermediates for oil biosynthesis and CoSAD gene controls the synthesis of oleic acid, which accounts for 80% of fatty acids in tea oil. These findings suggest that tea oil yield could be improved by enhanced expression of CoFBA and CoSAD genes in transgenic plants.