Plasma membrane-associated calcium signaling modulates cadmium transport.

Cadmium (Cd) is a toxic heavy element for plant growth and development, and plants have evolved many strategies to cope with Cd stress. However, the mechanisms how plants sense Cd stress and regulate the function of transporters remain very rudimentary. Here, we found that Cd stress induces obvious Ca2+ signals in Arabidopsis roots. Furthermore, we identified the calcium-dependent protein kinases CPK21 and CPK23 that interacted with the Cd transporter NRAMP6 through a variety of protein interaction techniques. Then, we confirmed that the cpk21 23 double mutants significantly enhanced the sensitive phenotype of cpk23 single mutant under Cd stress, while the overexpression and continuous activation of CPK21 and CPK23 enhanced plants tolerance to Cd stress. Multiple biochemical and physiological analyses in yeast and plants demonstrated that CPK21/23 phosphorylate NRAMP6 primarily at Ser489 and Thr505 to inhibit the Cd transport activity of NRAMP6, thereby improving the Cd tolerance of plants. Taken together, we found a plasma membrane-associated calcium signaling that modulates Cd tolerance. These results provide new insights into the molecular breeding of crop tolerance to Cd stress.

[A clinical study of haploid hematopoietic stem cells combined with third-party umbilical cord blood transplantation in the treatment of chronic granulomatous disease].

OBJECTIVE: To investigate the clinical efficacy of haploid hematopoietic stem cells (haplo-HSC) combined with third-party umbilical cord blood (tpCB) transplantation in the treatment of X-linked chronic granulomatous disease (X-CGD). METHODS: The clinical data of 26 boys with X-CGD were retrospectively analyzed who were admitted to the Sixth Medical Center of PLA General Hospital between April 2014 and March 2018. All the patients were treated with haplo-HSC combined with tpCB transplantation. The median age of the patients was 3.5 years. The donor was the father in 25 cases and an aunt in 1 case. Transplantation was 5/6 HLA-matched in 9 cases, 4/6 in 12 cases, and 3/6 in 5 cases. The patients received busulfan, cyclophosphamide, fludarabine, or anti-thymocyte globulin for myeloablative preconditioning. Cyclosporine A and mycophenolate mofetil were used for prevention of acute graft-versus-host disease (aGVHD). Then the patients were treated with haploid bone marrow hematopoietic stem cells combined with tpCB transplantation on day 1 and haploid peripheral hematopoietic stem cells on day 2. The counts of median donor total nucleated cells, CD34+ cells, and CD3+ cells were 14.6×108/kg, 5.86×106/kg, and 2.13×108/kg respectively. RESULTS: The median time to neutrophil and platelet engraftment was 12 and 23 days after transplantation respectively. Full donor hematopoietic chimerism was observed on day 30. Twenty-five cases were from haplo-HSC and 1 was from cord blood. No primary implant failure and implant dysfunction occurred, and secondary implant failure occurred in one case. The NADPH oxidase activity returned to normal one month after transplantation. The incidence of grade I-II aGVHD and grade III-IV aGVHD was 35% and 15% respectively. Chronic GVHD (cGVHD) of the skin occurred in one case, and no progression was observed after steroid administration. During the follow-up period of 6-51 months, 25 patients survived, of whom 24 were disease-free (23 patients without cGVHD and 1 with cGVHD of the skin) and NADPH oxidase activity returned to normal; one patient developed secondary implant failure but survived; one patient died of viral interstitial pneumonia 16 months after transplantation. The 5-year event-free survival rate and overall survival rate were 81%±12% and 89%±10% respectively. CONCLUSIONS: Haplo-HSC combined with tpCB transplantation is one of the effective methods for the treatment of X-CGD in children.

The Gut Bacterial Community Composition of Wild Cervus albirostris (White-Lipped Deer) Detected by the 16S Ribosomal RNA Gene Sequencing.

Cervus albirostris (white-lipped deer) is an endemic species in China. As the name implies, C. albirostris has a characteristic pure white marking around their mouth and on the underside of the throat. The animal is a typical alpine species normally living at the height of 3500-4300 m. In this study, by pyrosequencing the 16S rRNA gene sequences, we for the first time analyzed the gut bacterial community composition in eight feces samples of wild C. albirostris. From a total of 243,634 high-quality sequences, we identified 186 genera, included in 17 prokaryotic phyla in the feces. The relative proportions of Firmicutes and Bacteroidetes were highly consistent in each individual sample. The most frequently detected genus was Ruminococcaceae UCG-005, ranging from 6.70 to 21.00%, displaying positively connections with the Rikenellaceae RC9 gut group. The bacterial communities associated with C. albirostris provide the basic knowledge for further microbiological studies and facilitates the conservation efforts of this vulnerable deer species.

[Effect of PEG-6000 Simulation Drought Stress on Physiological Characteristics of Guangfeng Medicinal Yam Plantlets].

Objective: In order to provide the theoretical basis for the Guangfeng medicinal yam( Dioscorea opposita) in field transplanting, the effect of PEG-6000 simulation drought stress on physiological characteristics of Guangfeng medicinal yam plantlets was studied. Methods: Using the method of spectrophotometer,the content of total chlorophyll,soluble total sugar, soluble protein and praline,as well as the activities of SOD,CAT and POD of Guangfeng medicinal yam plantlets were tested under PEG-6000 treatment. Results: Under PEG-6000 simulated drought stress, with the increasing of drought stress and the extension of stress time, the total chlorophyll content of Guangfeng medicinal yam plantlets continued to decline, the content of total soluble sugar, proline and MDA of Guangfeng medicinal yam plantlets significantly increased, the content of soluble protein and the activities of CAT,POD and SOD of Guangfeng medicinal yam plantlets increased at first and then decreased. Conclusion: This study reveals the changes of physiological indices of Guangfeng medicinal yam plantlets under PEG-6000 simulation drought stress, which indicated that Guangfeng medicinal yam plantlets have certain drought tolerance.

[Study on Rapid Micropropagation in Vitro Technique of Guangfeng Medicinal Yam (Dioscorea opposita) Plantlets].

OBJECTIVE: In order to provide methodology reference for virus-free and germplasm conservation of Guangfeng medicinal yam (Dioscorea opposita) plantlets, rapid micropropagation in vitro technique of Guangfeng medicinal yam plantlets was studied. METHODS: Using the method of plant tissue culture, single factor test and flow-cytometry, the basic procedure of Guangfeng medicinal yam tissue culture was established and the DNA content of Guangfeng medicinal yam plantlets and its potted seedlings was detected. RESULTS: The best disinfection procedure of stems with a bud of Guangfeng medicinal yam was washed with sterile water for three times after sterilized with 70% alcohol for 20 - 30 s and then washed with sterile water for three times again after sterilized with 0.1% mercuric chloride for 10 - 12 min; The best explants of stems with a bud of Guangfeng medicinal yam was slightly woody and more mature stems witha bud; The best proliferation culture medium of stems with a bud of Guangfeng medicinal yam was MS + 6-BA 2.0 mg/L + NAA 0.1 mg/L; The best rooting culture medium of stems with a bud of Guangfeng medicinal yam was MS + NAA 0.5 mg/L; The best culture method of Guangfeng medicinal yam plantlets was liquid culture; The best transplanting matrix of Guangfeng medicinal yam plantlets was the mixture of paddy clay and fine sand (1: 2) or the mixture of perlite and vermiculite (1: 2); The DNA content between Guangfeng medicinal yam plantlets and its potted seedlings had no significant difference. CONCLUSION: A fast and efficient micropropagation in vitro technological system of stems with a bud of Guangfeng medicinal yam is established, and the flow cytometry detect results also show the genetic stability of Guangfeng medicinal yam plantlets, whose results provide the technical and theoretical basis for the large-scale production of Guangfeng medicinal yam plantlets.

Mitochondrial-related gene expression profiles suggest an important role of PGC-1alpha in the compensatory mechanism of endemic dilated cardiomyopathy.

Keshan disease (KD) is an endemic dilated cardiomyopathy with unclear etiology. In this study, we compared mitochondrial-related gene expression profiles of peripheral blood mononuclear cells (PBMCs) derived from 16 KD patients and 16 normal controls in KD areas. Total RNA was isolated, amplified, labeled and hybridized to Agilent human 4 × 44k whole genome microarrays. Mitochondrial-related genes were screened out by the Third-Generation Human Mitochondria-Focused cDNA Microarray (hMitChip3). Quantitative real-time PCR, immunohistochemical and biochemical parameters related mitochondrial metabolism were conducted to validate our microarray results. In KD samples, 34 up-regulated genes (ratios ≥ 2.0) were detected by significance analysis of microarrays and ingenuity systems pathway analysis (IPA). The highest ranked molecular and cellular functions of the differentially regulated genes were closely related to amino acid metabolism, free radical scavenging, carbohydrate metabolism, and energy production. Using IPA, 40 significant pathways and four significant networks, involved mainly in apoptosis, mitochondrion dysfunction, and nuclear receptor signaling were identified. Based on our results, we suggest that PGC-1alpha regulated energy metabolism and anti-apoptosis might play an important role in the compensatory mechanism of KD. Our results may lead to the identification of potential diagnostic biomarkers for KD in PBMCs, and may help to understand the pathogenesis of KD.

The CBL1/9-CIPK1 calcium sensor negatively regulates drought stress by phosphorylating the PYLs ABA receptor.

The stress hormone, Abscisic acid (ABA), is crucial for plants to respond to changes in their environment. It triggers changes in cytoplasmic Ca2+ levels, which activate plant responses to external stresses. However, how Ca2+ sensing and signaling feeds back into ABA signaling is not well understood. Here we reveal a calcium sensing module that negatively regulates drought stress via modulating ABA receptor PYLs. Mutants cbl1/9 and cipk1 exhibit hypersensitivity to ABA and drought resilience. Furthermore, CIPK1 is shown to interact with and phosphorylate 7 of 14 ABA receptors at the evolutionarily conserved site corresponding to PYL4 Ser129, thereby suppressing their activities and promoting PP2C activities under normal conditions. Under drought stress, ABA impedes PYLs phosphorylation by CIPK1 to respond to ABA signaling and survive in unfavorable environment. These findings provide insights into a previously unknown negative regulatory mechanism of the ABA signaling pathway, which is mediated by CBL1/9-CIPK1-PYLs, resulting in plants that are more sensitive to drought stress. This discovery expands our knowledge about the interplay between Ca2+ signaling and ABA signaling.

Calcium-dependent protein kinases CPK21 and CPK23 phosphorylate and activate the iron-regulated transporter IRT1 to regulate iron deficiency in Arabidopsis.

Iron (Fe) is an essential micronutrient for all organisms. Fe availability in the soil is usually much lower than that required for plant growth, and Fe deficiencies seriously restrict crop growth and yield. Calcium (Ca2+) is a second messenger in all eukaryotes; however, it remains largely unknown how Ca2+ regulates Fe deficiency. In this study, mutations in CPK21 and CPK23, which are two highly homologous calcium-dependent protein kinases, conferredimpaired growth and rootdevelopment under Fe-deficient conditions, whereas constitutively active CPK21 and CPK23 enhanced plant tolerance to Fe-deficient conditions. Furthermore, we found that CPK21 and CPK23 interacted with and phosphorylated the Fe transporter IRON-REGULATED TRANSPORTER1 (IRT1) at the Ser149 residue. Biochemical analyses and complementation of Fe transport in yeast and plants indicated that IRT1 Ser149 is critical for IRT1 transport activity. Taken together, these findings suggest that the CPK21/23-IRT1 signaling pathway is critical for Fe homeostasis in plants and provides targets for improving Fe-deficient environments and breeding crops resistant to Fe-deficient conditions.

Quality appraisal of clinical practice guidelines for motor neuron diseases or related disorders using the AGREE II instrument.

Objectives: This study aimed to systematically assess the quality of CPGs for motor neuron diseases (MNDs) or related disorders and identify the gaps that limit evidence-based practice. Methods: Four scientific databases and six guideline repositories were searched for eligible CPGs. Three researchers assessed the eligible CPGs using the Appraisal of Guidelines Research and Evaluation II instrument. The distribution of the level of evidence and strength of recommendation of these CPGs were determined. The univariate regression analysis was used to explore the characteristic factors affecting the quality of CPGs. Results: Fifteen CPGs met the eligibility criteria: 10 were for MND and 5 were for spinal muscular atrophy. The mean overall rating score was 44.5%, and only 3 of 15 CPGs were of high quality. The domains that achieved low mean scores were applicability (24.4%), rigor of development (39.9%), and stakeholder involvement (40.3%). Most recommendations were based on low-quality evidence and had a weak strength. The CPGs that were updated, meant for adults, and evidence based, and used a CPG quality tool and a grading system were associated with higher scores in certain specific domains and overall rating. Conclusion: The overall quality of CPGs for MNDs or related disorders was poor and recommendations were largely based on low-quality evidence. Many areas still need improvement to develop high-quality CPGs, and the use of CPG quality tools should be emphasized. A great deal of research on MNDs or related disorders is still needed to fill the large evidence gap.

Effectiveness of human mesenchymal stem cells derived from bone marrow cryopreserved for 23-25 years.

OBJECTIVE: To evaluate long-term cryopreserved human bone marrow cells (BMCs) as a source of functional mesenchymal stem cells (MSCs). METHODS: Samples of human BMCs that were cryopreserved for 23-25 years (n=20) were thawed to obtain an initial culture and a primary culture (P(0)) that was propagated through five passages (P(1)-P(5)) to obtain MSCs. Freshly collected human bone marrow samples (n=20) were used as controls for comparison of efficiency of recovery and growth characteristics of MSCs. P(3) cultures were tested for their capacity to differentiate into osteoblasts, adipocytes, and neuronal cells. Appropriate staining, immunohistochemical and biochemical methods were employed to ascertain cell type identities at different stages of culturing. RESULTS: In the initial culture, the cell adherence rate of the cryopreserved cells was significantly lower than that of controls (19.7% vs. 38.2%, p<0.05) while the relative rate of recovery of MSCs was only 48.5±8.6% in P(0). At the end of P(3), fibroblast-like cells accounted for about 95% of cells in both cryopreserved and control groups (p>0.05). These cells were positive for essential MSC surface molecules (CD90, CD105, CD166, CD44, CD29, CD71, CD73) and negative for haematopoietic and endothelial cell markers (CD45, CD34, HLA-DR). The cell growth and cell cycle patterns were similar for both groups. MSCs at P(3) from both groups had similar capacities to differentiate in vitro into osteoblasts, adipocytes, and neuronal cells. CONCLUSION: Using the methods described here, long-term (23-25 years) cryopreserved human BMCs can be successfully cultivated to obtain MSCs that have good differentiation capabilities.

[Susceptibility to prostate cancer in Han Chinese: single nucleotide polymorphism analysis of 1 667 cases].

OBJECTIVE: Prostate cancer (PCa) has the highest incidence among male malignancies in Western industrialized countries and, as a most common malignant disease in urology, its incidence has been increasing in recent years in Chinese men. This study was to investigate the risk loci associated with PCa susceptibility in Han Chinese by analyzing single nucleotide polymorphisms (SNP). METHODS: We collected peripheral blood samples from 1 667 PCa patients and 1 525 healthy men, and detected 40 loci associated with PCa susceptibility by analyzing SNPs using Sequenom technology. RESULTS: Of the 40 known loci, 16 were confirmed to be significantly associated with PCa susceptibility (P < 0.05). The loci 1, 2 and 5 at 8q24, 10q11 and 22q13.2 also contributed to PCa susceptibility in different ethnic groups. CONCLUSION: PCa susceptibility is obviously associated with the risk loci rs1465618, rs721048, rs12621278, rs7679673, rs12653946, rs339331, rs1512268, rs10086908, rs16901979, rs1447295, rs10993994, rs10896449, rs902774, rs9600079, rs11649743 and rs5759167 in Chinese Han population.

[Effect of yifei huoxue granule on the proliferation and the TGF-beta activity of rat pulmonary artery smooth muscle cells induced by platelet-derived growth factor BB].

OBJECTIVE: To explore the effects of Yifei Huoxue Granule (YFHXG) on the proliferation and the transforming growth factor-beta (TGF-beta) activity of rat pulmonary artery smooth muscle cells (PASMCs) induced by platelet-derived growth factor BB (PDGF-BB). METHODS: Using tissue block adhering wall method, the primary rat PASMCs were cultured. PASMCs at the log phase growth were randomly divided into the control group, the PDGF-BB group, the PDGF-BB + high YFHXG group (at the final concentration of 7.5 mg/mL), the PDGF-BB + middle YFHXG group (at the final concentration of 1.5 mg/mL), and the PDGF-BB + low YFHXG group (at the final concentration of 0.3 mg/mL), respectively. MTT assay were employed to determine the cell proliferation rate of each group. Flow cytometric analyses were used to detect the cell cycle constituent ratio and the proliferation index (PI). In addition, TGF-beta protein's expression was determined by immunocytochemical assay (SP method). RESULTS: Compared with the control group, the proliferation of PASMCs in the PDGF-BB group was obviously active (P<0.01). But when compared with the PDGF-BB group, along with the increased concentration of YFHXG, the growth of PASMCs was obviously inhibited, the cell ratio of G0/G1, phase obviously increased, the cell ratio of S + G2/M phase significantly decreased, and PI significantly decreased. Besides, the expression of TGF-beta protein decreased in a dose-dependent manner (P<0.05, P<0.01). CONCLUSIONS: PDGF-BB could directly stimulate the proliferation of PASMCs. YFHXG had a significant inhibition on the proliferation of rat PASMCs induced by PDGF-BB and could regulate the expression of TGF-beta.

[Quantitative analysis and classification of tongue inspection based on the visible reflection spectrum].

OBJECTIVE: In this study, optical data on color of tongue tips were collected by using a visible reflection spectrum system. Quantitative method of tongue inspection and classification of tongue states including pale, pale red, red and crimson manifestations were investigated. METHODS: Chromaticity coordinates of the tongue tips from 98 subjects were calculated on the basis of the visible reflection spectrum. The tongue color was quantified and classified by the visible reflection spectrum in the range from 590 nm to 780 nm, based on the higher red-band energy distribution on the tongue tip color. RESULTS: It was found that comparison and analysis of tongue tip color from different samples would be well-suited after spectrum vector normalization, and the difference of tongue tip color between different samples could be observed easily when the tongue tip optical data were sited in CIE 1931 chromaticity diagram. The tongue tip colors were analyzed quantitatively and classified by the spectral energy intensity at the wavelength of 670 nm and (or) spectral energy ratio of red bank from 590 nm to 780 nm. The results of classification showed that there was sound corresponding accuracy with the clinical diagnosis of pale tongue, pale red tongue, red tongue and crimson tongue. CONCLUSION: In this study, based on the collection of the information data on tongue tip characteristics with the visible spectrum from 380 nm to 780 nm, the quantitative analysis of tongue inspection for pale tongue, pale red tongue, red tongue and crimson tongue was established. The quantitative value for tongue tip color is an effective method for classification of the condition of the tongue tip, which provides a useful tool for the modernization of tongue inspection in traditional Chinese medicine.

[Observation on conditions and related factors of Keshan disease in Shandong province, 1990-2007].

OBJECTIVE: To observe the serial changes of condition and related factors of Keshan disease (KSD) and provide the scientific basis for disease control and further research. METHODS: The villages in KSD epidemic area of Juxian, Yishui, Pingyi, Zoucheng counties were selected. Since 1990, every five-year was counted as a stage. For the first to third stage, 3-14 year-old residents and over 14 year-old suspicious patients were selected as surveillance subjects. And in the fourth stage, all residents were selected as surveillance subjects. The same group of surveillance subjects in each stage were observed consecutively for 5 years. Surveillance contents included physical checkup, electrocardiogram (ECG) and Xray. At the same time, the selenium (Se) concentration in hair, wheat, corn and sweet potato was measured. The economic income and grain availability were also investigated. RESULTS: Totally, 14,510 cases were visited during 18 years. The incidence of KSD was 3.02% in the first stage, 2.31% in the second stage, 3.57% in the third stages and 3.65% in the fourth stage. Totally, 14,510 cases were examined by ECG, 809 cases showed the abnormal ECG and the total incidence of abnormal ECG was 5.49%. The incidence of abnormal ECG was 3.52% -5.24% from 1990 to 2004 but was 10.97%-10.91% from 2005 to 2007. 732 of hair samples, 701 of wheat samples, 615 of corn samples and 643 of sweet potato samples were collected and the Se concentration was determined by the fluorescent method. Se levels in hair samples had increased (P < 0.05) year by year but Se levels in food have not changed significantly. The economic income and grain availability had increased gradually from 535.8 yuan and 254.6 kg per person in 1990 to 2968.0 yuan and 602.0 kg per person in 2007. CONCLUSION: The condition of KSD was in a stable situation in Shandong Province. Related factors improvement should be an important environmental condition.

[Change in coagulation after open abdominal wound subjected to seawater immersion].

OBJECTIVE: To explore the effects of hyperosmotic fluid and low temperature on hemorrhage and coagulation system after immersion of dogs with open abdominal wounds in seawater. METHODS: Twenty healthy dogs were subjected to open abdominal injury, then dogs were randomized equally into two groups: the control group (n=10) (without seawater immersion) and seawater immersion group (n=10). The variables of prothrombin time (PT), partial thromboplastin time (APTT), D-dimer and factor II, granule membrane protein-140 (GMP-140), endothelin-1 (ET-1) were determined. RESULTS: PT and APTT were significantly prolonged. D-dimer, GMP-140, and ET-1 were increased, while factor II was decreased after the dog with open abdominal wound was immersed in seawater (all P<0.05). Compared with the variables of control group, PT, APTT, D-dimer and factor II, ET-1 in seawater immersion group had markedly changed (all P<0.05) except GMP-140 at different time points (all P>0.05). CONCLUSION: Obvious vascular endothelial cell dysfunction, platelet activation, inhibition of coagulation factor activity, coagulopathy, and disorders in thrombosis and fibrinolysis system activation occur after dogs with open abdominal wounds are immersed in seawater.

[Unrelated umbilical cord blood transplantation as a treatment for children with malignant leukemia].

OBJECTIVE: Unrelated umbilical cord blood has the clear benefits of rapid availability and a reduced stringency of requirement for HLA match. The aim of this study was to investigate the efficacy of unrelated umbilical cord blood transplantation (UCBT) in the treatment of malignant leukemia in children. METHODS: Six children with malignant leukemia, including three cases of acute lymphocyte leukemia [two high-risk patients and one standard-risk patient in complete remission (CR)], two juvenile myelomonocytic leukemia (one in CR and one in the accelerating stage), and one acute myeloblastic leukaemia (in CR), received a UCBT. The umbilical cord blood grafts were HLA-matched (n=1) or HLA-mismatched at 1 (n=1) or 2 (n=1) or 3 (n=3) loci. Busulfan/cyclophosphamide/antithymocyte globulin (ATG) or total body irradiation (TBI)/cyclophosphamide/ATG was involved in the myeloablative pretreatment regimen. The median infused donor nucleated cell was 8.51 x 10(7)/kg of recipient weight, and the CD34+ cell was 1.81 x 10(5)/kg of recipient weight. Cyclosporin, corticoid, mycophenolate mofetil and daclizumab were used for prophylaxis of acute graft versus host disease (GVHD). RESULTS: The time to reach an absolute neutrophil count of 0.5 x 10(9)/L ranged from 11 to 35 days (median: 13 days) and the time to reach a platelet count of 20 x 10(9)/L ranged from 27 to 68 days (median: 30 days) after transplantation, and the donors' hematopoietic stem cells were shown in these patients. Four patients developed grade I to III acute GVHD but responded to steroids and daclizumab. Chronic GVHD was not found during a 3-16-month follow-up. Four patients survived and did not relapse during the follow-up. CONCLUSIONS: Unrelated umbilical cord blood is an alternative source of hematopoietic stem cells for patients with leukemia. UCBT can tolerate 1-2 HLA mismatches. The incidence of acute GVHD is high in UCBT recipients.

[Applications of the hospital statistics management system].

The Hospital Statistics Management System is built on an Office Automation Platform of Shandong provincial hospital system. Its workflow, role and popedom technologies are used to standardize and optimize the management program of statistics in the total quality control of hospital statistics. The system's applications have combined the office automation platform with the statistics management in a hospital and this provides a practical example of a modern hospital statistics management model.

Overexpression of zeaxanthin epoxidase gene from Medicago sativa enhances the tolerance to low light in transgenic tobacco.

Zeaxanthin epoxidase (ZEP) plays an important role in xanthophyll cycle which is a process closely related to photosynthesis. However, an impact of ZEP on low-light stress has not been studied. In this study, the functions of an alfalfa (Medicago sativa) zeaxanthin epoxidase gene, MsZEP, in response to low-light stress were investigated by heterologous expression in tobacco (Nicotiana tabacum). Under normal light conditions, the measured parameters were not significantly different between transgenic and wild-type (WT) plants except for non-photochemical quenching value and chlorophyll a content. However, the differences were detected under low-light stress. We found that MsZEP-overexpression tobacco grew faster than WT (p≤0.05). The leaf fresh weight and leaf area of transgenic plants were significantly higher, and the number of stomata was greater in MsZEP-overexpression tobacco. As for photosynthetic characteristics, quantum yield of PSII (ΦPSII) and maximal photochemical efficiency of PSII (Fv/Fm) were not significantly different, whereas non-photochemical quenching (NPQ), net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of MsZEP-overexpression tobacco were significantly higher than in WT plants. However, no significant difference was detected between the two types of tobacco in chlorophyll and carotenoids content. In conclusion, MsZEP can improve the ability of tobacco to withstand low-light stress, which might be due to its stronger photosynthetic activity and the improvement of stomatal density under low light.

Metagenomic analysis of Sichuan takin fecal sample viromes reveals novel enterovirus and astrovirus.

The Sichuan takin inhabits the bamboo forests in the Eastern Himalayas and is considered as a national treasure of China with the highest legal protection and conservation status considered as vulnerable according to The IUCN Red List of Threatened Species. In this study, fecal samples of 71 Sichuan takins were pooled and deep sequenced. Among the 103,553 viral sequences, 21,961 were assigned to mammalian viruses. De novo assembly revealed genomes of an enterovirus and an astrovirus and contigs of circoviruses and genogroup I picobirnaviruses. Complete genome sequencing and phylogenetic analysis showed that Sichuan takin enterovirus is a novel serotype/genotype of the species Enterovirus G, with evidence of recombination. Sichuan takin astrovirus is a new subtype of bovine astrovirus, probably belonging to a new genogroup in the genus Mamastrovirus. Further studies will reveal whether these viruses can also be found in Mishmi takin and Shaanxi takin and their pathogenic potentials.

[Measures for Maintaining the Vitality of Peripheral Blood Hematopoietic Stem Cells in vitro].

OBJECTIVE: To explore the maintaining measures for the vitality of hematopoietic stem cells (HSC) in vitro, so as provide technical support for ultra long distance transport of HSC collected from unrelated donors. METHODS: Peripheral blood hematopoietic stem cells (PBHSC) were treated by different methods according to various groups, then stored at 4 ℃ in the refrigerator. The percentage of CD34+ cells, relative cell activity, relative cell proliferation rate, relative colony-forming rate, oxygen fraction and intracellular reactive oxygen species (ROS) were detected at 0, 24, 48 and 72 h after storage of PBHSC respectively. RESULTS: The percentage of CD34+ cells during 72 h storage did not altered. Along with the prolonging of storage time, the relative cell activity, relative cell proliferation rate and relative colony-forming rate gradually decreased in untreated PBHSC(control group), the related coefficients were -0.796, -0.883 and -0.815 respectively. Plasma dilution, antioxidants and oxygenation could improve the relative cell activity and relative cell proliferation rate, but oxygenation could decrease the relative colony-forming rate of PBHSC. The combination of 2 or 3 factors showed stronger protection effects on PBHSC. The intracellular level of ROS decreased gradually with the prolonging of storage time. Oxygenation of PBHSC could increase oxygen fraction, and also increase the intracellular level of ROS at the same time. The addition of antioxidants could reduce the level of ROS. CONCLUSION: The percentage of CD34+ cells can not serve as the indicator of PBHSC vitality. Plasma dilution, oxygenation and antioxidants can increase the survival and viability of PBHSC, but oxygenation can increase the intracellular ROS level and impair colony-forming ability of PBHSC. The combination of multiple factors can maintain the vitality of PBHSC better.