Pathogen-induced methylglyoxal negatively regulates rice bacterial blight resistance by inhibiting OsCDR1 protease activity

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB), a globally devastating disease of rice (Oryza sativa) that is responsible for significant crop loss. Sugars and sugar metabolites are important for pathogen infection, providing energy and regulating events associated with defense responses; however, the mechanisms by which they regulate such events in BB are unclear. As an inevitable sugar metabolite, methylglyoxal (MG) is involved in plant growth and responses to various abiotic stresses, but the underlying mechanisms remain enigmatic. Whether and how MG functions in plant biotic stress responses is almost completely unknown. Here, we report that the Xoo strain PXO99 induces OsWRKY62.1 to repress transcription of OsGLY II genes by directly binding to their promoters, resulting in overaccumulation of MG. MG negatively regulates rice resistance against PXO99: osglyII2 mutants with higher MG levels are more susceptible to the pathogen, whereas OsGLYII2-overexpressing plants with lower MG content show greater resistance than the wild type. Overexpression of OsGLYII2 to prevent excessive MG accumulation confers broad-spectrum resistance against the biotrophic bacterial pathogens Xoo and Xanthomonas oryzae pv. oryzicola and the necrotrophic fungal pathogen Rhizoctonia solani, which causes rice sheath blight. Further evidence shows that MG reduces rice resistance against PXO99 through CONSTITUTIVE DISEASE RESISTANCE 1 (OsCDR1). MG modifies the Arg97 residue of OsCDR1 to inhibit its aspartic protease activity, which is essential for OsCDR1-enhanced immunity. Taken together, these findings illustrate how Xoo promotes infection by hijacking a sugar metabolite in the host plant.

Whole-body aging mediates the association between exposure to volatile organic compounds and osteoarthritis among U.S. middle-to-old-aged adults

BACKGROUND

Humans are constantly exposed to various volatile organic compounds (VOCs) because of their widespread sources and characteristic of easy evaporation. Existing evidence regarding the association between VOC exposure and osteoarthritis (OA) risk is limited.

PURPOSE

This study aimed to investigate the associations between individual urinary VOC metabolites (VOCMs) and the VOCM mixture, representing internal exposure levels of VOCs, with prevalent OA risk and to explore the mediating effect of aging and oxidative stress (OS) in these associations.

METHODS

Data from the National Health and Nutrition Examination Surveys 2005-2020 were analyzed. Weighted generalized linear regression was employed to explore the associations between individual VOCMs and OA risk, as well as aging and OS biomarkers. A five-repeated ten-fold cross-validation elastic net model was used to identify critical VOCMs for the weight quantile sum (WQS) analysis, which was performed to explore the VOCM mixture and OA risk association. Parallel and serial mediation analyses were conducted to identify the potential mediators and mediation pathways.

RESULTS

This study included 6578 American adults aged ≥40 years, among whom 1052 (16.0 %) individuals reported prevalent OA. Urinary levels of N-acetyl-S-(benzyl)-L-cysteine, mandelic acid and phenylglyoxylic acid were positively associated with OA risk. Eleven VOCMs with nonzero coefficients were identified and included in the WQS analysis, and results revealed an average increase of 24.4 % in OA risk (OR = 1.244, 95 % CI: 1.041, 1.486) per one-quantile increment in the VOCM mixture. Two aging biomarkers, phenotypic age and biological age, parallelly mediated the association between the VOCM mixture and OA risk, with mediation effect proportions of 9.0 % and 16.4 %, respectively.

CONCLUSIONS

Exposure to VOCs is associated with an increased OA risk in middle-to-old aged American adults. The mediating effect of aging contributes to the association between co-exposure to VOCs and OA risk. Further prospective studies are required to substantiate these findings.

Hydrogen sulfide alleviates osmotic stress-induced root growth inhibition by promoting auxin homeostasis

Hydrogen sulfide (H₂ S) promotes plant tolerance against various environmental cues, and d-cysteine desulfhydrase (DCD) is an enzymatic source of H₂ S to enhance abiotic stress resistance. However, the role of DCD-mediated H₂ S production in root growth under abiotic stress remains to be further elucidated. Here, we report that DCD-mediated H₂ S production alleviates osmotic stress-mediated root growth inhibition by promoting auxin homeostasis. Osmotic stress up-regulated DCD gene transcript and DCD protein levels and thus H₂ S production in roots. When subjected to osmotic stress, a dcd mutant showed more severe root growth inhibition, whereas the transgenic lines DCDox overexpressing DCD exhibited less sensitivity to osmotic stress in terms of longer root compared to the wild-type. Moreover, osmotic stress inhibited root growth through repressing auxin signaling, whereas H₂ S treatment significantly alleviated osmotic stress-mediated inhibition of auxin. Under osmotic stress, auxin accumulation was increased in DCDox but decreased in dcd mutant. H₂ S promoted auxin biosynthesis gene expression and auxin efflux carrier PIN-FORMED 1 (PIN1) protein level under osmotic stress. Taken together, our results reveal that mannitol-induced DCD and H₂ S in roots promote auxin homeostasis, contributing to alleviating the inhibition of root growth under osmotic stress.

Triphosphate Tunnel Metalloenzyme 2 Acts as a Downstream Factor of ABI4 in ABA-Mediated Seed Germination

Seed germination is a complex process that is regulated by various exogenous and endogenous factors, in which abscisic acid (ABA) plays a crucial role. The triphosphate tunnel metalloenzyme (TTM) superfamily exists in all living organisms, but research on its biological role is limited. Here, we reveal that TTM2 functions in ABA-mediated seed germination. Our study indicates that TTM2 expression is enhanced but repressed by ABA during seed germination. Promoted TTM2 expression in 35S::TTM2-FLAG rescues ABA-mediated inhibition of seed germination and early seedling development and ttm2 mutants exhibit lower seed germination rate and reduced cotyledon greening compared with the wild type, revealing that the repression of TTM2 expression is required for ABA-mediated inhibition of seed germination and early seedling development. Further, ABA inhibits TTM2 expression by ABA insensitive 4 (ABI4) binding of TTM2 promoter and the ABA-insensitive phenotype of abi4-1 with higher TTM2 expression can be rescued by mutation of TTM2 in abi4-1 ttm2-1 mutant, indicating that TTM2 acts downstream of ABI4. In addition, TTM1, a homolog of TTM2, is not involved in ABA-mediated regulation of seed germination. In summary, our findings reveal that TTM2 acts as a downstream factor of ABI4 in ABA-mediated seed germination and early seedling growth.

Salt stress-induced chloroplastic hydrogen peroxide stimulates pdTPI sulfenylation and methylglyoxal accumulation

High salinity, an adverse environmental factor affecting about 20% of irrigated arable land worldwide, inhibits plant growth and development by causing oxidative stress, damaging cellular components, and disturbing global metabolism. However, whether and how reactive oxygen species disturb the metabolism of salt-stressed plants remain elusive. Here, we report that salt-induced hydrogen peroxide (H2O2) inhibits the activity of plastid triose phosphate isomerase (pdTPI) to promote methylglyoxal (MG) accumulation and stimulates the sulfenylation of pdTPI at cysteine 74. We also show that MG is a key factor limiting the plant growth, as a decrease in MG levels completely rescued the stunted growth and repressed salt stress tolerance of the pdtpi mutant. Furthermore, targeting CATALASE 2 into chloroplasts to prevent salt-induced overaccumulation of H2O2 conferred salt stress tolerance, revealing a role for chloroplastic H2O2 in salt-caused plant damage. In addition, we demonstrate that the H2O2-mediated accumulation of MG in turn induces H2O2 production, thus forming a regulatory loop that further inhibits the pdTPI activity in salt-stressed plants. Our findings, therefore, illustrate how salt stress induces MG production to inhibit the plant growth.

[Establishment and behavioral evaluation of a mouse model of long-term free-choice alcohol drinking]

OBJECTIVE

To establish a model of long-term free drinking mouse by feeding mice with alcohol to simulate the state of human voluntary long-term drinking, and on this basis, to further discuss the evaluation criteria of long-term free drinking mice model in sports, anxiety and cognitive behavior.

METHODS

Forty six-week-old SPF C57BL/6 male mouse were randomly divided into two groups: Long-term free drinking group (n=20) and normal control group (n=20). The two groups were given solid feed normally. The long-term free drinking group was free to take 10% alcohol and water every day, while the normal drinking group only took water every day. The mice were fed for 7 months, and were evaluated by a series of behavioral methods, including Rota-rod test, balance beam test, open filed test, the elevated plus maze, two-box social behavior, new object recognition, Y maze and water maze.

RESULTS

With the increase of drinking days, the mice showed significant alcohol addiction in the alcohol preference test. With the increase of alcohol intake, the mice in the long-term free choice drinking group had slightly shiny fur and reduced diet. Compared with the control group, the weight gain began to slow down from the third month, and the weight decreased significantly by the sixth and seventh months (P=0.006, P < 0.001). The mice showed reduced balance locomotion ability (P=0.003, P=0.001) in the rotary bar and balance beam test. In the open field and elevated cross test, the mice had obvious anxiety-like behavior (P < 0.001). The mice showed decreased social ability in the two boxes of social behavior (P < 0.016). In the experiment of new object recognition and Y maze, the exploration of new object decreased (P=0.018, P=0.040). In the water maze, cognitive functions, such as learning and spatial memory were reduced (P < 0.001).

CONCLUSION

The successful establishment of the long-term free drinking mouse model is more convenient for us to carry out further research on the neural mechanism of alcohol addiction, and lays an experimental foundation for exploring the neural mechanism of alcohol addiction and related new targets.

New insights into the impact of microbiome on horizontal and vertical transmission of a tick-borne pathogen

BACKGROUND

The impact of host skin microbiome on horizontal transmission of tick-borne pathogens , and of pathogen associated transstadial and transovarial changes in tick microbiome are largely unknown, but are important to control increasingly emerging tick-borne diseases worldwide.

METHODS

Focusing on a rickettsiosis pathogen, Rickettsia raoultii, we used R. raoultii-positive and R. raoultii-negative Dermacentor spp. tick colonies to study the involvement of skin microbiota in cutaneous infection with rickettsiae in laboratory mice, and the function of the tick microbiome on maintenance of rickettsiae through all tick developmental stages (eggs, larvae, nymphs, adults) over two generations.

RESULTS

We observed changes in the skin bacteria community, such as Chlamydia, not only associated with rickettsial colonization but also with tick feeding on skin. The diversity of skin microbiome differed between paired tick-bitten and un-bitten sites. For vertical transmission, significant differences in the tick microbiota between pathogenic rickettsia-positive and -negative tick chorts was observed across all developmental stages at least over two generations, which appeared to be a common pattern not only for R. raoultii but also for another pathogenic species, Candidatus Rickettsia tarasevichiae. More importantly, bacterial differences were complemented by functional shifts primed for genetic information processing during blood feeding. Specifically, the differences in tick microbiome gene repertoire between pathogenic Rickettsia-positive and -negative progenies were enriched in pathways associated with metabolism and hormone signals during vertical transmission.

CONCLUSIONS

We demonstrate that host skin microbiome might be a new factor determining the transmission of rickettsial pathogens through ticks. While pathogenic rickettsiae infect vertebrate hosts during blood-feeding by the tick, they may also manipulate the maturation of the tick through changing the functional potential of its microbiota over the tick's life stages. The findings here might spur the development of new-generation control methods for ticks and tick-borne pathogens. Video Abstract.

Skin infectome of patients with a tick bite history

Introduction

Ticks are the most important obligate blood-feeding vectors of human pathogens. With the advance of high-throughput sequencing, more and more bacterial community and virome in tick has been reported, which seems to pose a great threat to people.

Methods

A total of 14 skin specimens collected from tick-bite patients with mild to severe symptoms were analyzed through meta-transcriptomic sequencings.

Results

Four bacteria genera were both detected in the skins and ticks, including Pseudomonas, Acinetobacter, Corynebacterium and Propionibacterium, and three tick-associated viruses, Jingmen tick virus (JMTV), Bole tick virus 4 (BLTV4) and Deer tick mononegavirales-like virus (DTMV) were identified in the skin samples. Except of known pathogens such as pathogenic rickettsia, Coxiella burnetii and JMTV, we suggest Roseomonas cervicalis and BLTV4 as potential new agents amplified in the skins and then disseminated into the blood. As early as 1 day after a tick-bite, these pathogens can transmit to skins and at most four ones can co-infect in skins.

Discussion

Advances in sequencing technologies have revealed that the diversity of tick microbiome and virome goes far beyond our previous understanding. This report not only identifies three new potential pathogens in humans but also shows that the skin barrier is vital in preventing horizontal transmissions of tick-associated bacteria or virus communities to the host. It is the first research on patients' skin infectome after a tick bite and demonstrates that more attention should be paid to the cutaneous response to prevent tick-borne illness.

CK2 promotes jasmonic acid signaling response by phosphorylating MYC2 in Arabidopsis

Jasmonic acid (JA) signaling plays a pivotal role in plant development and defense. MYC2 is a master transcription factor in JA signaling, and was found to be phosphorylated and negatively regulated by MAP kinase and receptor-like kinase. However, the kinases that positively regulate MYC2 through phosphorylation and promote MYC2-mediated activation of JA response have not been identified. Here, we identified CK2 as a kinase that phosphorylates MYC2 and thus regulates the JA signaling. CK2 holoenzyme can interact with MYC2 using its regulatory subunits and phosphorylate MYC2 at multiple sites with its catalytic subunits. Inhibition of CK2 activity in a dominant-negative plant line, CK2mut, repressed JA response. On the other hand, increasing CK2 activity by overexpression of CKB4, a regulatory subunit gene of CK2, enhanced JA response in a MYC2-dependent manner. Substitution of the Ser and Thr residues at phosphorylation sites of MYC2 by CK2 with Ala impaired MYC2 function in activating JA response. Further investigations evidenced that CK2 facilitated the JA-induced increase of MYC2 binding to the promoters of JA-responsive genes in vivo. Our study demonstrated that CK2 plays a positive role in JA signaling, and reveals a previously undiscovered mechanism that regulates MYC2 function.

Olfactory Gene Families in Scopula subpunctaria and Candidates for Type-II Sex Pheromone Detection

Scopula subpunctaria, an abundant pest in tea gardens, produce type-II sex pheromone components, which are critical for its communicative and reproductive abilities; however, genes encoding the proteins involved in the detection of type-II sex pheromone components have rarely been documented in moths. In the present study, we sequenced the transcriptomes of the male and female S. subpunctaria antennae. A total of 150 candidate olfaction genes, comprising 58 odorant receptors (SsubORs), 26 ionotropic receptors (SsubIRs), 24 chemosensory proteins (SsubCSPs), 40 odorant-binding proteins (SsubOBPs), and 2 sensory neuron membrane proteins (SsubSNMPs) were identified in S. subpunctaria. Phylogenetic analysis, qPCR, and mRNA abundance analysis results suggested that SsubOR46 may be the Orco (non-traditional odorant receptor, a subfamily of ORs) of S. subpunctaria. SsubOR9, SsubOR53, and SsubOR55 belonged to the pheromone receptor (PR) clades which have a higher expression in male antennae. Interestingly, SsubOR44 was uniquely expressed in the antennae, with a higher expression in males than in females. SsubOBP25, SsubOBP27, and SsubOBP28 were clustered into the moth pheromone-binding protein (PBP) sub-family, and they were uniquely expressed in the antennae, with a higher expression in males than in females. SsubOBP19, a member of the GOBP2 group, was the most abundant OBP in the antennae. These findings indicate that these olfactory genes, comprising five candidate PRs, three candidate PBPs, and one candidate GOBP2, may be involved in type II sex pheromone detection. As well as these genes, most of the remaining SsubORs, and all of the SsubIRs, showed a considerably higher expression in the female antennae than in the male antennae. Many of these, including SsubOR40, SsubOR42, SsubOR43, and SsubIR26, were more abundant in female antennae. These olfactory and ionotropic receptors may be related to the detection of host plant volatiles. The results of this present study provide a basis for exploring the olfaction mechanisms in S. subpunctaria, with a focus on the genes involved in type II sex pheromones. The evolutionary analyses in our study provide new insights into the differentiation and evolution of lepidopteran PRs.

Dermacentor silvarum, a Medically Important Tick, May Not Be a Competent Vector to Transmit Jingmen Tick Virus

Background: Jingmen tick virus (JMTV) has attracted great attention due to its potential pathogenicity in humans and its transmission by ticks. Dermacentor silvarum (D. silvarum) is one of the dominant tick species in northeastern China, and can transmit many pathogens to humans and animals. However, there have been no report of transmission of JMTV by D. silvarum. Materials and Methods: Ticks were collected from vegetation at the Aershan Port in Inner Mongolia in April 2019. And we do attempt to infect D. silvarum with JMTV by the immersion technique in laboratory conditions. The transmission of JMTV was examined by reverse transcriptase PCR, fluorescence in situ hybridization, and indirect immunofluorescence assay. Statistical analysis was performed using SPSS 24.0. Results: We found that JMTV may only be maintained in the tick without replication, and could not be transmitted to a host following transstadial transmission. Moreover, no virus colonization was found in the midgut or salivary glands of unfed D. silvarum; therefore, D. silvarum may not be susceptible to JMTV infection and therefore unlikely to carry and transmit JMTV. Conclusion: Our study has to some extent filled the knowledge gap regarding the possibility of JMTV transmission by a medically important tick vector, D. silvarum.

Research on the impact of bank comxpetition on stability-Empirical evidence from 4631 banks in US

This paper systematically analyzes the impact mechanism of bank competition on stability. We select the balanced panel data of 4,631 non-failure banks from 2002 to 2017 released by FDIC to do the estimation and then make an appraisal on bank competition with Lerner index and two kinds of Z-score to measure bank stability respectively. The 2SLS with fixed effect is applied for estimation. Our results suggest that: (1) Competition is a living environment for all industries and bank competition mainly affects stability through franchise value, the cost of borrowing and operating behavior. (2)According to the overall regression, we find that there is an inverted U-shaped relationship between bank competition and stability with an inflection point where the Lerner index is about 0.35. Generally, the US banking industry has always been in a state of excessive competition during the observed period. The further analysis of 3 stages indicates that excessive bank competition, an 'invisible hand', may be one of the most important factors triggering the financial crisis. (3) According to the regression on regions, the inverted U-shaped relationship between bank competition and stability is also existing and the inflection point of Lerner index is between 0.3 and 0.37. However, there is also some regional heterogeneity in terms of the degree of competition, the level of stability and the ability to resist risks and maintain stability when facing competition. This paper may help financial regulators and commercial banks formulate differentiate regulatory policies and business strategies so that banks can control risks better and enhance stability in different competitive environments.

Virome and Blood Meal-Associated Host Responses in Ixodes persulcatus Naturally Fed on Patients

The long-lasting co-evolution of ticks with pathogens results in mutual adaptation. Blood-feeding is one of the critical physiological behaviors that have been associated with the tick microbiome; however, most knowledge was gained through the study of laboratory-reared ticks. Here we detached Ixodes persulcatus ticks at different stages of blood-feeding from human patients and performed high-throughput transcriptomic analysis on them to identify their virome and genes differentially expressed between flat and fully fed ticks. We also traced bloodmeal sources of those ticks and identified bats and three other potential mammalian hosts, highlighting the public health significance. We found Jingmen tick virus and 13 putative new viruses belonging to 11 viral families, three of which even exhibited high genetic divergence from viruses previously reported in the same tick species from the same geographic region. Furthermore, differential expression analysis suggested a downregulation of antioxidant genes in the fully fed I. persulcatus ticks, which might be related to bloodmeal-related redox homeostasis. Our work highlights the significance of active surveillance of tick viromes and suggests a role of reactive oxygen species (ROS) in modulating changes in the microbiome during blood-feeding.

Improved molecular softness of tadalafil hapten enhancing antibody performance in immunoassay: Evidence from computational chemistry

The tadalafil-like compounds have appeared recently as adulterants in drinks and healthcare dietary supplements sourced from medicinal and edible food, which may cause illness and even death. In this work, the rationality of haptens was explored by computational chemistry and molecular simulation theories such as frontier molecular orbital (FMO)-based softness (S), three-dimensional (3D) structure, surface electrostatic potential (ESP), and lipophilic potential (LP). An antiserum from hapten H5 with the highest softness and maintaining the appropriate three-dimensional (3D) structure showed the optimal immunoassay performance, indicating an increasing softness was a critical factor for effective hapten. Based on the antibody induced by hapten H5, an indirect competitive enzyme-linked immunosorbent assay (icELISA) method for detecting multiple tadalafil-like adulterants was established. The icELISA showed a limit of detection (LOD), 50% inhibition concentration (IC₅₀ ), and a working range of 0.004-0.396, 0.89-4.27, and 0.094-16.71 ng/ml for tadalafil, amino tadalafil, acetamino tadalafil, nortadalafil, and N-desmethyl ent-tadalafil, respectively. The spiked recoveries of tadalafil-like adulterants in samples ranged from 84.9% to 116.2%. The results of the icELISA and HPLC-MS/MS methods had a good correlation for real samples with the R² of 0.9955. Specially, this work not only provided a convenient immunoassay method for measuring tadalafil-like adulterants in spirit drinks and dietary supplements in group-screening manner, but also suggested that softness was likely to be a general theory for rational hapten design. PRACTICAL APPLICATION: Rapid monitoring of tadalafil-like adulterants in food samples is very necessary and important for consumers, regulatory agencies, and the food industry.

Osmotic stress represses root growth by modulating the transcriptional regulation of PIN-FORMED3

Osmotic stress influences root system architecture, and polar auxin transport (PAT) is well established to regulate root growth and development. However, how PAT responds to osmotic stress at the molecular level remains poorly understood. In this study, we explored whether and how the auxin efflux carrier PIN-FORMED3 (PIN3) participates in osmotic stress-induced root growth inhibition in Arabidopsis (Arabidopsis thaliana). We observed that osmotic stress induces a HD-ZIP II transcription factor-encoding gene HOMEODOMAIN ARABIDOPSIS THALIANA2 (HAT2) expression in roots. The hat2 loss-of-function mutant is less sensitive to osmotic stress in terms of root meristem growth. Consistent with this phenotype, whereas the auxin response is downregulated in wild-type roots under osmotic stress, the inhibition of auxin response by osmotic stress was alleviated in hat2 roots. Conversely, transgenic lines overexpressing HAT2 (Pro35S::HAT2) had shorter roots and reduced auxin accumulation compared with wild-type plants. PIN3 expression was significantly reduced in the Pro35S::HAT2 lines. We determined that osmotic stress-mediated repression of PIN3 was alleviated in the hat2 mutant because HAT2 normally binds to the promoter of PIN3 and inhibits its expression. Taken together, our data revealed that osmotic stress inhibits root growth via HAT2, which regulates auxin activity by directly repressing PIN3 transcription.

PIN3-mediated auxin transport contributes to blue light-induced adventitious root formation in Arabidopsis

Adventitious rooting is a heritable quantitative trait that is influenced by multiple endogenous and exogenous factors in plants, and one important environmental factor required for efficient adventitious root formation is light signaling. However, the physiological significance and molecular mechanism of light underlying adventitious root formation are still largely unexplored. Here, we report that blue light-induced adventitious root formation is regulated by PIN-FORMED3 (PIN3)-mediated auxin transport in Arabidopsis. Adventitious root formation is significantly impaired in the loss-of-function mutants of the blue light receptors, PHOTOROPIN1 (PHOT1) and PHOTOROPIN2 (PHOT2), as well as the phototropic transducer, NON-PHOTOTROPIC HYPOCOTYL3 (NPH3). In addition, blue light enhanced the auxin content in the adventitious root, and the pin3 loss-of-function mutant had a reduced adventitious rooting response under blue light compared to the wild type. The PIN3 protein level was higher in plants treated with blue light than in those in darkness, especially in the hypocotyl pericycle, while PIN3-GFP failed to accumulate in nph3 PIN3::PIN3-GFP. Furthermore, the results showed that PIN3 physically interacted with NPH3, a key transducer in phototropic signaling. Taken together, our study demonstrates that blue light induces adventitious root formation through the phototropic signal transducer, NPH3, which regulates adventitious root formation by affecting PIN3-mediated auxin transport.

Molecular evidence of Candidatus Rickettsia longicornii and a novel Rickettsia strain from ticks in Southern China

Ticks and tick-borne rickettsial diseases have been gaining greater attention in China over the past decade. However, most published studies to date have occurred in Northern China, with limited investigations occurring in China's southern provinces. As part of larger surveillance efforts, a cross-sectional survey was conducted in six sites at Guangdong, Guangxi and Yunnan investigating rickettsial infection in ticks. A total of 581 ticks were collected from hosts and screened via PCR, targeting rrs, gltA, ompB, sca4, and ompA gene fragments. Two of 12 Haemaphysalis formosensis ticks were infected with novel Rickettsia strain GD01, which was closest phylogenetically (97.3-98.9 % identity) to Rickettsia tamurae strain AT-1, but not within the same clade. Another detected strain (GD02) shared similar identity, 99-100 % across four gene targets, to recently detected Candidatus Rickettsia longicornii isolate ROK-HL727, with an overall prevalence of 12.5 % (71/569). The presence of such pathogens calls for increased public health attention and active surveillance in patients reporting recent tick bites.

Large-Scale Comparative Analyses of Tick Genomes Elucidate Their Genetic Diversity and Vector Capacities

Among arthropod vectors, ticks transmit the most diverse human and animal pathogens, leading to an increasing number of new challenges worldwide. Here we sequenced and assembled high-quality genomes of six ixodid tick species and further resequenced 678 tick specimens to understand three key aspects of ticks: genetic diversity, population structure, and pathogen distribution. We explored the genetic basis common to ticks, including heme and hemoglobin digestion, iron metabolism, and reactive oxygen species, and unveiled for the first time that genetic structure and pathogen composition in different tick species are mainly shaped by ecological and geographic factors. We further identified species-specific determinants associated with different host ranges, life cycles, and distributions. The findings of this study are an invaluable resource for research and control of ticks and tick-borne diseases.

Genetic Diversity and Coexistence of Babesia in Ticks (Acari: Ixodidae) from Northeastern China

Background: Human babesiosis is an emerging zoonotic disease transmitted by ticks in China. A few systematic reports on Babesia spp. was involved with ticks, especially in the human babesiosis endemic areas in Northeastern China. Materials and Methods: Ticks were collected from 30 individual waypoints along 2.0 km transects in two recreational forests. Babesia spp. infection in ticks was screened by amplifying the partial 18s rRNA gene with subsequent sequencing. Multivariate logistic regression analysis was used to determine the association between tick infection and related environmental risk factors. Cluster analyses were performed using SaTScan v6.0 software to identify any geographical cluster of infected ticks. Results: A total of 2380 Ixodes persulcatus and 461 Haemaphysalis concinna ticks were collected. Of the 0.97% of I. persulcatus ticks that tested positive, five Babesia species were identified, including B. bigemina (n = 6), B. divergens (n = 2), B. microti (n = 3), B. venatorum (n = 11), and one novel strain HLJ-8. Thirteen (2.92%) H. concinna ticks tested positive for B. bigemina (n = 1), B. divergens (n = 1), three genetic variants of Babesia represented by HLJ-874, which was closely related to Babesia sp.MA#361-1, and eight other Babesia variants represented by HLJ242, which were similar to B. crassa. Each study site had 5-6 different Babesia spp. One waypoint was more likely to yield B. venatorum (relative risk = 15.36, p = 0.045) than all other waypoints. Conclusions: There exists a high genetic diversity of Babesia spp. across a relatively small sampled region. Further study is needed to understand the risks these variants pose to human health.

Anaplasma platys-Like Infection in Goats, Beijing, China

As one of the important tick-borne zoonotic pathogens, Anaplasma has both veterinary and public health significance. Here, we performed a survey of Anaplasma infection in the goats from a farm in Beijing, China, and found 44.6% (41/92) were infected with Anaplasma capra, and 22.8% (21/92) were infected with Anaplasma sp. This Anaplasma sp. bacterium was close to a recently emerging Anaplasma platys strain based on gltA and groEL gene phylogenetic analysis. As to further understand the characteristics of Anaplasma sp., we raised a couple of positive goats (n = 2) in the laboratory with tick-free settings. We observed inappetence, vomiting, high fever, and weakness of limbs in the goat's offspring (n = 3). In addition, the blood samples from all offspring were all positive of this Anaplasma spp. We did not see any intracellular morulae in neutrophils, monocytes, and erythrocytes, but we identified some in the platelets of the blood smears from the positive goats by light microscopy. We named it A. platys-like and suggested it may infect platelets and be transmitted vertically through the placenta of goats. These findings deserve further evaluation.

Characterization of Microbial Communities in Ixodes persulcatus (Ixodida: Ixodidae), a Veterinary and Medical Important Tick Species in Northeastern China

The importance of ticks in veterinary and medical science has received much attention. The dominant tick species in northeastern China, Ixodes persulcatus tick can transmit various pathogens to humans and animals and there are some studies on the microbiome composition of this tick. Our study characterized the bacterial communities in I. persulcatus by 16S amplicon pyrosequencing and described the differences of microorganisms in male and female tick and assessed the variation of microorganisms in the development stages in northeastern China. We mainly found the following bacteria genera: Pseudomonas (Pseudomonadales: Pseudomonadaceae), Citrobacter (Enterobacteriales: Enterobacteriaceae), and Rickettsia (Rickettsiales: Rickettsiaceae). Rickettsia is common and harmful pathogen transmitted by ticks. Meanwhile, we found there were differences between male and female tick of microbiomes, and the diversity of microbiome increased from engorged female ticks to eggs, but decreased when the eggs were molting into larvae. Our data showed that male ticks exhibited greater microbial diversity than female I. persulcatus tick and larvae presented with a different bacterial community compared to engorged female tick and hatched eggs. These findings may be useful for further understanding the interaction between I. persulcatus and microbiome biology.

Identifying SARS-CoV-2-related coronaviruses in Malayan pangolins

The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-2¹. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection². Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.

WRKY13 Enhances Cadmium Tolerance by Promoting D-CYSTEINE DESULFHYDRASE and Hydrogen Sulfide Production

Hydrogen sulfide (H₂S), a plant gasotransmitter, functions in the plant response to cadmium (Cd) stress, implying a role for cysteine desulfhydrase in producing H₂S in this process. Whether d -CYSTEINE DESULFHYDRASE (DCD) acts in the plant Cd response remains to be identified, and if it does, how DCD is regulated in this process is also unknown. Here, we report that DCD-mediated H₂S production enhances plant Cd tolerance in Arabidopsis (Arabidopsis thaliana). When subjected to Cd stress, a dcd mutant accumulated more Cd and reactive oxygen species and showed increased Cd sensitivity, whereas transgenic lines overexpressing DCD had decreased Cd and reactive oxygen species levels and were more tolerant to Cd stress compared with wild-type plants. Furthermore, the expression of DCD was stimulated by Cd stress, and this up-regulation was mediated by a Cd-induced transcription factor, WRKY13, which bound to the DCD promoter. Consistently, the higher Cd sensitivity of the wrky13-3 mutant was rescued by the overexpression of DCD Together, our results demonstrate that Cd-induced WRKY13 activates DCD expression to increase the production of H₂S, leading to higher Cd tolerance in plants.

Identifying SARS-CoV-2-related coronaviruses in Malayan pangolins

The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-2¹. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection². Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.

[Association between osteoporosis and severe periodontal attachment loss in postmenopausal women]

Objective: To investigate the association between osteoporosis and severe periodontal attachment loss in postmenopausal women. Methods: One hundred and ninety-five postmenopausal women aged 50-65 years old were included in the present study. The participant were recruited from patients in the Peking University International Hospital and through website from March, 2017 to August, 2018. Periodontal examination, filling out a structured questionnaire and bone mass density (BMD) examination were completed to each of the participants. The clinical attachment loss (CAL), oral hygiene index simplified (OHI-S), and bleeding on probing (BOP) were examined and recorded as periodontal parameters. The structured questionnaire was used to collect information of the physical activity, socioeconomic status, marital status, oral health habits, and so on. Bone mass density of the lumbar spine and left hip were scanned by using standardized dual energy X-ray absorptiometry. Based on the T-score of BMD (difference between the measured BMD and the mean value of young white women in terms of standard deviations), osteoporosis was defined as T-score≤-2.5 (according to the World Health Organization criteria). Fourteen risk factors were preliminarily screened by chi-square test, including age, duration of menopause, body mass index (BMI), exercise habit, economic status, marital status, level of education, habit of dental visit, tooth brushing habit, usage of interdental tools, OHI-S, BOP(+)%, osteoporosis in hip and osteoporosis in lumbar. Factors with P<0.05 were selected for multivariate Logistic regression analysis. Logistic regression was used to analysis the risk factors of severe periodontal attachment loss. Results: The mean age of 195 postmenopausal women was (57.8±4.3) years. After adjusting for ages, the economic status, habit of dental visit, OHI-S and BOP(+)%, there was an association of osteoporosis in hip and severe periodontal attachment loss in postmenopausal women [odds ratios (OR)=2.466, 95% confidence intervals (CI) was 1.173-5.185, P=0.017]. Conclusions: Postmenopausal women with osteoporosis in hip has a greater chance of presenting severe periodontal attachment loss.

Auxin abolishes SHI-RELATED SEQUENCE5-mediated inhibition of lateral root development in Arabidopsis

Lateral roots (LRs), which form in the plant postembryonically, determine the architecture of the root system. While negative regulatory factors that inhibit LR formation and are counteracted by auxin exist in the pericycle, these factors have not been characterised. Here, we report that SHI-RELATED SEQUENCE5 (SRS5) is an intrinsic negative regulator of LR formation and that auxin signalling abolishes this inhibitory effect of SRS5. Whereas LR primordia (LRPs) and LRs were fewer and less dense in SRS5ox and Pro35S:SRS5-GFP plants than in the wild-type, they were more abundant and denser in the srs5-2 loss-of-function mutant. SRS5 inhibited LR formation by directly downregulating the expression of LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16) and LBD29. Auxin repressed SRS5 expression. Auxin-mediated repression of SRS5 expression was not observed in the arf7-1 arf19-1 double mutant, likely because ARF7 and ARF19 bind to the promoter of SRS5 and inhibit its expression in response to auxin. Taken together, our data reveal that SRS5 negatively regulates LR formation by repressing the expression of LBD16 and LBD29 and that auxin releases this inhibitory effect through ARF7 and ARF19.

First Confirmed Infection of Candidatus Rickettsia Tarasevichiae in Rodents Collected from Northeastern China

Background: To date, there have been few investigations on Candidatus Rickettsia tarasevichiae in rodents carried out in China. In this study, we conducted surveillance for Candidatus R. tarasevichiae infection in rodents. A total of 463 rodents were captured at five survey sites in Mudanjiang, Heilongjiang province, where Candidatus R. tarasevichiae patients have been reported. PCR targeting citrate synthase and outer membrane protein genes was performed and positive amplicons were sequenced. Result: Candidatus R. tarasevichiae was detected in 1.29% of the 463 rodents sampled from the five survey sites in Mudanjiang, Heilongjiang province. Only 2 out of 13 (15.38%) Rattus norvegicus and 4 out of 80 (5%) Clethrionomys rufocanus collected from Dashigou forestry were positive for the gltA and ompA genes of Candidatus R. tarasevichiae DNA. The detected Candidatus R. tarasevichiae was in the same clade of sequences from patients in Mudanjiang based on phylogenetic analysis. Conclusion: Rodents are major host of ticks and also serve as reservoirs of spotted fever group (SFG) Rickettsia. Although this is the first confirmation of Candidatus R. tarasevichiae detected in rodents in China, further investigations are needed to clarify the distribution of Candidatus R. tarasevichiae in rodents elsewhere and what role they play as reservoirs.

[Serum status and their changes of some vitamin substances and homocysteine in healthy subjects in Beijing]

Objective: To investigate serum status of folate, vitamin B(12), homocysteine (Hcy) and hydroxyvitamin D (25OHD) and their trends in different gender and age groups. Methods: This was a cross-sectional study. The enrolled subjects were those received medical examination in Beijing Hospital from September to November 2018 and were identified as appeared healthy persons. 1220 subjects were recruited and were divided into groups of young and middle age group (30-49 years, 50-59 years) and the elderly group (60-69 years, 70-79 years and ≥80 years). We measured folate, vitamin B(12), and 25OHD using electrochemiluminescence by chemiluminescence immunoassay. Hcy was measured by autobiochemical analyzer. Results: Total folate levels in male and female subjects were 7.16 (4.74-10.75) and 9.17 (6.49-13.55) μg/L respectively. Total vitamin B(12) levels in the male and female were 505.60 (386.80-700.90) and 582.60 (430.70-846.98) ng/L respectively. Hcy levels were 14.68 (12.25-18.58) and 11.29 (9.65-13.58) μmol/L. 25OHD levels were 21.60 (16.40-28.70) and 16.80 (12.30-24.15) μg/L respectively. Total folate and vitamin B(12) levels in female were higher than that in male subjects (Z=-7.796, -4.772, P<0.001). However, total Hcy and 25OHD levels in male were higher than that in female subjects (Z=-15.230, -8.447, P<0.001). Comparing with the substances in the above age groups, folate level in the elderly was lower than that in the younger age and middle age groups.However, vitamin B(12), 25OHD and Hcy levels were higher in the elderly groups. Furthermore, the levels of folate, vitamin B(12) and 25OHD were getting higher in the group of ≥80 years female compared with the rest of the age groups, but it turned lower in the male group of ≥80 years. Conclusions: There are some differences in the serum values of folate, vitamin B(12), Hcy and 25OHD among various age groups as well as between males and females. These should be considered in the development of national reference ranges.

The COP1 Target SHI-RELATED SEQUENCE5 Directly Activates Photomorphogenesis-Promoting Genes

Plant seedlings undergo distinct developmental processes in the dark and in the light. Several genes, including ELONGATED HYPOCOTYL5 (HY5), B-BOX PROTEIN21 (BBX21), and BBX22, have been identified as photomorphogenesis-promoting factors in Arabidopsis thaliana; however, the overexpression of these genes does not induce photomorphogenesis in the dark. Using an activation-tagging approach, we identified SRS5ox, which overexpresses SHI-RELATED SEQUENCE5 (SRS5) following induction with estradiol. SRS5 overexpression in SRS5ox and Pro35S:SRS5-GFP seedlings results in a constitutive photomorphogenesis phenotype in the dark, whereas SRS5 loss of function in the srs5-2 mutant results in long hypocotyls in the light. This indicates that SRS5 is a positive regulator of photomorphogenesis. Furthermore, SRS5 promotes photomorphogenesis by directly binding to the promoters of photomorphogenesis-promoting genes, such as HY5, BBX21, and BBX22, and activating their expression, thus affecting the expression of downstream light-signaling genes. These data indicate that SRS5 acts in the upregulation of photomorphogenesis-promoting genes. In addition, CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1), which plays a central repressive role in seedling photomorphogenesis, directly ubiquitinates SRS5, promoting its degradation in the dark. Taken together, our results demonstrate that SRS5 directly activates the expression of downstream genes HY5, BBX21, and BBX22 and is a target of COP1-mediated degradation in Arabidopsis.

SORTING NEXIN 1 Functions in Plant Salt Stress Tolerance Through Changes of NO Accumulation by Regulating NO Synthase-Like Activity

Nitric oxide (NO) production via NO synthase (NOS) plays a vital role in plant tolerance to salt stress. However, the factor(s) regulating NOS-like activity in plant salt stress tolerance remains elusive. Here, we show that Arabidopsis SORTING NEXIN 1 (SNX1), which can restore H₂O₂-induced NO accumulation in yeast Δsnx4 mutant, functions in plant salt stress tolerance. Salt stress induced NO accumulation through promoted NOS-like activity in the wild type, but this induction was repressed in salt-stressed snx1-2 mutant with the mutation of SNX1 because NOS-like activity was inhibited in the mutant. Consistently, snx1-2 displayed reduced tolerance to high salinity with decreased survival rate compared with the wild type, and exogenous treatment with NO donor significantly rescued the hypersensitivity of the mutant to salt stress. In addition, the snx1-2 mutant with reduced NOS-like activity repressed the expression of stress-responsive genes, decreased proline accumulation and anti-oxidant ability compared with wild-type plants when subjected to salt stress. Taken together with our finding that salt induces the expression of SNX1, our results reveal that SNX1 plays a crucial role in plant salt stress tolerance by regulating NOS-like activity and thus NO accumulation.

[Significance of Simultaneous Analysis of Bone Marrow Smear and Bone Marrow Biopsy in the Diagnosis of Lymphoma]

OBJECTIVE

To explore the value of bone marrow smear combined with biopsy in the diagnosis of lymphoma.

METHODS

Clinical data of 50 cases of lymphoma from our hospital were analyzed retrospectively, and the results of the bone marrow smear and the bone marrow biopsy were compared simultaneously.

RESULTS

The decision for the degree of bone marrow hyperplasia in bone marrow biopsy slice was superior to that in smear, and the active or highly active hyperplasia of nucleated cells were observed in all the bone marrow biopsies; the lymphomatic cells were observed in bone marrow smear of the 12 patients(24%), but the bone marrow biopsies showed a higher detection rate of lymphomatic cells 44% in 22 patients(P<0.05); The hyperplasia of bone marrow fibrous tissue, mainly mild to moderate, were the common in cases with bone marrow involvement and the severity of bone marrow fibrosis positively correlated with the number of lymphomatic cells.

CONCLUSION

Biopsy combined with aspiration can improve the accuracy of diagnosis in lymphoma with bone marrow involvement.

A role for CK2 β subunit 4 in the regulation of plant growth, cadmium accumulation and H2O2 content under cadmium stress in Arabidopsis thaliana

Protein kinase CK2, which consists of two α and two β subunits, plays an essential role in plant development and is implicated in plant responses to abiotic stresses, including salt and heat. However, the function of CK2 in response to heavy metals such as cadmium (Cd) has not yet been established. In this study, the transgenic line CKB4ox, which overexpresses CKB4 encoding the CK2β subunit and has elevated CK2 activity, was used to investigate the potential role of CK2 in response to Cd stress in Arabidopsis thaliana. Under Cd stress, CKB4ox showed reduced root growth and biomass accumulation as well as decreased chlorophyll and proline contents compared with wild type. Furthermore, increased Cd accumulation and a higher H₂O₂ content were found in CKB4ox, possibly contributing to the inhibition of CKB4ox growth under Cd stress. Additionally, altered levels of Cd and H₂O₂ were found to be associated with decreased expression of genes involved in Cd efflux, Cd sequestration and H₂O₂ scavenging. Taken together, these results suggest that elevated expression of CKB4 and increased CK2 activity enhance the sensitivity of plants to Cd stress by affecting Cd and H₂O₂ accumulation, including the modulation of genes involved in Cd transport and H₂O₂ scavenging. This study provides direct evidence for the involvement of plant CK2 in the response to Cd stress.

Nitric oxide is involved in stomatal development by modulating the expression of stomatal regulator genes in Arabidopsis

As sessile organisms, plants require many flexible strategies to adapt to the environment. Although some environmental signaling pathways regulating stomatal development have been identified, how stomatal regulators are modulated by internal and external signals to determine the final stomatal abundance requires further exploration. In our studies, we found that nitric oxide (NO) promotes stomatal development with increased stomatal index as well as the relative number of meristemoids and guard mother cells [%(M+GMC)] in NO-treated wild-type Arabidopsis plants; this role of NO was further verified in the nox1 mutant, which exhibits higher NO levels, and the noa1 mutant, which exhibits low NO accumulation. To gain insight into the molecular mechanisms underlying the effect of NO, we further assayed the expression of genes involved in stomatal development and found that NO induces the expression of the master regulators SPCH, MUTE and SCRM2 to initiate stomatal development. In addition, MPK6 is also involved in NO-promoted stomatal development, as MPK6 expression was repressed in nox1 and NO-treated plants, and transgenic plants overexpressing MPK6 were less sensitive to SNP treatment in terms of changes in the%(M+GMC). Thus, our study shows that NO promotes the production of stomata by up-regulating the expression of SPCH, MUTE and SCRM2 and down-regulating MPK6 expression.

[Research progress of phytoestrogens-like chemical constituents in natural medicines]

Phytoestrogens, which can bind with estrogen receptor and produce estrogen-like effects, are a kind of nonsteroidal compound in plant. Phytoestrogens chemically include isoflavones, coumarins, lignans and other compounds. Phytoestrogens are selective estrogen receptor modulator, and have therapeutical effects on breast cancer, prostate cancer, cardiovascular disease, menopausal symptoms, osteoporosis and other disease, however, do not produce stimulatory hyperplasia effects on uterus, mammary glands and other tissues and organs with positive estrogen receptor. Long-term exposure or excessive use of phytoestrogens maybe affects male reproductive system and hematopoietic function of fetus. Some questions need to be further studied, such as evaluation criteria on biological activity, adverse effects, and action mechanism of phytoestrogen. This review covers plant sources, chemical structure, pharmacological activity and safety of phytoestrogens. It will provide a useful reference for intensive research and rational utilization the phytoestrogens.

Glucose inhibits root meristem growth via ABA INSENSITIVE 5, which represses PIN1 accumulation and auxin activity in Arabidopsis

Glucose functions as a hormone-like signalling molecule that modulates plant growth and development in Arabidopsis thaliana. However, the role of glucose in root elongation remains elusive. Our study demonstrates that high concentrations of glucose reduce the size of the root meristem zone by repressing PIN1 accumulation and thereby reducing auxin levels. In addition, we verified the involvement of ABA INSENSITIVE 5 (ABI5) in this process by showing that abi5-1 is less sensitive to glucose than the wild type, whereas glucose induces ABI5 expression and the inducible overexpression of ABI5 reduces the size of the root meristem zone. Furthermore, the inducible overexpression of ABI5 in PIN1::PIN1-GFP plants reduces the level of PIN1-GFP, but glucose reduces the level of PIN1-GFP to a lesser extent in abi5-1 PIN1::PIN1-GFP plants than in the PIN1::PIN1-GFP control, suggesting that ABI5 is involved in glucose-regulated PIN1 accumulation. Taken together, our data suggest that ABI5 functions in the glucose-mediated inhibition of the root meristem zone by repressing PIN1 accumulation, thus leading to reduced auxin levels in roots.

Proper PIN1 distribution is needed for root negative phototropism in Arabidopsis

Plants can be adapted to the changing environments through tropic responses, such as light and gravity. One of them is root negative phototropism, which is needed for root growth and nutrient absorption. Here, we show that the auxin efflux carrier PIN-FORMED (PIN) 1 is involved in asymmetric auxin distribution and root negative phototropism. In darkness, PIN1 is internalized and localized to intracellular compartments; upon blue light illumination, PIN1 relocalize to basal plasma membrane in root stele cells. The shift of PIN1 localization induced by blue light is involved in asymmetric auxin distribution and root negative phototropic response. Both blue-light-induced PIN1 redistribution and root negative phototropism is mediated by a BFA-sensitive trafficking pathway and the activity of PID/PP2A. Our results demonstrate that blue-light-induced PIN1 redistribution participate in asymmetric auxin distribution and root negative phototropism.

Blue-light-induced PIN3 polarization for root negative phototropic response in Arabidopsis

Root negative phototropism is an important response in plants. Although blue light is known to mediate this response, the cellular and molecular mechanisms underlying root negative phototropism remain unclear. Here, we report that the auxin efflux carrier PIN-FORMED (PIN) 3 is involved in asymmetric auxin distribution and root negative phototropism. Unilateral blue-light illumination polarized PIN3 to the outer lateral membrane of columella cells at the illuminated root side, and increased auxin activity at the illuminated side of roots, where auxin promotes growth and causes roots bending away from the light source. Furthermore, root negative phototropic response and blue-light-induced PIN3 polarization were modulated by a brefeldin A-sensitive, GNOM-dependent, trafficking pathway and by phot1-regulated PINOID (PID)/PROTEIN PHOSPHATASE 2A (PP2A) activity. Our results indicate that blue-light-induced PIN3 polarization is needed for asymmetric auxin distribution during root negative phototropic response.

A gain-of-function mutation in IAA8 alters Arabidopsis floral organ development by change of jasmonic acid level

Auxin regulates a variety of physiological processes via its downstream factors included Aux/IAAs. In this study, one of these Aux/IAAs, IAA8 is shown to play its role in Arabidopsis development with transgenic plants expressing GFP-mIAA8 under the control of IAA8 promoter, in which IAA8 protein was mutated by changing Pro170 to Leu170 in its conserved domain II. These transgenic dwarfed plants had more lateral branches, short primary inflorescence stems, decreased shoot apical dominance, curled leaves and abnormal flower organs (short petal and stamen, and bent stigmas). Further experiments revealed that IAA8::GFP-mIAA8 plants functioned as gain-of-function mutation to increase GFP-mIAA8 amount probably by stabilizing IAA8 protein against proteasome-mediated protein degradation with IAA8::GFP-IAA8 plants as control. The searching for its downstream factors indicated its interaction with both ARF6 and ARF8, suggesting that IAA8 may involve in flower organ development. This was further evidenced by analyzing the expression of jasmonic acid (JA) biosynthetic genes and JA levels because ARF6 and ARF8 are required for normal JA production. These results indicated that in IAA8::GFP-mIAA8 plants, JA biosynthetic genes including DAD1 (AT2G44810), AOS (AT5G42650) and ORP3 (AT2G06050) were dramatically down-regulated and JA level in the flowers was reduced to 70 % of that in wild-type. Furthermore, exogenous JA application can partially rescue short petal and stamen observed IAA8::GFP-mIAA8 plants. Thus, IAA8 plays its role in floral organ development by changes in JA levels probably via its interaction with ARF6/8 proteins.

The Arabidopsis LFR gene is required for the formation of anther cell layers and normal expression of key regulatory genes

The anther is the male reproductive organ in flowering plants. Although some genes were reported to be involved in anther development, the molecular mechanisms underlying the transcriptional regulation of these genes is unclear. lfr-2 (leaf and flower related-2), the null allele of Arabidopsis thaliana LFR (LEAF AND FLOWER RELATED), was male-sterile. The anthers of lfr-2 plants were defective in sporogenous cell formation, tapetum development, and pollen development. In agreement with these phenotypes, expression studies showed that LFR was expressed in all cell layers of the anther, and that expression was particularly strong in the tapetal cells and pollen grains. Quantitative RT-PCR analysis revealed that LFR is required for the normal transcription of some anther development-related genes, such as AMS, CALS5, and DYT1, MS1 and MS2, and ROXY2. Genetic analysis showed that SPL was epistatic to LFR while LFR was epistatic to DYT1. We propose that LFR may be a crucial component in the regulation of a genetic network that modulates anther development.

Synthesis of isoindolinones via palladium-catalyzed C-H activation of N-methoxybenzamides

The synthesis of isoindolinones from N-methoxybenzamides and alkenes has been achieved by Pd-catalyzed ortho sp(2) C-H activation and intramolecular oxidative amidation, which involve the cleavage of four bonds and formation of two bonds.

[Characteristics of T-cell lineage immunophenotype in 95 patients with acute lymphoid leukemia]

The objective of this study was to investigate the immunophenotype of T-lineage acute lymphoid leukemia (T-ALL) and to find valuable immunologic markers in T-ALL diagnosis and therapy. Four-color multiparametric flow cytometry(FCM) with CD45/SSC gating was used for immunophenotyping of 95 patients with newly diagnosed T-ALL. The results demonstrated that T-ALL occurred more frequently in males younger than 30 years of age and was usually accompanied by a high WBC count and tumor mass at diagnosis. Univariate analysis showed an influence on achievement of CR1 for age (< 30 years) but not for WBC count and tumor mass. According to WHO (2008) classification of tumors of haematopoietic and lymphoid tissues, 87 patients with confirmed subtype included 27 cases of Pro-T-ALL (31.0%), 31 cases of Pre-T-ALL (35.6%), 23 cases of cortical-T-ALL (26.4%), 6 cases of medullary-T-ALL (6.9%). CD34 expression in Pro-T-ALL was significantly higher than that of Pre-T-ALL (p = 0.001). After the first chemotherapy, the complete remission rate in Pro-T-ALL was statistically lower than that of Pre-T-ALL. Besides, the complete remission rate of immature T-ALL (including Pro-T-ALL and Pre-T-ALL) was also significantly lower than that in mature T-ALL (including cortical-T-ALL and medullary-T-ALL). Myeloid antigen (CD13, CD33) expression was associated with T-ALL subtype and treatment effect. While 66.7% of CD13(+) patients belonged to Pre-T-ALL, most (60.0%) of CD33(+) patients were classified into Pro-T-ALL; CD13 expression had no effect on CR1 rate whereas CD33(+) patients had worse treatment effect compared with CD33(-) groups (p = 0.001). Notably, the expression of CD117 reached up to 26.7% and the positive cases were primarily distributed in pro-T-TAll and pre-T-ALL. It is found that CD117 expression in CD34(-) group was homogeneous and CD117 expression level was less than 10% in 73.2% patients, but CD117 expression level in CD34(+) group was not homogenous, in which group the CD117 expression levels < 10%, 10% - 20% and > 20% were 44.2%, 17.3% and 38.5% respectively. As compared with CD34(-) group, the proportion of patients with CD117 expression levels < 10%, > 20% in CD34(+) group was higher, and there was significant difference between these 2 group. It is concluded that immunophenotype has great value in T-ALL diagnosis, classification as well as treatment. Flow cytometry provides access to find valuable immunologic markers for T-ALL biological research.

[Activation of hippocampal D1 dopamine receptor inhibits glutamate-mediated depression induced by chronic unpredictable mild stress in rats]

The present study was to investigate the role of dopamine D1 receptors and its relationship with glutamate, N-methyl-D-aspartic acid (NMDA) receptor and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor in depression induced by chronic unpredictable mild stress (CUMS). CUMS-induced depression model was established in Sprague-Dawley rats, and intrahippocampal microinjections of D1 dopamine receptor agonist SKF38393, non-competitive NMDA receptor antagonist MK-801 and AMPA receptor antagonist NBQX were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by measurement of weight changes, sucrose preference test, open-field test and tail suspension test. The concentration of glutamic acid and the expression of its receptors' subunits were detected by HPLC and Western blot, respectively. The results showed that, compared with control group, CUMS rats showed depression-like behavioral changes, higher concentration of glutamic acid, lower expressions of NMDA receptor (NR1) and AMPA receptor (GluR2/3) in hippocampus. Pretreatment with injection of SKF38393 could rescue such depression effect of CUMS, decrease the concentration of glutamic acid, and increase the expressions of NMDA receptor (NR1), AMPA receptor (GluR2/3) in hippocampus. Pretreatment with MK-801 could enhance the antidepressant effect of SKF38393, while NBQX weakened. These results suggest that agonists of D1 dopamine receptor could reduce the concentration of glutamic acid in hippocampus, and its antidepressant effect may be mediated by AMPA receptor partially.

[Progress in biology of dendritic cells]

As the most potent antigen-presenting cells (APC), dendritic cells are important in launching both humoral and cellular immune responses against tumor. Although the high evaluation of DC in immunotherapy for cancer by means of DC vaccines, more studies have indicated DC is a heterogeneous population and proved that DC subsets are prominent determinants for the effectiveness of immune responses. Different DC subsets display different receptors and surface molecules, and express different sets of cytokines/chemokines, which result in distinct immunological outcomes. Clinical trials with ex vivo generated DC vaccines also manifest unexpected immunological tolerance as well as allergic response. It is essential to study the biological aspects of human DC subsets, which may be a key to the generation of novel DC-based vaccines. In this article, the progress of studies on biology of dendritic cells including their origins, differentiation, function and application of DC subsets is reviewed.

Palladium-catalyzed alkoxylation of N-methoxybenzamides via direct sp2 C-H bond activation

The palladium-catalyzed ortho-alkoxylation of N-methoxybenzamides has been demonstrated. With the CONHOMe group as a directing group, the aromatic C-H bond can be functionalized efficiently to generate ortho-alkoxylated derivatives in moderate to good yields.