Effects of different short-term tillage managements on rhizosphere soil autotrophic CO2 -fixing bacteria in a double-cropping rice paddy field.

Soil autotrophic bacteria community plays an important role in carbon (C) cycling process in soil, but there is still limited information about how the rhizosphere soil microbe that drives this process respond to combined application of tillage with crop residue incorporation managements under a double-cropping rice (Oryza sativa L.) paddy field in southern China. Therefore, the 6-years short-term tillage treatment on rhizosphere soil autotrophic bacteria community [RubisCO gene (cbbL)] under the double-cropping rice paddy field in southern China was studied using the high-throughput sequencing method in the present article. The field experiment included four tillage treatments: conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), no-tillage with crop residue retention (NT) and rotary tillage with all crop residues removed as a control (RTO). The results showed that abundance, composition and activity of rhizosphere soil cbbL-carrying bacteria were obviously influenced by application of different tillage treatments. The rhizosphere soil abundant cbbL and 16S rRNA genes as well as RubisCO activity with CT, RT and NT treatments were higher than that of RTO treatment. The cbbL sequences in rhizosphere soil with CT, RT and NT treatments mainly included Azoarcus_sp._KH33C, Ralstonia_pickettii, Thermomonospora_curvata, Variovorax_paradoxus and uncultured_proteobacterium. Meanwhile, the results indicated that cbbL-carrying bacterial composition was significantly affected by soil organic carbon, microbial biomass carbon, dissolved organic carbon contents and soil bulk density. There had an obvious difference in characteristics of rhizosphere soil autotrophic bacteria community between CT, RT, NT treatments and RTO treatment. Therefore, it was a beneficial practice for improving rhizosphere soil autotrophic bacteria community in the double-cropping rice paddy field in southern China by combined application of tillage with crop residue incorporation practices.

Effects of short-term soil tillage practice on activity and community structure of ammonia-oxidizing bacteria and archaea under the double-cropping rice field.

AIMS: The potential nitrification activity (PNA), population size and community composition of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in paddy soil from a short-term (5 years) tillage field experiment conducted at tillering stage of late rice were investigated using the shaken slurry method and quantitative real-time polymerase chain reaction. METHODS AND RESULTS: The experiment included four tillage treatments: conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), no-tillage with crop residue returning (NT) and rotary tillage with all crop residues removed as a control (RTO). The results showed that PNA in paddy soil of CT, RT and NT treatments was higher than that of RTO treatment, and the abundance of AOA and AOB was much higher in paddy soil of CT, RT and NT treatments than RTO treatment. Meanwhile, PNA and the abundance of AOB and AOA in paddy soil were greatly enhanced by combined application of tillage and crop residue, whereas PNA and the abundance of AOB and AOA in paddy soil were decreased by combined application of no-tillage and crop residue. Moreover, PNA was closely correlated with the abundance and community structure of AOB rather than AOA. The results also showed that PNA and the population sizes of AOB and AOA in crop incorporation treatments were higher than that of crop residue removed treatment. Cluster and redundancy analyses indicated that crop residue effect played a more important role in shaping AOA community structure compared to short-term tillage management. CONCLUSIONS: The results indicated that AOB rather than AOA functionally dominated ammonia oxidation in the double-cropping rice paddy soil, the activities of AOB and AOA were increased and the community structure was also changed under the combination of conventional tillage, rotary tillage and crop residue condition. SIGNIFICANCE AND IMPACT OF STUDY: The activity and community structure of AOB and AOA, which were affected by the combination of tillage and crop residue managements, play an important role in cycling of nitrogen.

Broad-spectrum virucidal activity of bacterial secreted lipases against flaviviruses, SARS-CoV-2 and other enveloped viruses

Viruses are the major aetiological agents of acute and chronic severe human diseases that place a tremendous burden on global public health and economy; however, for most viruses, effective prophylactics and therapeutics are lacking, in particular, broad-spectrum antiviral agents. Herein, we identified 2 secreted bacterial lipases from a Chromobacterium bacterium, named Chromobacterium antiviral effector-1 (CbAE-1) and CbAE-2, with a broad-spectrum virucidal activity against dengue virus (DENV), Zika virus (ZIKV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The CbAEs potently blocked viral infection in the extracellular milieu through their lipase activity. Mechanistic studies showed that this lipase activity directly disrupted the viral envelope structure, thus inactivating infectivity. A mutation of CbAE-1 in its lipase motif fully abrogated the virucidal ability. Furthermore, CbAE-2 presented low toxicity in vivo and in vitro, highlighting its potential as a broad-spectrum antiviral drug.

Microbial carbon source utilization in rice rhizosphere and nonrhizosphere soils with short-term manure N input rate in paddy field.

Carbon (C) plays a vital role in regulating soil nutrient cycling and increasing soil microbial community, but there is still limited information on how C source utilization characteristics responds to soil physical and chemical properties changes under double-cropping rice (Oryza sativa L.) paddy field in southern China. Therefore, the effects of different short-term manure nitrogen (N) input rate managements on C source utilization characteristics in rice rhizosphere and non-rhizosphere soils under double-cropping rice field in southern China were studied by using 18O-H2O method. Therefore, a field experiment were established in Ningxiang city of Hunan Province, and five different fertilizer treatments were applied: (1) 100% N of chemical fertilizer (M0), (2) 30% N of organic manure and 70% N of chemical fertilizer (M30), (3) 50% N of organic manure and 50% N of chemical fertilizer (M50), (4) 100% N of organic manure (M100), and (5) without N fertilizer input as control (CK). The results showed that soil microbial biomass C content, soil microbial growth rate, and soil microbial basal respiration with application of organic manure treatments (M30, M50, M100) were significantly higher (p < 0.05) than that of CK treatment. And the soil C utilization efficiency with M0 treatment were significantly higher (p < 0.05) than that of M100 treatment. Compared with CK and M0 treatments, the metabolic capacity of soil microorganisms to exogenous C sources with M30, M50 and M100 treatments were increased. The largest types of exogenous C source was carboxylic acids, followed by amino acid and carbohydrate, and complex compounds was the smallest. The RDA analysis results indicated that fertilizer treatments significantly changed the utilization characteristics of soil microorganisms to exogenous C sources. As a result, this study found that characteristics of soil C source utilization were significantly affected by different short-term manure N input rate managements.

Clinical Application of the Expression of LOXL2 mRNA and Tenascin-C mRNA in Tissues of the Bile Duct Cancer / 现代检验医学杂志

Objective To explore the clinical application of the expression of LOXL2 mRNA and Tenascin-C mRNA in tissues for the disease with the bile duct cancer.Methods The serum and clinical data in 35 cases of patients with the bile duct cancer (cancer group) and 28 cases of patients with normal bile duct tissue (control group) were collected,used the real-time fluorescent quantitative PCR (real-time-PCR,RT-PCR) technology to detect the expression of LOXL2 mRNA and TenascinC mRNA in tissues toobserve the relationship between the changes and the bile duct cancer for the two markers.Results The expression of LOXL2 mRNA and Tenascin-C mRNA in tissues in the cancer group were 1.27±0.18 and 1.39±0.19,which of ones in the control group were 0.20±0.06 and 0.23±0.06.In the cancer group,the expression of LOXL2 mRNA and Tenascin-C mRNA in tissues respectively with comparision to those in the control group were significantly higher,the differences had statistical significance(t=52.18,56.87,P＜0.01),which of ones in the cancer group was positively related (r=0.687,P＜0.01).Conclution The expression of LOXL2 mRNA and Tenascin-C mRNA in tissues may be a molecular targets for the disease with the bile duct cancer in the early diagnosis and judgment of progression in the courses of this disease.

Clinical Research of Detecting Plasma MiRNA-21 and MiRNA-143 for Identifying Early Esophageal Cancer and Benign Esophageal Diseases / 现代检验医学杂志

Objective To explore the clinical significance of detection of plasma microRNA-21,-143 in identifying early esophageal cancer and esophageal non-tumor diseases.Methods The expression of plasma microRNA-21,-143 in 27 cases of patients with early esophageal cancer (esophagus cancer group),25 cases of patients with non-esophageal tumor (non-esophageal tumor group)and in the healthy controls were detected by RT-PCR,and detected the levels of plasma CEA and CA72-4 by the electrochemical luminescence technology,which of changes were analysed to observe the relationship between the changes and the esophageal cancer,the benign esophageal diseases for the two markers.Results The expression of plasma microRNA-21,-143 in the esophagus cancer group were 0.93±0.17,0.27±0.05,which of ones in the non-esophagus cancer group were 0.25±0.03,0.99±0.15,and with those in the control group were 0.23±0.03,1.02±0.15.Compared with those in the non-esophagus cancer group,the expression of plasma microRNA-21,-143 were obviously up or down-regulated with significant differences (t=10.87,11.55,P＜0.01).Compared with those in the control group,which of ones were obviously up or down-regulated with significant differences (t=9.20,9.07,P＜0.01),and with no statistical significances in comparison between the esophagus cancer group and the control group (t=1.39,1.19,P＞0.05).The positiverate of plasma microRNA-21,-143 in the esophageal cancer,non-esophagus cancer group and the control group were,81.4 ％ (22/27),4.0 ％(1/25) and 0 (0/24);85.1％ (23/27),4.0％ (1/25),and 0 (0/24),respectively.The positive rate of microRNA-21,-143 in the esophageal group respectively in comparison with those in the non-esophagus cancer group and the control group were significantly higher,the differences had statistical significances (x2 =31.59,34.39,P＜ 0.01;x2 =34.42,37.23,P＜ 0.01).The expression of two markers in the esophagus cancer group were no statistically significant differences compared with control group (x2 =0.980,0.980,P＞0.05).The sensitivity and specificity of microRNA-21,-143 in early diagnosis on the esophageal cancer were 81.4 ％,97.9 ％ and 85.1％,97.9 ％.The sensitivity of microRNA-21,-143 in the esophageal group were significantly higher compared with those of CEA and CA72-4,the differences were statistically significant (x2 =12.79,P＜0.01;x2 =5.33,P＜0.05;x2 =15.03,P＜0.01;x2 =6.95,P＜0.05).The specificity of microRNA-21,-143 in the esophageal cancer group were no statistically significant differences in comparison with those of CEA and CA72-4 (x2 =1.043,0.000,P＞0.05) and (x2=1.043,0.000,P＞0.05),respectively.The analysis results from the spearman correlation test showed that in the esophageal cancer group,the expression of plasma microRNA-21,-143 had a negative correlation (r =0.658,P＜0.01).Which of ones respectively associated with the levels of CEA and CA72-4 (r=0.607,0.623,P＜0.01 and r=0.579,0.610,P＜0.01).Conclution The detection of expression of plasma miRNA-21,miRNA-143 in the patients with the early esophageal cancer and non-esophageal tumor can provide a new train of thought for pathologic diagnosis of early esophageal cancer.