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Abstract Camellia-oil trees are economically valuable, oil-rich species within the genus Camellia, family Theaceae. Among these species, C. oleifera, a member of Section Oleifera in the genus, is the most extensively cultivated in China. In this study, we assembled the mitochondrial genomes (mitogenomes) of two Camellia species, namely C. oleifera and C. lanceoleosa. These two species are closely related and belong to the same genus and section, with C. oleifera being hexaploid and C. lanceoleosa being diploid. The mitogenome of C. oleifera is comprised of 1,039,838 base pairs (bp), and C. lanceoleosa is comprised of 934,155 bp. Both genomes exhibit a multipartite genome structure, which is supported by our PCR experiments. We conducted codon usage and RNA editing site analysis on these two mitogenomes, which showed highly consistent results. However, analysis of repetitive sequences and mitochondrial plastid sequences (MTPTs) revealed differences between the two mitogenomes. Phylogenetic analysis indicated that these two species clustered together, suggesting a close evolutionary relationship. The collinearity analysis results showed extensive genome rearrangements in the mitogenomes of Camellia species. We successfully assembled the mitogenomes of C. oleifera and C. lanceoleosa, marking a significant advancement in understanding camellia-oil tree mitogenomes. Unlike circular mitogenomes reported before, our research confirms multiple-branched configurations in these two species. This sheds light on mitogenome structural complexities and contributes to our understanding of evolutionary processes. Additionally, these results enrich Camellia genetic resources and expand our knowledge of mitogenome variation.

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.

Background Colletotrichum fructicola is a predominant anthracnose species in Camellia oleifera, causing various adverse effects. Traditional intercropping Vernicia fordii with C. oleifera may enhance anthracnose resistance, but the mechanism remains elusive. Methods We utilized UPLC-MS/MS and acid-base detection to identify the major antimicrobial alkaloid components in the V. fordii leaf extract. Subsequently, by adding different concentrations of V. fordii leaf extract for cultivating C. fructicola, with untreated C. fructicola as a control, we investigated the impact of the V. fordii leaf extract, cell wall integrity, cell membrane permeability, MDA, and ROS content changes. Additionally, analysis of key pathogenic genes of C. fructicola confirmed that the V. fordii leaf extract inhibits the growth of the fungus through gene regulation. Results This study discovered the alkaloid composition of V. fordii leaf extract by UPLC-MS/MS and acid-base detection, such as trigonelline, stachydrine, betaine, and O-Phosphocholine. V. fordii leaf extract successfully penetrated C. fructicola mycelia, damaged cellular integrity, and increased ROS and MDA levels by 1.75 and 2.05 times respectively, thereby inhibiting C. fructicola proliferation. By analyzing the key pathogenic genes of C. fructicola, it was demonstrated that the antifungal function of V. fordii leaf extract depends mainly on the regulation of RAB7 and HAC1 gene expression. Therefore, this study elucidates the mechanism of V. fordii -C. oleifera intercropping in strengthening anthracnose resistance in C. oleifera, contributing to efficient C. oleifera cultivation.

Cytomegalovirus reactivation (CMVr) and bloodstream infections (BSI) are the most common infectious complications in patients after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Both are associated with great high morbidity whilst the BSI is the leading cause of mortality. This retrospective study evaluated the incidence of CMVr and BSI, identified associated risk factors, assessed their impact on survival in allo-HSCT recipients during the first 100 days after transplantation. The study comprised 500 allo-HSCT recipients who were CMV DNA-negative and CMV IgG-positive before allo-HSCT. Amongst them, 400 developed CMVr and 75 experienced BSI within 100 days after allo-HSCT. Multivariate regression revealed that graft failure and acute graft-versus-host disease were significant risk factors for poor prognosis, whereas CMVr or BSI alone were not. Amongst all 500 patients, 56 (14%) developed both CMVr and BSI in the 100 days after HSCT, showing significantly reduced 6-month overall survival (p = 0.003) and long-term survival (p = 0.002). Specifically, in the initial post-transplant phase (within 60 days), BSI significantly elevate mortality risk, However, patients who survive BSI during this critical period subsequently experience a lower mortality risk. Nevertheless, the presence of CMVr in patients with BSI considerably diminishes their long-term survival prospects. This study provides real-world data on the impact of CMVr and BSI following transplantation on survival, particularly in regions such as China, where the prevalence of CMV IgG-positivity is high. The findings underscore the necessity for devising and executing focused prevention and early management strategies for CMVr and BSI to enhance outcomes for allo-HSCT recipients.

Callose is an important linear form of polysaccharide synthesized in plant cell walls. It is mainly composed of β-1,3-linked glucose residues with rare amount of β-1,6-linked branches. Callose can be detected in almost all plant tissues and are widely involved in various stages of plant growth and development. Callose is accumulated on plant cell plates, microspores, sieve plates, and plasmodesmata in cell walls and is inducible upon heavy metal treatment, pathogen invasion, and mechanical wounding. Callose in plant cells is synthesized by callose synthases located on the cell membrane. The chemical composition of callose and the components of callose synthases were once controversial until the application of molecular biology and genetics in the model plant Arabidopsis thaliana that led to the cloning of genes encoding synthases responsible for callose biosynthesis. This minireview summarizes the research progress of plant callose and its synthetizing enzymes in recent years to illustrate the important and versatile role of callose in plant life activities.

The global pandemic, COVID-19, has dealt a heavy blow to the tourism industry. Therefore, exploring the mechanisms influencing travel intention in the post-epidemic era can help provide management insights for the recovery of the travel market. Relying on the logic of social cognition theory, we conducted an empirical analysis from the perspective of trust and found that institutional trust and interpersonal trust can positively predict travel intention in the context of the epidemic, while travelers’ health risk perception and safety self-efficacy mediate the relationship between trust and travel intention. Moreover, we verified the moderating role of tourists’ psychological resilience. Further, the study confirms that China’s active prevention policy not only reduces the physical health harm caused by the epidemic, but also effectively increases individuals’ institutional trust in a proactive government. Through China’s active anti-epidemic policy, individuals were able to counteract the negative impact of the COVID 19 epidemic on their travel intention. Further, theoretical and practical implications are discussed.

Brown leaf spot disease caused by Nigrospora guilinensis on Phellodendron chinense occurs in a large area in Dayi County, Chengdu City, Sichuan Province, China each year. This outbreak has severely reduced the production of Chinese medicinal plants P. chinense and caused substantial economic losses. The bacterial isolate JKB05 was isolated from the healthy leaves of P. chinense, exhibited antagonistic effects against N. guilinensis and was identified as Bacillus megaterium. The following fermentation medium and conditions improved the inhibitory effect of B. megaterium JKB05 on N. guilinensis: 2% glucose, 0.1% soybean powder, 0.1% KCl, and 0.05% MgSO4; initial concentration 6 × 106 cfu/ml, and a 42-h optimal fermentation time. A composite of 0.1% nano-SiO2 JKB05 improved the thermal stability, acid-base stability and ultraviolet resistance by 16%, 12%, and 38.9%, respectively, and nano-SiO2 was added to the fermentation process. The best formula for the wettable powder was 35% kaolin, 4% polyethylene glycol, 8% Tween, and 2% humic acid. The following quality test results for the wettable powder were obtained: wetting time 87.0 s, suspension rate 80.33%, frequency of microbial contamination 0.08%, pH 7.2, fineness 95.8%, drying loss 1.47%, and storage stability ≥83.5%. A pot experiment revealed that the ability of JKB05 to prevent fungal infections on P. chinense increased considerably and achieved levels of control as high as 94%. The use of nanomaterials significantly improved the ability of biocontrol bacteria to control this disease.

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.

Thirty-four strains of bacteria were isolated from Phellodendron amurense. Using Nectria haematococca as an indicator strain, the best strain, B18, was obtained by the growth rate method. The morphological, physiological and biochemical characteristics of strain B18 and its 16S DNA gene sequence were identified, and the biocontrol effect of strain B18 was assessed in pot and field tests, as well as in a field-control test. Drilling methods were used to determine the antibacterial activity of metabolites from strain B18 and their effects on the growth of pathogen mycelia and spores. The best bacteriostatic rate was 85.4%. B18 can hydrolyse starch and oxidize glucose but does not produce gas; a positive result was obtained in a gelatine liquefaction test. According to 16S DNA gene sequencing, strain B18 is Bacillus methylotrophicus (GenBank accession number: MG457759). The results of pot and field-control trials showed 98% disease control when inoculating 108 cfu/ml of the strain. The disease control effect of the B18 culture liquid (concentrations of 108, 2 × 106, 106, 5 × 105 and 2.5 × 105 cfu/ml) in the field-control test was higher than 80%, and the cure rate of the original delivery solution was 96%. Therefore, in the practical forestry production, a 2.5 × 105 cfu/ml culture liquidshould be applied in advance to achieve good control effects.

Background Camellia oleifera is an important oil-yielding woody plant native to China. Tea oil extracted from the seeds is rich in health-beneficial compounds. Huajin is a high-yielding elite variety of C. oleifera, with large fruits and remarkable resilience, widely cultivated in southern China; however, its seedling quality tends to be uneven. At present, techniques such as grafting, and cuttings are primarily adopted to propagate C. oleifera. These approaches are susceptible to environmental constraints owing to the long growth period, resulting in the lack of C. oleifera seedlings. Methods to make the cultivation more economical are warranted; this can be facilitated by tissue culture technology to provide good-quality seedlings in a short time. Methods In vitro cultured plantlets of C. oleifera Huajin were exposed to red light (RL), blue light (BL), red:blue light at a 4:1 ratio (R4:B1), and red:blue light at a 1:4 ratio (R1:B4); white light (WL) was used as the control treatment. To investigate the influence of light spectral quality on the proliferation coefficient, photosynthetic pigments, soluble proteins, plant height, leaf shape, Rubisco enzyme activity, and stomata and leaf anatomical features. Results The highest proliferation coefficient was observed under combined red and blue (4:1) light. In addition, this treatment resulted in the second highest chlorophyll content, the thickest palisade and spongy tissues, and consequently, the thickest leaves. The same treatment resulted in the second highest stomatal density, albeit concomitantly with the smallest average stomatal length and width. Discussion These results indicate that high-quality propagation of Huajin shoots can be achieved by culturing the plants in vitro under a combination of red and blue (4:1) lights. Previous studies have shown that red and blue lights improve rooting and transplanting rates of tissue culture seedlings. Hence, future research should focus on the effect of light quality on rooting and transplanting of tissue culture plantlets of Huajin and its specific molecular mechanisms.

Galinsoga parviflora is an invasive weed in southwest of Chinese agricultural systems and commonly used as medicine and food. In this study, the complete chloroplast genome of the G. parviflora was assembled from the whole genome Illumina sequencing data. The circular genome is 151,811 bp in size, which composed of one large single-copy (LSC) and one small single-copy (SSC) regions of 83,594 bp and 18,141 bp, respectively, and separated by a pair of inverted repeat (IR) regions of 25,038 bp each. It encodes a total of 113 gene species (80 protein-coding, 29 tRNA, and four rRNA species), in which 19 of them with double copies. The overall GC content is 37.7% while the GC content of the LSC, SSC, and IR regions are 35.8%, 31.3%, and 43.1%, separately. Phylogenetic analysis indicated that Galinsoga parviflora was closely related to Galinsoga quadriradiata.

The complete chloroplast genome of Conyza canadensis (GenBank accession number: MK737940) was obtained by using Illumina HiSeq X Ten in this study. The circular Conyza canadensis chloroplast genome is 152,721 bp long and comprises of a pair of inverted repeat (IR) regions of 25,004 bp each, a large single-copy (LSC) region of 84,280 bp, and a small single-copy (SSC) region of 18,433 bp. The complete chloroplast genome contains 114 unique genes, including 80 protein-coding genes, 30 tRNAs, and 4rRNAs. Phylogenetic analysis of the protein-coding genes revealed that Conyza canadensis was closely related to Conyza bonariensis.

Pueraria montana var. lobata is a traditional Chinese herb with various medicinal purposes. In this study, the complete chloroplast genome of the P. montana var. lobata was obtained by using Illumina HiSeq X Ten. The chloroplast genome was 153,411 bp long, which consisted of a large single-copy (LSC) region of 84, 131 bp and a short single-copy (SSC) region of 17,990 bp separated by a pair of inverted repeat (IR) regions of 25,645 bp. The whole chloroplast genome contained 111 gene species including 77 protein-coding genes (PCG), 30 tRNA, and 4 rRNA species, with 19 of them occurring in double copies. Introns were detected in 12 PCG and 6 tRNA species. The overall GC content is 35.4%. Phylogenetic analysis indicated that P. montana var. lobata was relatively close to Pachyrhizus erosus in phylogeny.

The complete chloroplast genome of Aesculus chinensis was obtained with Illumina HiSeq X Ten. The chloroplast genome is 155,528 bp in length, including a pair of inverted repeat (IR) regions of 25,656 bp, a large single-copy (LSC) region of 85,489 bp, and a small single-copy (SSC) region of 18,727 bp. It contains 115 genes, including 80 protein-coding genes, 31 transfer RNAs, and four ribosomal RNAs. The total GC content is 37.9%, whereas the corresponding values of the LSC, SSC, and IR regions are 36.1%, 31.8%, and 43.2%, separately. Phylogenetic analysis of the protein-coding genes showed a close relationship with Aesculus wangii in Hippocastanaceae.

Cassia fistula L. which is known as “Golden Shower”, is used as an ornamental plant due to its flowers, and fruit parts of this plant have a high medicinal value. There are few reports providing a comprehensive overview of the chemical composition of its fruit or explaining the differences between samples from different sources because of the complexity of its chemical components. The purpose of the present study was to establish a fingerprint evaluation system based on Similarity Analysis (SA), Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) for the composition identification and quality control of this herb. Twelve samples from Xinjiang and Sichuan provinces in China and India were analyzed by HPLC, and there were fifteen common peaks in the twelve batches. Molecular weight and formula information can be derived from thirty-one peaks by UHPLC/LTQ-Orbitrap MSn, molecular structure information of twenty components was obtained, of which ten compounds were identified by comparison with standard materials. Samples of twelve batches were divided according to their similarity into four groups, which were basically consistent with three different C.fistula fruit-producing areas. Five compounds were finally considered to be chemical markers to determine the quality of this herb. A fingerprints method combined with chemometrics was established to differentiate the origin of the fruit of C. fistula which has the advantages of effectivity and convenience, laying the foundation for the quality evaluation of this herb from different sources.

Bolbostemma paniculatum is a traditional Chinese medicine (TCM) showed various therapeutic effects. Owing to its complex chemical composition, few investigations have acquired a comprehensive cognition for the chemical profiles of this herb and explicated the differences between samples collected from different places. In this study, a strategy based on UPLC tandem LTQ-Orbitrap MSn was established for characterizing chemical components of B. paniculatum. Through a systematic identification strategy, a total of 60 components in B. paniculatum were rapidly separated in 30 min and identified. Then based on peak intensities of all the characterized components, principle component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to classify 18 batches of B. paniculatum into four groups, which were highly consistent with the four climate types of their original places. And five compounds were finally screened out as chemical markers to discriminate the internal quality of B. paniculatum. As the first study to systematically characterize the chemical components of B. paniculatum by UPLC-MSn, the above results could offer essential data for its pharmacological research. And the current strategy could provide useful reference for future investigations on discovery of important chemical constituents in TCM, as well as establishment of quality control and evaluation method.

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.

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.

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 withmaloideous 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. [ABSTRACT FROM AUTHOR]

As a result of its high photosynthetic efficiency, the tung tree (Vernicia fordii) is a fast-growing heliophile, yielding fruit within 3 years. In addition, tung oil extracted from the fruit seeds is an environmentally friendly paint used widely in China. However, mutual shading inside a tung tree canopy leads to a low yield of fruit because of weak or dead lower branches. In this project, a pot experiment was conducted to understand the growth, physiological, anatomical structure, and biochemical responses of tung trees under various shading levels. Tung tree seedlings were subjected to different light intensities--100% sunlight (no cover), L100; 75% sunlight (25% shading), L75; 50% sunlight (50% shading), L50; and 20% sunlight (80% shading), L20--from June to August. Results indicate that the L75 treatment reduced significantly the net photosynthetic rate (Pn), stomatal conductance (gS), transpiration rate (E), total aboveground and root dry weight (DW), maximum net photosynthetic rate (Amax), and maximum rate of electron transport at saturating irradiance (Jmax) compared with the control, although plant height and leaf area (LA) were not reduced. Lower light intensities (L50 and L20) and longer duration of treatment led to greater reduction in growth, leaf thickness, and photosynthetic potential (Amax and Jmax). Chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll content were increased in the L50 and L20 treatments compared with L100 and L75. There was no significant reduction in the enzyme activities of ribulose-1,5-bisphosphate carboxylase (Rubisco) and phosphoenolpyruvate (PEPC) of the seedlings using the L75 treatment; however, lower light intensities (L50 and L20) and longer duration of shade treatment resulted in a significant reduction in enzyme activity. In summary, the results suggest that tung trees have greater photosynthetic activity under high light intensity. Shading, even at 20%, especially for the longer term, reduced photosynthetic efficiency and growth. To prevent growth reduction, tung trees should be grown under full sun with a daily light integral (DLI) of ≈46 mol·m-2·d-1, and mutual shading should be avoided by proper spacing and pruning. [ABSTRACT FROM AUTHOR]