Search

This study aimed to optimize the culture conditions of the termite-derived fungus Aspergillus chevalieri BYST01 for the production of physcion, a characteristic component of the traditional herb rhubarb, which has been commercially approved as a botanical fungicide in China. First, potato dextrose broth was screened as the suitable basal medium for further optimization, with an initial yield of 28.0 mg/L. Then, the suitable carbon source, fermentation time, temperature, pH value, and the rotary shaker speed for physcion production were determined using the one-variable-at-a-time method. Based on the results of single factors experiments, the variables with statistically significant effects on physcion production were further confirmed using the Plackett-Burman design (PBD). Among the five variables, temperature, initial pH, and rotary shaker speed were identified as significant factors (P < 0.05) for physcion productivity in the PDB and were further analyzed by response surface methodology (RSM). Finally, we found that the maximum physcion production (82.0 mg/L) was achieved under the following optimized conditions:initial pH 6.6, rotary shaker speed of 177 rpm, temperature of 28 °C, and glucose concentration of 30 g/L in PDB medium after 11 d of fermentation. The yield of physcion under the optimized culture conditions was approximately threefold higher than that obtained using the basal culture medium. Furthermore, the optimum fermentation conditions in the 5-L bioreactor achieved a maximal physcion yield of 85.2 mg/L within 8 d of fermentation. Hence, response surface methodology proved to be a powerful tool for optimizing physcion production by A. chevalieri BYST01. This study may be helpful in promoting the application of physcion produced by A. chevalieri BYST01 to manage plant diseases. [ABSTRACT FROM AUTHOR]

SUMMARY: Hydrolyzable tannins (HTs), a class of polyphenolic compounds found in dicotyledonous plants, are widely used in food and pharmaceutical industries because of their beneficial effects on human health. Although the biosynthesis of simple HTs has been verified at the enzymatic level, relevant genes have not yet been identified. Here, based on the parent ion‐fragment ion pairs in the feature fragment data obtained using UPLC‐Q‐TOF‐/MS/MS, galloyl phenolic compounds in the leaves of Camellia sinensis and C. oleifera were analyzed qualitatively and quantitatively. Correlation analysis between the transcript abundance of serine carboxypeptidase‐like acyltransferases (SCPL‐ATs) and the peak area of galloyl products in Camellia species showed that SCPL3 expression was highly correlated with HT biosynthesis. Enzymatic verification of the recombinant protein showed that CoSCPL3 from C. oleifera catalyzed the four consecutive steps involved in the conversion of digalloylglucose to pentagalloylglucose. We also identified the residues affecting the enzymatic activity of CoSCPL3 and determined that SCPL‐AT catalyzes the synthesis of galloyl glycosides. The findings of this study provide a target gene for germplasm innovation of important cash crops that are rich in HTs, such as C. oleifera, strawberry, and walnut. [ABSTRACT FROM AUTHOR]

Gonadotropin-releasing hormone (GnRHa) is the first choice for the treatment of patients with central precocious puberty (CPP). However, the effects of GnRHa on the endocrine system of CPP patients, including insulin sensitivity, lipid level, thyroid function, bone mineral density (BMD), and testosterone (T) level, are currently contradictory. Therefore, the long-term safety of GnRHa therapy remains controversial. A systematic literature search was performed using PubMed, Embase, Cochrane Library, and CNKI databases. The changes in HOMA-IR, TG, LDL-C, HDL-C, TSH, FT3, FT4, T, and BMD in CPP patients before and after GnRHa treatment were compared by meta-analysis. As the heterogeneity between studies, we estimated standard deviation mean differences (SMDs) and 95 % confidence intervals (CIs) using a random-effects model. Egger's test was used to assess publication bias. A total of 22 studies were included in our meta-analysis. Compared with before GnRHa treatment, there were no statistically significant differences in endocrine indicators including HOMA-IR, TG, LDL-C, HDL-C, TSH, FT4, FT3, T, and BMD of CPP patients treated with GnRHa. Treatment with GnRHa for central precocious puberty will not increase the adverse effect on the endocrine system. [ABSTRACT FROM AUTHOR]

Tea is an important cash crop that is often consumed by chewing pests, resulting in reduced yields and economic losses. It is important to establish a method to quickly identify the degree of damage to tea plants caused by leaf‐eating insects and screen green control compounds. This study was performed through the combination of deep learning and targeted metabolomics, in vitro feeding experiment, enzymic analysis and transient genetic transformation. A small target damage detection model based on YOLOv5 with Transformer Prediction Head (TPH‐YOLOv5) algorithm for the tea canopy level was established. Orthogonal partial least squares (OPLS) was used to analyze the correlation between the degree of damage and the phenolic metabolites. A potential defensive compound, (‐)‐epicatechin‐3‐O‐caffeoate (EC‐CA), was screened. In vitro feeding experiments showed that compared with EC and epicatechin gallate, Ectropis grisescens exhibited more significant antifeeding against EC‐CA. In vitro enzymatic experiments showed that the hydroxycinnamoyl transferase (CsHCTs) recombinant protein has substrate promiscuity and can catalyze the synthesis of EC‐CA. Transient overexpression of CsHCTs in tea leaves effectively reduced the degree of damage to tea leaves. This study provides important reference values and application prospects for the effective monitoring of pests in tea gardens and screening of green chemical control substances. Summary statement: Based on deep learning and targeted metabolomics, a model was established and (‐)‐epicatechin‐3‐O‐caffeoate (EC‐CA) was screened to have the function of defense against chewing pests, and hydroxycinnamoyl transferase (HCT) was identified as a substrate promiscuity that could efficiently catalyze the synthesis of EC‐CA. [ABSTRACT FROM AUTHOR]

Background: In nasopharyngeal cancer (NPC), women have a lower incidence and mortality rate than men. Whether sex influences the prognosis of NPC patients remains debatable. We retrospectively examined the influence of sex on treatment-related side effects and prognosis in NPC. Methods: Clinical data of 1,462 patients with NPC treated at the Southern Hospital of Southern Medical University from January 2004 to December 2015 were retrospectively examined. Statistical analysis was performed to assess differences in overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival(LRFS), and progression-free survival(PFS), as well as treatment-related adverse effects, including myelosuppression, gastrointestinal responses, and radiation pharyngitis and dermatitis, between men and women. Results: Women had better 5-year OS (81.5% vs. 87.1%, P = 0.032) and DMFS (76.2% vs. 83.9%, P = 0.004) than men. Analysis by age showed that the prognoses of premenopausal and menopausal women were better than those of men, whereas prognoses of postmenopausal women and men were not significantly different. Additionally, women had a better prognosis when stratified by treatment regimen. Furthermore, chemotherapy-related adverse effects were more severe in women than in men; however, the incidences of radiation laryngitis and dermatitis were not significantly different between the sexes. Logistic regression analysis revealed that the female sex was an independent risk factor for severe myelosuppression and gastrointestinal reactions. Conclusions: Chemotherapy-related side effects are more severe but the overall prognosis is better in women with NPC than in men with NPC. Patients may benefit from a personalized treatment approach for NPC. Trial registration: This study was approved by the Medical Ethics Committee of Nanfang Hospital of the Southern Medical University (NFEC-201,710-K3). [ABSTRACT FROM AUTHOR]

With the development of urbanization, a large number of village settlements have disappeared. As important carriers of ethnic and cultural heritage, village settlements are important for the continuation of folk culture and farming spirit. Building a regional ecological security pattern helps to protect the integrity of village settlements and promote the sustainable development of the Chinese nation. In this work, the importance of ecosystem services was first obtained by using the Integrated Valuation of Ecosystem Services and Tradeoffs model (In-VEST) and the revised universal soil loss equation model (RUSLE) to evaluate the regional ecosystem services in the southeastern region of Chongqing (SRC). Then, the ecological importance evaluation results were combined with the sensory evaluation results to derive ecological conservation importance areas and identify ecological source points in their high-value areas. Finally, the ecological corridors were obtained by the minimum cumulative resistance model (MCR). The regional ecological security pattern was constructed, i.e., the triangular protection area strategy of "one screen, one belt, and three cores". The results show the following: the total area of ecological source sites larger than 20 km2 in SRC is 436.02 km2, accounting for 2.28% of the area of SRC. The largest ecological patch is 69.93 km2, accounting for 16.04% of the total area of ecological source sites. Thirteen ecological source sites were identified as follows: four in Youyang County, three in Shizhu County, three in Wulong County, and one in Pengshui County. There are 78 ecological corridors with a total length of 4832.82 km, including 32 important ecological corridors with a length of about 1544.53 km and 46 potential ecological corridors with a length of about 3288.29 km. Based on the minimum cumulative model constructed by eight resistance factors, the spatial variation of the ecological resistance surface was analyzed, showing a trend of being high in the west and central part and low in the surrounding area. There are one high-value area of the resistance surface of Wulong County Nature Reserve and one high-value area of ecological sensitivity that overlap to the extreme, and which should be given sufficient protection attention. The core protected areas consist of three mountains including the Qiyao Mountain Range, the Wuling Mountain Range, and the Wulong County Nature Reserve. The ecological security pattern in SRC based on the mode of "source–ecological corridor–ecological node" can identify important ecological function areas, providing scientific guidance for sustainable development and ecological security protection in the ethnic village settlements in China. [ABSTRACT FROM AUTHOR]

SUMMARY: Plant tannases (TAs) or tannin acyl hydrolases, a class of recently reported carboxylesterases in tannin‐rich plants, are involved in the degalloylation of two important groups of secondary metabolites: flavan‐3‐ol gallates and hydrolyzable tannins. In this paper, we have made new progress in studying the function of tea (Camellia sinensis) (Cs) TA—it is a hydrolase with promiscuous acyltransferase activity in vitro and in vivo and promotes the synthesis of simple galloyl glucoses and flavan‐3‐ol gallates in plants. We studied the functions of CsTA through enzyme analysis, protein mass spectrometry, and metabolic analysis of genetically modified plants. Firstly, CsTA was found to be not only a hydrolase but also an acyltransferase. In the two‐step catalytic reaction where CsTA hydrolyzes the galloylated compounds epigallocatechin‐3‐gallate or 1,2,3,4,6‐penta‐O‐galloyl‐β‐d‐glucose into their degalloylated forms, a long‐lived covalently bound Ser159‐linked galloyl–enzyme intermediate is also formed. Under nucleophilic attack, the galloyl group on the intermediate is transferred to the nucleophilic acyl acceptor (such as water, methanol, flavan‐3‐ols, and simple galloyl glucoses). Then, metabolic analysis suggested that transient overexpression of TAs in young strawberry (Fragaria × ananassa) fruits, young leaves of tea plants, and young leaves of Chinese bayberry (Myrica rubra) actually increased the total contents of simple galloyl glucoses and flavan‐3‐ol gallates. Overall, these findings provide new insights into the promiscuous acyltransferase activity of plant TA. [ABSTRACT FROM AUTHOR]

Volatile ester compounds are important contributors to the flavor of strawberry, which affect consumer preference. Here, the GC-MS results showed that volatile esters are the basic aroma components of strawberry, banana, apple, pear, and peach, and the volatile esters were significantly accumulated with the maturation of strawberry fruits. The main purpose of this study is to discuss the relationship between carboxylesterases (CXEs) and the accumulation of volatile ester components in strawberries. FaCXE2 and FaCXE3 were found to have the activity of hydrolyzing hexyl acetate, Z-3-hexenyl acetate, and E-2-hexenyl acetate to the corresponding alcohols. The enzyme kinetics results showed that FaCXE3 had the higher affinity for hexyl acetate, E-2-hexenyl acetate, and Z-3-hexenyl acetate compared with FaCXE2. The volatile esters were mainly accumulated at the maturity stages in strawberry fruits, less at the early stages, and the least during the following maturation stages. The expression of FaCXE2 gradually increased with fruit ripening and the expression level of FaCXE3 showed a decreasing trend, which suggested the complexity of the true function of CXEs. The transient expression of FaCXE2 and FaCXE3 genes in strawberry fruits resulted in a significantly decreased content of volatile esters, such as Z-3-hexenyl acetate, methyl hexanoate, methyl butyrate, and other volatile esters. Taken together, FaCXE2 and FaCXE3 are indeed involved in the regulation of the synthesis and degradation of strawberry volatile esters. [ABSTRACT FROM AUTHOR]

Key message: Two 4-coumarate: CoA ligase genes in tea plant involved in phenylpropanoids biosynthesis and response to environmental stresses. Tea plant is rich in flavonoids benefiting human health. Lignin is essential for tea plant growth. Both flavonoids and lignin defend plants from stresses. The biosynthesis of lignin and flavonoids shares a key intermediate, 4-coumaroyl-CoA, which is formed from 4-coumaric acid catalyzed by 4-coumaric acid: CoA ligase (4CL). Herein, we report two 4CL paralogs from tea plant, Cs4CL1 and Cs4CL2, which are a member of class I and II of this gene family, respectively. Cs4CL1 was mainly expressed in roots and stems, while Cs4CL2 was mainly expressed in leaves. The promoter of Cs4CL1 had AC, nine types of light sensitive (LSE), four types of stress-inducible (SIE), and two types of meristem-specific elements (MSE). The promoter of Cs4CL2 also had AC and nine types of LSEs, but only had two types of SIEs and did not have MSEs. In addition, the LSEs varied in the two promoters. Based on the different features of regulatory elements, three stress treatments were tested to understand their expression responses to different conditions. The resulting data indicated that the expression of Cs4CL1 was sensitive to mechanical wounding, while the expression of Cs4CL2 was UV-B-inducible. Enzymatic assays showed that both recombinant Cs4CL1 and Cs4CL2 transformed 4-coumaric acid (CM), ferulic acid (FR), and caffeic acid (CF) to their corresponding CoA ethers. Kinetic analysis indicated that the recombinant Cs4CL1 preferred to catalyze CF, while the recombinant Cs4CL2 favored to catalyze CM. The overexpression of both Cs4CL1 and Cs4CL2 increased the levels of chlorogenic acid and total lignin in transgenic tobacco seedlings. In addition, the overexpression of Cs4CL2 consistently increased the levels of three flavonoid compounds. These findings indicate the differences of Cs4CL1 and Cs4CL2 in the phenylpropanoid metabolism. [ABSTRACT FROM AUTHOR]

SUMMARY: Serine carboxypeptidase‐like acyltransferases (SCPL‐ATs) play a vital role in the diversification of plant metabolites. Galloylated flavan‐3‐ols highly accumulate in tea (Camellia sinensis), grape (Vitis vinifera), and persimmon (Diospyros kaki). To date, the biosynthetic mechanism of these compounds remains unknown. Herein, we report that two SCPL‐AT paralogs are involved in galloylation of flavan‐3‐ols: CsSCPL4, which contains the conserved catalytic triad S‐D‐H, and CsSCPL5, which has the alternative triad T‐D‐Y. Integrated data from transgenic plants, recombinant enzymes, and gene mutations showed that CsSCPL4 is a catalytic acyltransferase, while CsSCPL5 is a non‐catalytic companion paralog (NCCP). Co‐expression of CsSCPL4 and CsSCPL5 is likely responsible for the galloylation. Furthermore, pull‐down and co‐immunoprecipitation assays showed that CsSCPL4 and CsSCPL5 interact, increasing protein stability and promoting post‐translational processing. Moreover, phylogenetic analyses revealed that their homologs co‐exist in galloylated flavan‐3‐ol‐ or hydrolyzable tannin‐rich plant species. Enzymatic assays further revealed the necessity of co‐expression of those homologs for acyltransferase activity. Evolution analysis revealed that the mutations of the CsSCPL5 catalytic residues may have taken place about 10 million years ago. These findings show that the co‐expression of SCPL‐ATs and their NCCPs contributes to the acylation of flavan‐3‐ols in the plant kingdom. [ABSTRACT FROM AUTHOR]

Unlike that of other crops, the growth of tea plants can be promoted by aluminum, but its regulation mechanism remains unclear. Some endophytes can also promote growth of plant hosts. In this paper, tea roots treated with aluminum were used to study the growth-promoting traits and aluminum tolerance of endophytes. Meta-16S rDNA analysis revealed that Burkholderia was enriched in tea roots after aluminum treatment, and it was the dominant strain for hydroponic tea roots and field tea roots. Actinomycetes constituted the dominant strains in hydroponic tea seedlings treated with aluminum. Sixteen endophytic bacteria, including 12 strains of Firmicutes , 2 strains of Proteobacteria and 2 strains of Actinomycetes , were isolated and identified from hydroponic tea roots treated with different aluminum concentrations. Growth-promoting activity analysis showed that the isolated endophytic bacteria all had more than one plant growth-promoting trait. Among them, B4 (Bacillus nealsonii), B8 (Brevibacterium frigoritolerans) and A2 (Nocardia nova) bacteria each had three growth-promoting traits. Aluminum tolerance ability analysis indicated that endophyte A1 (Leifsonia shinshuensis) had the strongest aluminum tolerance ability, up to 200 mg l−1 aluminum. Plant–bacteria interactions showed that endophytes A1, A2 and B4 and their synthetic community all had a growth-promoting effect on the growth of wheat lateral roots. Moreover, endophytes A1 and B4 alleviated aluminum stress in wheat. Endophyte A1 also promoted the growth of tea cuttings, especially lateral roots, with/without aluminum. Taken together, aluminum enhanced the distribution of aluminum-tolerant and growth-promoting bacteria, thereby promoting the growth of tea roots. This study provides a new aspect for research on the mechanism by which aluminum promotes tea plant growth. [ABSTRACT FROM AUTHOR]

Flavonoids, including flavonol derivatives, are the main astringent compounds of tea and are beneficial to human health. Many researches have been conducted to comprehensively identify and characterize the phenolic compounds in the tea plant. However, the biological function of tea flavonoids is not yet understood, especially those accumulated in floral organs. In this study, the metabolic characteristics of phenolic compounds in different developmental stages of flower buds and various parts of the tea flower were investigated by using metabolomic and transcriptomic analyses. Targeted metabolomic analysis revealed varying accumulation patterns of different phenolic polyphenol compounds during flowering; moreover, the content of flavonol compounds gradually increased as the flowers opened. Petals and stamens were the main sites of flavone and flavonol accumulation. Compared with those of fertile flowers, the content of certain flavonols, such as kaempferol derivatives, in anthers of hybrid sterile flowers was significantly low. Transcriptomic analysis revealed different expression patterns of genes in the same gene family in tea flowers. The CsFLSb gene was significantly increased during flowering and was highly expressed in anthers. Compared with fertile flowers, CsFLSb was significantly downregulated in sterile flowers. Further functional verification of the three CsFLS genes indicated that CsFLSb caused an increase in flavonol content in transgenic tobacco flowers and that CsFLSa acted in leaves. Taken together, this study highlighted the metabolic properties of phenolic compounds in tea flowers and determined how the three CsFLS genes have different functions in the vegetative and reproductive organs of tea plants. Furthermore, CsFLSb could regulated flavonol biosynthesis in tea flowers, thus influencing fertility. This research is of great significance for balancing the reproductive growth and vegetative growth of tea plants. [ABSTRACT FROM AUTHOR]

Aggressiveness of cancers, like prostate cancer, has been found to be associated with elevated expression of the microsomal prostaglandin E synthase-1 (mPGES-1). Here, we investigated whether KH176m (the active metabolite of sonlicromanol), a recently discovered selective mPGES-1 inhibitor, could affect prostate cancer cells-derived spheroid growth. We demonstrated that KH176m suppressed mPGES-1 expression and growth of DU145 (high mPGES-1 expression)-derived spheroids, while it had no effect on the LNCaP cell line, which has low mPGES-1 expression. By addition of exogenous PGE2, we found that the effect of KH176m on mPGES-1 expression and spheroid growth is due to the inhibition of a PGE2-driven positive feedback control-loop of mPGES-1 transcriptional regulation. Cancer stem cells (CSCs) are a subset of cancer cells exhibiting the ability of self-renewal, plasticity, and initiating and maintaining tumor growth. Our data shows that mPGES-1 is specifically expressed in this CSCs subpopulation (CD44+CD24-). KH176m inhibited the expression of mPGES-1 and reduced the growth of spheroids derived from the CSC. Based on the results obtained we propose selective mPGES-1 targeting by the sonlicromanol metabolite KH176m as a potential novel treatment approach for cancer patients with high mPGES-1 expression. [ABSTRACT FROM AUTHOR]

The recent and ongoing outbreak of coronavirus disease (COVID‐19) is a huge global challenge. The outbreak, which first occurred in Wuhan City, Hubei Province, China and then rapidly spread to other provinces and to more than 200 countries abroad, has been declared a global pandemic by the World Health Organization. Those with compromised immune systems and/or existing respiratory, metabolic or cardiac problems are more susceptible to the infection and are at higher risk of serious illness or even death. The present review was designed to report important functional food plants with immunomodulatory and anti‐viral properties. Data on medicinal food plants were retrieved and downloaded from English‐language journals using online search engines. The functional food plants herein documented might not only enhance the immune system and cure respiratory tract infections but can also greatly impact the overall health of the general public. As many people in the world are now confined to their homes, inclusion of these easily accessible plants in the daily diet may help to strengthen the immune system and guard against infection by SARS‐CoV‐2. This might reduce the risk of COVID‐19 and initiate a rapid recovery in cases of SARS‐CoV‐2 infection. [ABSTRACT FROM AUTHOR]

Summary: Plant tannins, including condensed tannins (CTs) and hydrolyzable tannins (HTs), are widely distributed in the plant kingdom. To date, tannase (TA) – is a type of tannin acyl‐hydrolase hydrolyzing HTs, CT monomer gallates and depsides – has been reported in microbes only. Whether plants express TA remains unknown.Herein, we report plant TA genes. A native Camellia sinensis TA (CsTA) is identified from leaves. Six TAs are cloned from tea, strawberry (Fragaria × ananassa, Fa) and four other crops. Biochemical analysis shows that the native CsTA and six recombinant TAs hydrolyze tannin compounds, depsides and phenolic glycosides.Transcriptional and metabolic analyses reveal that the expression of CsTA is oppositely associated with the accumulation of galloylated catechins. Moreover, the transient overexpression and RNA interference of FaTA are positively associated with the accumulation of ellagitannins in strawberry fruit. Phylogenetic analysis across different kingdoms shows that 29 plant TA homologs are clustered as a plant‐specific TA clade in class I carboxylesterases. Further analysis across the angiosperms reveals that these TA genes are dispersed in tannin‐rich plants, which share a single phylogenetic origin c. 120 million yr ago.Plant TA is discovered for the first time in the plant kingdom and is shown to be valuable to improve tannin compositions in plants. [ABSTRACT FROM AUTHOR]

Summary: The plant flavonoid dogma proposes that labile plant flavonoid carbocations (PFCs) play vital roles in the biosynthesis of proanthocyanidins (PAs). However, whether PFCs exist in plants and how PFCs function remain unclear. Here, we report the use of an integrative strategy including enzymatic assays, mutant analysis, metabolic engineering, isotope labeling and metabolic profiling to capture PFCs and demonstrate their functions. In anthocyanidin reductase (ANR) assays, an (−)‐epicatechin conjugate was captured in protic polar nucleophilic methanol alone or methanol−HCl extracts. Tandem mass spectrum (MS/MS) analysis characterized this compound as an (−)‐epicatechin‐4‐O‐methyl (EOM) ether, which resulted from (−)‐epicatechin carbocation and the methyl group of methanol. Acid‐based catalysis of procyanidin B2 and B3 produced four compounds, which were annotated as two EOM and two (+)‐catechin‐4‐O‐methyl (COM) ethers. Metabolic profiling of seven PA pathway mutants showed an absence or reduction of two EOM ether isomers in seeds. Camellia sinensis ANRa (CsANRa), leucoanthocyanidin reductase c (CsLARc), and CsMYB5b (a transcription factor) were independently overexpressed for successful PA engineering in tobacco. The EOM ether was remarkably increased in CsANRa and CsMYB5b transgenic flowers. Further metabolic profiling for eight green tea tissues revealed two EOM and two COM ethers associated with PA biosynthesis. Moreover, an incubation of (−)‐epicatechin or (+)‐catechin with epicatechin carbocation in CsANRa transgenic flower extracts formed dimeric procyanidin B1 or B2, demonstrating the role of flavan‐3‐ol carbocation in the formation of PAs. Taken together, these findings indicated that flavan‐3‐ol carbocations exist in extracts and are involved in the biosynthesis of PAs of plants. Significance Statement: Although the dogma of plant flavonoids proposes that labile plant flavonoids carbocations (PFCs) exist to associate with the biosynthesis of proanthocyanidins (PAs), supportive evidence is lacking. Data from biochemical analysis, isotope labeling, genetic analysis, metabolic engineering and metabolic profiling demonstrate that PFCs are involved in the biosynthesis of PAs. [ABSTRACT FROM AUTHOR]

Main conclusion: Biochemical, transgenic, and genetic complementation data demonstrate that three glutathione S-transferases are involved in the storage of anthocyanins, flavonols, and proanthocyanins in plant cells. Flavonoids are compounds in tea (Camellia sinensis) that confer the characteristic astringent taste of tea beverages; these compounds have numerous benefits for human health. In plant cells, flavonoids are synthesized in different locations within the cytoplasm and are then transported and finally stored in vacuoles. To date, the mechanism involved in the intracellular transport of flavonoids in tea has not been well elucidated. In this study, we report the functional characterization of three cDNAs encoding glutathione S-transferases (CsGSTs) of C. sinensis, namely, CsGSTa, CsGSTb, and CsGSTc. The expression profiles of CsGSTa and CsGSTb were positively correlated with the accumulation of flavonols, anthocyanins and proanthocyanins in tea tissues and cultivars. These three recombinant CsGSTs showed a high affinity for flavonols (kaempferol-3-O-glucoside and quercetin-3-O-glucoside) and anthocyanin (cyanidin-3-O-glucoside) in vitro but had no or weak affinity for epicatechin. In vivo, CsGSTa, CsGSTb and CsGSTc fully or partially restored the storage of anthocyanins and proanthocyanidins in transgenic tt19 mutants. Metabolic profiling revealed that the contents of anthocyanins, flavonols, and proanthocyanidins were increased in the transgenic petals of Nicotiana tabacum. Taken together, all data showed that CsGSTa, CsGSTb, and CsGSTc are associated with the storage of anthocyanins, flavonols, and proanthocyanins in C. sinensis cells. [ABSTRACT FROM AUTHOR]

Tea (Camellia sinensis) is an important cash crop that is beneficial to human health because of its remarkable content of catechins. The biosynthesis of catechins follows the flavonoid pathway, which is highly branched. Among the enzymes involved in catechin biosynthesis, ANTHOCYANIDIN SYNTHASE (CsANS) functions at a branch point and play a critical role. Our previous work has showed that the gene encoding CsANS is regulated by light signals; however, the molecular mechanism behind remains unclear. Here, we cloned a full‐length CsANS promoter and found that it contained a cis‐element recognized by Arabidopsis thaliana HOMEOBOX2 (AtHB2). AtHB2 constitutes one of the class II HOMEODOMAIN‐LEUCINE ZIPPER (HD‐ZIP) proteins, which accumulate in the dark and mediate the shade avoidance response in most angiosperms. To analyze the transcription of CsANS in vivo, β‐glucuronidase and luciferase reporter genes driven by the obtained promoter were introduced into A. thaliana and Nicotiana attenuata, respectively. In both expression systems there were indications that the A. thaliana PRODUCTION OF ANTHOCYANIN PIGMENT1 (AtPAP1), a MYB transcription factor of flavonoid biosynthesis, increased the activity of the CsANS promoter, while AtHB2 could significantly undermine the effect of AtPAP1. Yeast two‐hybrid and bimolecular fluorescence complementation assays showed that AtHB2 interacted with the A. thaliana TRANSPARENT TESTA GLABRA 1 (AtTTG1). A yeast three‐hybrid assay further suggested that AtHB2 represses the expression of CsANS and regulates its response to light signals through competitive interactions with AtTTG1. These results show that HD‐ZIP II proteins participate in light regulation of flavonoid biosynthesis. [ABSTRACT FROM AUTHOR]

Icing on transmission lines might lead to ice flashovers of insulators, collapse of towers, tripping faults of transmission lines, and other accidents. Shed spacing and shed overhang of insulators are clues for evaluating the probability of ice flashover. This paper researches imageprocessing methods for the natural icing of in-service glass insulators. Calculation methods of graphical shed spacing and graphical shed overhang are proposed via recognizing the convexity defects of the contours of an icing insulator string based on the GrabCut segmentation algorithm. The experiments are carried out with image data from our climatic chamber and the China Southern Power Grid Disaster (Icing) Warning System of Transmission Lines. The results show that the graphical shed overhang of insulators show evident change due to icing. This method can recognize the most serious icing conditions where the insulator sheds are completely bridged. Also, it can detect bridging positions including the left side, right side, or both sides of the insulator strings in the images. [ABSTRACT FROM AUTHOR]

Main conclusion: LARs promoted the biosynthesis of catechin monomers and inhibited their polymerization. The accumulation of catechin monomers and polymers was increased by up-regulating the expression of NtLAR and NtANR s in CsMYB5b transgenic tobacco. Tea is rich in polyphenolic compounds, and catechins are the major polyphenols in tea. The biosynthesis of polyphenols is closely related to the expression of the leucoanthocyanidin reductase ( LAR) and anthocyanidin reductase ( ANR) genes. In this paper, an evolutionary analysis and functional characterization of three CsLARs were performed. The phylogenetic tree showed that plant LARs could be grouped into three, including gymnosperms, monocotyledons and dicotyledons (clusters I and II). The eighth amino acid residue in a conserved LAR-specific motif is changeable due to a transversion (G → T) and transition (G → C) that occur in the corresponding codon. Therefore, plant LARs can be classified as G-type, A-type and S-type LARs due to this variable amino acid residue. Although (2R, 3S)- trans-flavan-3-ols were the products of recombinant CsLARs proteins expressed in Escherichia coli, both (2R, 3S)- trans and (2R, 3R)- cis-flavan-3-ols were detected in tobacco overexpressing CsLARs. However, a butanol/HCl hydrolysis assay indicated that overexpression of the CsLARs caused a decrease in polymerized catechins. A hybridization experiment with CsLARc + AtPAP1 also showed that no polymers other than epicatechin, catechin and glycoside were detected, although the accumulation of anthocyanins was markedly decreased. CsMYB5b promoted the biosynthesis of both flavan-3-ols and proanthocyanidins (PAs). Therefore, LARs promoted the biosynthesis of catechin monomers and inhibited their polymerization. The accumulation of catechin monomers and polymers was increased by up-regulating the expression of the NtLAR and NtANRs in CsMYB5b transgenic tobacco. [ABSTRACT FROM AUTHOR]

For in-service transmission lines, insulator icing condition depends on analysis of images collected by cameras installed on towers, and ice type analysis is mostly completed by human beings, which is infeasible to monitor a large area. Although image processing is successfully applied to segmentation of insulators from aerial images, there are few literatures on automatically determining ice types on insulators via image processing. In this paper, a recognition method of ice types on in-service glass insulators is established based on a texture feature description operator. Uniform Local Binary Patterns (ULBP) and Improved Uniform Local Binary Patterns (IULBP) were adopted for texture feature extraction of typical images of six ice types including glaze ice, heavy rime, medium rime, light rime, partial rime and snow. The six ice types are concluded based on icing insulator images and corresponding meteorological data from China Southern Power Grid Transmission Line (Icing) Online Monitoring System. Ice types are recognized by correlation coefficient calculation of texture histograms. The experiment results show that IULBP obtains better results for recognition of the six ice types as each ice type has distinguished texture features. [ABSTRACT FROM AUTHOR]

The flashover performance of insulators is significantly affected by the degrees and ways of wetting the pollution layer. However, there have only been a few reports on the wetting condition and its effects on the flashover characteristics of pollution on insulators to date. In this paper, a phase-angle difference-based method is proposed to test the wetting conditions of the pollution layer on insulators. A corresponding measuring device is also developed. The wetting process of the pollution layer on aerodynamic-type glass insulators is studied in an artificial climate chamber using the developed device. The related flashover performance is studied via the even-rising voltage method. Test results show that the phase-angle difference (PAD) curve accurately reflects the entire wetting process of the pollution layer from the initial stage, through the saturated stage to the oversaturated and washing away stages. Over the wetting process, the PAD curve initially drops sharply, and then remains stable for a few minutes before eventually rising slowly to the initial value. The PAD curve has its lowest value when the pollution layer is wetted to saturation, which occurs after approximately 5 min in our experiments. The flashover voltage characteristics of insulators are also significantly affected by the wetting conditions of the pollution layer. The flashover voltage in the saturated stage is shown to be lower than that in the other stages. Therefore, to improve the accuracy of the artificial pollution tests, quantitative methods (including PAD) should be used to obtain the exact time of wetting to saturation. [ABSTRACT FROM PUBLISHER]

[Objective] The paper was to explore the antimicrobial activities of extracts from Xylaria striata via submerged culture. [Methods] The antibacterial activities of X. striata extracts against 10 kinds of bacteria were determined using Oxford cup method and microplate assay, and the antifungal activities against nine kinds of pathogenic fungi were determined using mycelial growth rate method. [Results] The inhibition zone diameters of the mycelium extract against tested bacteria ranged from 13.0 to 17.5 mm, and that of the fermentation broth extract ranged from 10.5 to 12.7 mm. Enterobacter cloacae was the most sensitive to both mycelium extract and fermentation broth extract, with the inhibition zone diameters of 17. 1 and 12. 7 mm and the minimum inhibitory concentrations of 2. 5 and 5 mg/mL, respectively. The inhibitory effects of the mycelium extract and the fermentation broth extract against Fusarium graminearum were the greatest, and the inhibition rates were 89. 88% and 69.53%, respectively. [Conclusion] X. striata has potential antimicrobial activity and deserves to be further studied. [ABSTRACT FROM AUTHOR]

Phenolic compounds in tea plant [Camellia sinensis (L.)] play a crucial role in dominating tea flavor and possess a number of key pharmacological benefits on human health. The present research aimed to study the profile of tissue-specific, development-dependent accumulation pattern of phenolic compounds in tea plant. A total of 50 phenolic compounds were identified qualitatively using liquid chromatography in tandem mass spectrometry technology. Of which 29 phenolic compounds were quantified based on their fragmentation behaviors. Most of the phenolic compounds were higher in the younger leaves than that in the stem and root, whereas the total amount of proanthocyanidins were unexpectedly higher in the root. The expression patterns of 63 structural and regulator genes involved in the shikimic acid, phenylpropanoid, and flavonoid pathways were analyzed by quantitative real-time polymerase chain reaction and cluster analysis. Based on the similarity of their expression patterns, the genes were classified into two main groups: C1 and C2; and the genes in group C1 had high relative expression level in the root or low in the bud and leaves. The expression patterns of genes in C2-2-1 and C2-2-2-1 groups were probably responsible for the development-dependent accumulation of phenolic compounds in the leaves. Enzymatic analysis suggested that the accumulation of catechins was influenced simultaneously by catabolism and anabolism. Further research is recommended to know the expression patterns of various genes and the reason for the variation in contents of different compounds in different growth stages and also in different organs. [ABSTRACT FROM AUTHOR]

The global stability of high arch dam is one of the key problems in the safety study of arch dams, but no feasible method with theoretical basis is available. In this paper, based on the stability theory of mechanical system, it is demonstrated that the global failure of high arch dams belongs to a physical instability starting from local strength failure, which is the extreme point instability according to the characteristics of load-displacement curve obtained from the failure process of dam-foundation system. So the global failure of dam-foundation system should be studied with the stability theory of mechanical system. It is also pointed out that the current stability analysis methods used in engineering are consistent with the stability theory, but not established according to the mechanical system stability theory directly. A perfect method can be obtained through the study of physical disturbance equations. [ABSTRACT FROM AUTHOR]

Tea is a globally consumed non-alcohol beverage with great economic importance. However, lack of the reference genome has largely hampered the utilization of precious tea plant genetic resources towards breeding. To address this issue, we previously generated a high-quality reference genome of tea plant using Illumina and PacBio sequencing technology, which produced a total of 2,124 Gb short and 125 Gb long read data, respectively. A hybrid strategy was employed to assemble the tea genome that has been publicly released. We here described the data framework used to generate, annotate and validate the genome assembly. Besides, we re-predicted the protein-coding genes and annotated their putative functions using more comprehensive omics datasets with improved training models. We reassessed the assembly and annotation quality using the latest version of BUSCO. These data can be utilized to develop new methodologies/tools for better assembly of complex genomes, aid in finding of novel genes, variations and evolutionary clues associated with tea quality, thus help to breed new varieties with high yield and better quality in the future. Design Type(s) sequence assembly objective • sequence annotation objective Measurement Type(s) whole genome sequencing assay • BAC • transcription profiling assay Technology Type(s) DNA sequencing • RNA sequencing Factor Type(s) developmental stage Sample Characteristic(s) Camellia sinensis var. sinensis • leaf • apical bud • stem • flower • fruit • root Machine-accessible metadata file describing the reported data (ISA-Tab format) [ABSTRACT FROM AUTHOR]

Dihydroorotate dehydrogenase (DHODH), in the de novo pyrimidine biosynthetic pathway, is the fourth enzyme of pyrimidine synthesis and is used to oxidize dihydroorotate and hence to orotat. We cloned and characterized here the dhod of silkworms, Bombyx mori. The full-length cDNA sequence of dhod is 1339 bp, including an open reading frame (ORF) of 1173 bp that encoded a 390 amino acid protein. And two domains were involved in the Dihydroorotate dehydrogenase amino acid sequence of silkworms, Bombyx mori (BmDHODH), namely a DHO_dh domain and a transmembrane domain in N-termina. The silkworm dhod is expressed throughout development and in nine tissues. Moreover, knockdown of the silkworm dhod gene reduced cell growth and proliferation through G2/M phase cell cycle arrest. Similarly, DHODH inhibitor (leflunomide) also reduced cell growth and proliferation, with a significant decrease of cyclin B and cdk2. DHODH is the fourth enzyme of pyrimidine synthesis, so we also found that leflunomide can inhibit, at least in part, the endomitotic DNA replication in silk glands cells. These findings demonstrate that downregulation of BmDHODH inhibits cell growth and proliferation in silkworm cells, and the endomitotic DNA replication in silk gland cells. [ABSTRACT FROM AUTHOR]

Background: Tea plants [Camellia sinensis (L.) O. Kuntze] can produce one of the three most widely popular non-alcoholic beverages throughout the world. Polyphenols and volatiles are the main functional ingredients determining tea's quality and flavor; however, the biotic or abiotic factors affecting tea polyphenol biosynthesis are unclear. This paper focuses on the molecular mechanisms of sucrose on polyphenol biosynthesis and volatile composition variation in tea plants. Results: Metabolic analysis showed that the total content of anthocyanins, catechins, and proanthocyanidins(PAs) increased with sucrose, and they accumulated most significantly after 14 days of treatment. Transcriptomic analysis revealed 8384 and 5571 differentially expressed genes in 2-day and 14-day sucrose-treated tea plants compared with control-treated plants. Most of the structural genes and transcription factors (TFs) involved in polyphenol biosynthesis were significantly up-regulated after 2d. Among these transcripts, the predicted genes encoding glutathione S-transferase (GST), ATP-binding cassette transporters (ABC transporters), and multidrug and toxic compound extrusion transporters (MATE transporters) appeared up regulated. Correspondingly, ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS/MS) analysis revealed that the content of non-galloylated catechins and oligomeric PAs decreased in the upper-stem and increased in the lower-stem significantly, especially catechin (C), epicatechin (EC), and their oligomeric PAs. This result suggests that the related flavonoids were transported downward in the stem by transporters. GC/MS data implied that four types of volatile compounds, namely terpene derivatives, aromatic derivatives, lipid derivatives, and others, were accumulated differently after in vitro sucrose treatment. Conclusions: Our data demonstrated that sucrose regulates polyphenol biosynthesis in Camellia sinensis by altering the expression of transcription factor genes and pathway genes. Additionally, sucrose promotes the transport of polyphenols and changes the aroma composition in tea plant. [ABSTRACT FROM AUTHOR]

Flavan-3-ols and oligomeric proanthocyanidins (PAs) are the main nutritional polyphenols in green tea (Camellia sinensis), which provide numerous benefits to human health. To date, the regulatory mechanism of flavan-3-ol biosynthesis in green tea remains open to study. Herein, we report the characterization of a C. sinensis tryptophan-aspartic acid repeat protein (CsWD40) that interacts with myeloblastosis (MYB) and basic helix-loop-helix (bHLH) transcription factors (TFs) to regulate the biosynthesis of flavan-3-ols. Full length CsWD40 cDNA was cloned from leaves and was deduced to encode 342 amino acids. An in vitro yeast two-hybrid assay demonstrated that CsWD40 interacted with two bHLH TFs (CsGL3 and CsTT8) and two MYB TFs (CsAN2 and CsMYB5e). The overexpression of CsWD40 in Arabidopsis thaliana transparent testa glabra 1 (ttg1) restored normal trichome and seed coat development. Ectopic expression of CsWD40 alone in tobacco resulted in a significant increase in the anthocyanins of transgenic petals. CsWD40 was then coexpressed with CsMYB5e in tobacco plants to increase levels of both anthocyanins and PAs. Furthermore, gene expression analysis revealed that CsWD40 expression in tea plants could be induced by several abiotic stresses. Taken together, these data provide solid evidence that CsWD40 partners with bHLH and MYB TFs to form ternary WBM complexes to regulate anthocyanin, PA biosynthesis, and trichome development. [ABSTRACT FROM AUTHOR]

In the present study, proanthocyanidins were qualitatively and quantitatively identified using hydrolysis and thiolysis assays, NP-HPLC, HPLC-ESI-MS, MALDI-TOF-MS, 1H-NMR, and 13C-NMR techniques in different organs of tea plants. The results showed that in leaves, the tri-hydroxyl, cis- and galloylated flavan-3-ols were the main monomeric catechins units, and (epi)catechin was found to be the major unit of polymeric flavan-3-ols when the degree of polymerization was greater than five. In roots, the PAs were found to be abundant, and epicatechin formed the predominant extension unit of oligomeric and polymeric PAs. In order to understand the mechanism of proanthocyanidins polymerization, auto-condensation of the flavan-3-ols was investigated. The results showed that the same trimers (m/z 865) were detected in the extracts of tea plants and in the non-enzymatic in vitro assay, in weak acid as well as weak alkaline solutions at room temperature, when the substrates used were either procyanidin B2 and monomeric flavan-3-ols (epicatechin or catechin), or only procyanidin B2. This suggested that procyanidin B2 not only released carbocation as electrophilic upper units, but also could be used as nucleophilic lower units directly itself, to form the procyanidin trimer in vitro or in vivo. [ABSTRACT FROM AUTHOR]