Non-targeted effects of nitrification inhibitors on soil free-living nitrogen fixation modified with weed management.

Biological nitrogen fixation and nitrification inhibitor applications contribute to improving soil nitrogen (N) availability, however, free-living N fixation affected by nitrification inhibitors has not been effectively evaluated in soils under different weed management methods. In this study, the effects of the nitrification inhibitors dicyandiamide (DCD) and 3, 4-dimethylpyrazole phosphate (DMPP) on the nitrogenase, nifH gene，and diazotrophic communities in soils under different weed management methods (AMB, weeds growth without mowing or glyphosate spraying; GS, glyphosate spraying; MSG, mowing and removing weeds and glyphosate spraying; and WM, mowing aboveground weeds) were investigated. Compared to the control counterparts, the DCD application decreased soil nitrogenase activity and nifH gene abundance by 4.5 % and 37.9 %, respectively, under the GS management method, and the DMPP application reduced soil nitrogenase activity by 20.4 % and reduced the nifH gene abundance by 83.4 % under the MSG management method. The application of nitrification inhibitors significantly elevated soil NH4+-N contents but decreased NO3--N contents, which had adverse impacts on soil nifH gene abundance and nitrogenase activity. The nifH gene abundances were also negatively impacted by dissolved organic N and Geobacter but were positively affected by available phosphorus and diazotrophic community structures. Nitrification inhibitors significantly inhibited Methylocella but stimulated Rhizobiales and affected soil diazotrophic communities. The nitrification inhibitors DCD and DMPP significantly altered soil diazotrophic community structures, but weed management outweighed nitrification inhibitors in reshaping soil diazotrophic community structures. The non-targeted effects of the nitrification inhibitors DMPP and DCD on soil free-living N fixation were substantially influenced by the weed management methods.

An Electrochemical Sensor Based on a Porous Biochar/Cuprous Oxide (BC/Cu2O) Composite for the Determination of Hg(II).

Mercuric ion (Hg2+) in aqueous media is extremely toxic to the environment and organisms. Therefore, the ultra-trace electrochemical determination of Hg2+ in the environment is of critical importance. In this work, a new electrochemical Hg2+ sensing platform based on porous activated carbon (BC/Cu2O) modified with cuprous oxide was developed using a simple impregnation pyrolysis method. Differential pulse anodic stripping voltammetry (DPASV) was used to investigate the sensing capability of the BC/Cu2O electrode towards Hg2+. Due to the excellent conductivity and large specific surface area of BC, and the excellent catalytic activity of Cu2O nanoparticles, the prepared BC/Cu2O electrode exhibited excellent electrochemical activity. The high sensitivity of the proposed system resulted in a low detection limit of 0.3 ng·L-1 and a wide linear response in the ranges from 1.0 ng·L-1 to 1.0 mg·L-1. In addition, this sensor was found to have good accuracy, acceptable precision, and reproducibility. All of these results show that the BC/Cu2O composite is a promising material for Hg2+ electrochemical detection.

Genome-wide identification of the WRKY gene family in Camellia oleifera and expression analysis under phosphorus deficiency.

Camellia oleifera Abel. is an economically important woody edible-oil species that is mainly cultivated in hilly areas of South China. The phosphorus (P) deficiency in the acidic soils poses severe challenges for the growth and productivity of C. oleifera. WRKY transcription factors (TFs) have been proven to play important roles in biological processes and plant responses to various biotic/abiotic stresses, including P deficiency tolerance. In this study, 89 WRKY proteins with conserved domain were identified from the C. oleifera diploid genome and divided into three groups, with group II further classified into five subgroups based on the phylogenetic relationships. WRKY variants and mutations were detected in the gene structure and conserved motifs of CoWRKYs. Segmental duplication events were considered as the primary driver in the expanding process of WRKY gene family in C. oleifera. Based on transcriptomic analysis of two C. oleifera varieties characterized with different P deficiency tolerances, 32 CoWRKY genes exhibited divergent expression patterns in response to P deficiency stress. qRT-PCR analysis demonstrated that CoWRKY11, -14, -20, -29 and -56 had higher positive impact on P-efficient CL40 variety compared with P-inefficient CL3 variety. Similar expression trends of these CoWRKY genes were further observed under P deficiency with longer treatment period of 120d. The result indicated the expression sensitivity of CoWRKYs on the P-efficient variety and the C. oleifera cultivar specificity on the P deficiency tolerance. Tissue expression difference showed CoWRKYs may play a crucial role in the transportation and recycling P in leaves by affecting diverse metabolic pathways. The available evidences in the study conclusively shed light on the evolution of the CoWRKY genes in C. oleifera genome and provided a valuable resource for further investigation of functional characterization of WRKY genes involved to enhance the P deficiency tolerance in C. oleifera.

Foliar Fertilizer Application Alters the Effect of Girdling on the Nutrient Contents and Yield of Camellia oleifera.

Improving the economic benefits of Camellia oleifera is a major problem for C. oleifera growers, and girdling and foliar fertilizer have significant effects on improving the economic benefits of plants. This study explains the effects of girdling, girdling + foliar fertilizer on nutrient distribution, and the economic benefits of C. oleifera at different times. It also explains the N, P, and K contents of roots, leaves, fruits, and flower buds (sampled in March, May, August, and October 2021) and their economic benefits. The results showed girdling promoted the accumulation of N and K in leaves in March 2021 (before spring shoot emergence) but inhibited the accumulation of P, which led to the accumulation of P in roots and that of N in fruits in August 2021 (fruit expansion period). Foliar fertilizer application after girdling replenished the P content of leaves in March 2021, and P continued to accumulate in large quantities at the subsequent sampling time points. The N and P contents of the root system decreased in March. In October (fruit ripening stage), girdled shrubs showed higher contents of N and K in fruits and flower buds, and consequently lower relative contents of N and K in roots and leaves but higher content of P in leaves. Foliar fertilizer application slowed down the effects of girdling on nutrient accumulation in fruits and flower buds. Spraying foliar fertilizer decreased the N:P ratio in the flower buds and fruits of girdled plants. Thus, foliar fertilizer spray weakened the effects of girdling on the nutrient content and economic benefits of C. oleifera. In conclusion, girdling changed the nutrient accumulation pattern in various organs of C. oleifera at different stages, increased leaf N:K ratio before shoot emergence, reduced root K content at the fruit expansion stage and the N:K ratio of mature fruit, and promoted economic benefits.

The effects of biochar derived from feedstock with different Si and Al concentration on soil N2O and CO2 emissions.

Desilicification and allitization is important characteristic of acidic soil. While decrease in soil silicon (Si) may generate Si limitation, the increase of aluminum (Al) will aggravate soil acidification. Biochar has been used in acid soil improvement, which could mitigate nitrous oxide (N2O) emissions and alter soil Si and Al concentration. However, the effect of biochar with different Si and Al concentration on greenhouse gas emissions remains unclear. We evaluated the effects of biochar derived from feedstock with different Si (moso bamboo leaves, BL; rice straw, RS) and Al (Camellia oleifera fruit shell, CFS; C. oleifera leaves, CL) concentration on greenhouse gas emissions and soil acidification. Microbial functional gene abundance associated with N2O emissions were measured to further explore the response of microbiological community. The results showed that BL, RS, CFS and CL significantly increased soil pH (by 19.2%, 16.7%, 18.7% and 24.9%, respectively), decreased soil exchangeable acid and exchangeable Al content, and reduced N2O emission rate of soil with nitrogen (N) (by 14.2%, 27.3%, 25.6% and 38.7%, respectively), which correlated with increase in soil nosZ abundance. BL, RS, CFS and CL increased soil nirK (by 325.6%, 66.7%, 155.8%, and 253.2%, respectively) and nosZ (by 198.6%, 174.1%, 72.2%, and 152.0%, respectively) abundance with N. Structural equation model showed that Si input via biochar application directly reduced N2O emissions, and soil acid-extractable Si is inversely proportional to N2O emission rate. In addition, Si input reduced carbon dioxide (CO2) emissions via indirect effects. Al input via biochar addition indirectly affected N2O and CO2 emissions through mainly indirect effects on other soil factors. In intensive management and production activities, Si-rich biochar can be considered instead of sole addition as fertilizer, which will be beneficial to the sustainable development of agricultural and forestry production in acid soil areas, and mitigation of global change.

Facile Synthesis of Nitrogen Self-Doped Porous Carbon Derived from Cicada Shell via KOH Activation for Simultaneous Detection and Removal of Cu2.

Sensitive detection and efficient removal of heavy metal ions with high toxicity and mobility are of great importance for environmental monitoring and control. Although several kinds of functional materials have been reported for this purpose, their preparation processes are complicated. Herein, nitrogen self-doped activated porous biochar (NAC) was synthesized in a facile process via an activation-carbonization strategy from cicada shell rich in chitin, and subsequently employed as an effective functional material for the simultaneous determination and removal of Cu2+ from aqueous media. With its unique porous structure and abundant oxygen-containing functional groups, along with the presence of heteroatoms, NAC exhibits high sensitivity for the electrochemical sensing of Cu2+ in concentrations ranging from 0.001 to 1000 µg·L-1, with a low detection limit of 0.3 ng·L-1. Additionally, NAC presents an excellent removal efficiency of over 78%. The maximum adsorption capacity is estimated at 110.4 mg/g. These excellent performances demonstrate that NAC could serve as an efficient platform for the detection and removal of Cu2+ in real environmental areas.

Bismuth Nanoclusters/Porous Carbon Composite: A Facile Ratiometric Electrochemical Sensing Platform for Pb2+ Detection with High Sensitivity and Selectivity.

In this work, a ratiometric electrochemical sensor was constructed for the detection of Pb2+ based on a bismuth nanocluster-anchored porous activated biochar (BiNCs@AB) composite. BiNCs with loose structure and AB with abundant oxygen-containing functional groups are favorable for Pb2+ adsorption and preconcentration; meanwhile, porous AB provides more mass transfer pathways and increases electronic and ion diffusion coefficients, realizing high sensitivity for Pb2+ detection. At the same time, BiNCs were proposed as an inner reference for ratiometric electrochemical detection, which could greatly enhance the determination accuracy. Under optimized experimental conditions, the anodic peak current ratio between Pb2+ and BiNCs exhibited a good linear relationship with the concentration from 3.0 ng/L to 1.0 mg/L. The detection limit can be detected down to 1.0 ng/L. Furthermore, the proposed sensor demonstrated good reproducibility, stability, and interference resistance, as well as satisfactory recoveries for the detection of Pb2+ in real samples.

Characterization of the complete plastid genome sequence of Breynia fruticosa (L.) Müll.Arg. (Phyllanthaceae), a traditional Chinese medicine plant.

Breynia fruticosa (L.) Müll.Arg. is a well-known folk medicinal plant and found abundantly in South China. The complete chloroplast genome of B. fruticosa reported firstly here was 155,630 bp in length, including a large single-copy region with 85,065 bp (LSC), a small single-copy region with 19,441 bp (SSC) and a pair of inverted repeats with 25, 562 bp (IRa and IRb). The plastome was comprised of 112 distinct genes, with 78 protein coding genes, four ribosomal RNA genes and 30 transfer RNA genes. The overall GC content of B. fruticose chloroplast genome was 36.7%. Phylogenetic analysis revealed that B. fruticosa was closely related to Glochidion fruticosa.

Complete chloroplast genome of Castanopsis sclerophylla (Lindl.) Schott: Genome structure and comparative and phylogenetic analysis.

Castanopsis sclerophylla (Lindl.) Schott is an important species of evergreen broad-leaved tree in subtropical areas and has high ecological and economic value. However, there are few studies on its chloroplast genome. In this study, the complete chloroplast genome sequence of C. sclerophylla was determined using the Illumina HiSeq 2500 platform. The complete chloroplast genome of C. sclerophylla is 160,497 bp long, including a pair of inverted repeat (IR) regions (25,675 bp) separated by a large single-copy (LSC) region of 90,255 bp and a small single-copy (SSC) region of 18,892 bp. The overall GC content of the chloroplast genome is 36.82%. A total of 131 genes were found; of these, 111 genes are unique and annotated, including 79 protein-coding genes, 27 transfer RNA genes (tRNAs), and four ribosomal RNA genes (rRNAs). Twenty-one genes were found to be duplicated in the IR regions. Comparative analysis indicated that IR contraction might be the reason for the smaller chloroplast genome of C. sclerophylla compared to three congeneric species. Sequence analysis indicated that the LSC and SSC regions are more divergent than IR regions within Castanopsis; furthermore, greater divergence was found in noncoding regions than in coding regions. The maximum likelihood phylogenetic analysis showed that four species of the genus Castanopsis form a monophyletic clade and that C. sclerophylla is closely related to Castanopsis hainanensis with strong bootstrap values. These results not only provide a basic understanding of Castanopsis chloroplast genomes, but also illuminate Castanopsis species evolution within the Fagaceae family. Furthermore, these findings will be valuable for future studies of genetic diversity and enhance our understanding of the phylogenetic evolution of Castanopsis.

Effects of biogas slurry fertilization on fruit economic traits and soil nutrients of Camellia oleifera Abel.

Camellia oleifera Abel (C. oleifera) absorb nutrients from surrounding soils and its yield is highly influenced by these nutrients and by fertilizer application. Thus, the soil nutrients play a central role in C. oleifera production. This study investigated the effects of biogas slurry applications on soil nutrients and economic traits of C. oleifera fruits. Five different amounts of biogas slurry (0, 10, 20, 30, or 40 kg/plant/year, three applications per year) were used as fertilizer for C. oleifera plants in 2015 and 2016. The nutrients of rhizosphere soil and the economic traits, including fruit yield, seed rate, and oil yield of C. oleifera fruit, were measured each year. The results showed that fertilization with biogas slurry significantly increased soil organic matter, available nitrogen (N), phosphorus (P), and potassium (K) both in 2015 and 2016. Increases in soil available N, P, and K were maximal in the highest slurry application group followed by the second highest application group. The oil yield correlated with the content of soil available P in both 2015 and 2016, and with soil organic matter in 2015. Fertilization with biogas slurry decreased the saturated fatty acid content in fruit but had no effect on the unsaturated fatty acid content. In conclusion, fertilization with biogas slurry increased rhizosphere soil nutrients and fruit economic traits of C. oleifera and rates of at least30 kg/plant/year had the most positive effects. This study expands the knowledge of fertilization with biogas slurry in C. oleifera production.

Effects of biochar and dicyandiamide combination on nitrous oxide emissions from Camellia oleifera field soil.

Greenhouse gas emissions from agricultural soils contribute substantially to global atmospheric composition. Nitrous oxide (N2O) is one important greenhouse gas induces global warming. Nitrification inhibitors (NI) or biochar can be effective soil N2O emission mitigation strategies for agricultural soils. However, due to differences in crop physiological traits or agricultural management, the effectiveness of mitigation strategies varies among agricultural systems. Camellia oleifera is a woody oil plant widely grown and requires intensive N input, which will potentially increase N2O emissions. Thereby, mitigation of N2O emissions from C. oleifera field soil is vital for sustainable C. oleifera development. Besides NI, incorporation of C. oleifera fruit shell-derived biochar into its soil will benefit waste management and simultaneous mitigation of N2O emissions but this has not been investigated. Here, we conducted two studies to examine effects of biochar addition and NI (dicyandiamide, DCD) application on N2O emissions from C. oleifera field soil with different N (urea or NH4NO3) and incubation temperatures. Biochar effects on nitrification rates varied among N treatments. Biochar applied in combination with DCD further reduced nitrification rates (for urea treatment, decreased from 1.1 to 0.3 mg kg-1 day-1). Biochar addition consistently increased soil N2O emissions (for urea treatment, increased from 0.03 to 0.08 ng g-1 h-1) and their temperature sensitivity. DCD application reduced soil N2O emissions with greater reductions with urea application. In future cultivation of intensively managed C. oleifera gardens, NI should be applied to mitigate N2O emissions if biochar is added, especially when urea is used.

Relationship Between Carbohydrate Antigen 125 and Coronary Artery Calcification in Patients without Known Coronary Artery Disease.

BACKGROUND This study was designed to investigate the association between serum carbohydrate antigen 125 (CA125) and coronary artery calcification (CAC) score in patients without known coronary artery disease. MATERIAL AND METHODS The study groups included 348 consecutive subjects with chest pain but without known coronary artery disease, and who underwent an estimation of CAC score in our hospital. RESULTS The clinical and laboratory characteristics of all subjects are presented according to serum CA125 concentrations tertiles. The CAC score was found to be increased in the tertiles (31.6 ±82.10, 73.3±125.6, 122.9±135.9 U/mL, p<0.001). Serum CA125 concentrations are increased in calcium-positive patients compared with calcium-negative ones (9.3±4.79 vs. 11.2±7.36, p=0.003). A positive correlation between serum CA125 and CAC score was observed (r=0.319, p<0.001) in all participants. Similarly, the serum concentrations of CA125 were found to be positively correlated with CAC score in both women and men (r=0.328, p<0.001; r=0.265, p=0.001, respectively). Multiple linear regression analysis results indicated that serum CA125 concentrations are independently related to CAC score in the study population (beta=0.173, p=0.001), and age, sex, diabetes mellitus, and high-sensitivity C-reactive protein (hs-CRP) were also associated with CAC score in multiple linear regression analysis. CONCLUSIONS Serum CA125 concentrations are correlated with CAC score in the population without known coronary artery disease, and serum CA125 may be considered as a marker to estimate CAC in the study population.

Acute multivessel coronary artery occlusion: a case report.

BACKGROUND: In terms of clinical and angiographic findings, multiple simultaneous coronary occlusions in acute myocardial infarction are infrequent, and the mechanism of the occlusions is unclear. CASE PRESENTATION: We herein report a rare case of two simultaneously occluded coronary arteries, one of which subsequently underwent spontaneous lysis. An 88-year-old man had a 3-hour attack of acute crushing retrosternal chest pain. His first electrocardiogram showed ST-segment elevation in the inferior (II, III, and aVF) and anterior (V3-V6) leads. His second electrocardiogram in the cardiac care unit showed ST-segment elevation in the inferior leads but ST-segment depression in the anterior leads. Emergency coronary angiography revealed that the right coronary artery was acutely and totally occluded at the midportion and that the proximal and midportion of the left anterior descending coronary artery had an acute thrombus. According to his electrocardiogram and coronary angiography findings, we inferred that the right coronary artery and left anterior descending coronary artery first totally occluded simultaneously, and then the thrombus in the left anterior descending coronary artery spontaneously underwent partial lysis. Therefore, intervention of the right coronary artery was performed followed by injection of glycoprotein IIB-IIIA inhibitor into the left anterior descending coronary artery. He had an uneventful hospital course and was discharged home 10 days later. CONCLUSION: Because patients with multivessel coronary artery occlusion are often in serious condition, abnormal electrocardiographic results must be identified and affected vessel should be opened timely and efficiently to save the myocardium and reduce complications such as congestive heart failure.

[Regeneration of transgenic Lespedeza thunbergii expressing levansucrase gene (Sac B) from Bacillus subtilis].

The Bacillus subtilis Sac B gene with the vacuolar targeting signal sequence driven by 35S promotor was transferred into Lespedeza thunbergii by Agrobacterium mediated method. Total 62 Kan-resistant plants were obtained, of which 5 plants were proved to be transgenic plants. The transgenic plants were characterized by PCR amplification, PCR-Southern hybridization and RT-PCR. The physiological assay results showed that the transgenic plants were more tolerant to stress than the controls under the condition of 200mmol/L NaCl and 5% PEG, respectively, and that the content of soluble sugar in trnsgenic plants was significantly higher than that of controls in the period of tests (5-15 days) under salt and PEG stress.

Taurine may prevent diabetic rats from developing cardiomyopathy also by downregulating angiotensin II type2 receptor expression.

OBJECTIVE: In diabetes, intracellular accumulation of sorbitol resulting from the high extracellular levels of glucose leads to depletion of intracellular compounds including taurine. This is associated with the development of late diabetic complications such as cardiomyopathy. The development of myocyte hypertrophy has been largely attributed to angiotensin II, whose growth properties are antagonized by taurine. However, the interaction between taurine, angiotensin II type2 receptor (AT2) and cardiomyopathy related to angiotensin II is still unknown. This study investigates the roles of taurine and AT2 in rats with streptozotocin (STZ)-induced diabetic cardiomyopathy. METHODS: Of 60 female 4-week-old Wistar rats, 8 were treated with common diet and the other 52 with high sugar/fat diet (during the whole experiment) to induce insulin resistance. At the 4th week, of the 52 rats, 7 treated with sodium citrate buffer (pH = 4.5) were grouped into control group1 (con1) and the other 45 were treated by intraperitoneal injection (I.P) with STZ to develop type 2 diabetes. At the 28th week, the maximal velocity decrease of pressure per second in left ventricle within the period of isovolumic relaxation (-dp/dt(max)) was detected by a cannula through right carotid artery. After the cannula operation, of the 45 rats, all the living 24 with -dp/dt(max)< or = 5250 mmHg/s, who had developed diabetic cardiomyopathy, were grouped as follows: 7 treated with double distilled H2O (I.P) were grouped into control group2 (con2). 8 treated with AT2 agonist (CGP42112A) (I.P) were grouped into experimental group1 (exp1). Another 9 treated with taurine (I.P) were grouped into experimental group2 (exp2). All injections lasted 4 weeks (Q.D) and the heart weight (HW) was recorded. To examine cardiomyocyte apoptosis index (CAI), mRNA and protein of AT2 and Bcl-2 in cardiomyocytes, methods of terminal-deoxynucltidyl transferase mediated nick end labeling (TUNEL), reversal transcription polymerase chain reaction (RT-PCR) and immunoblot (Western Blot) were used, respectively. RESULTS: Values of -dp/dt(max) in exp1, exp2 or con2 were much less than those in con1, respectively (p < 0.01). CAI (= stained cell number/total cell number x 100%) and AT2 values both in mRNA and protein levels in con1 were less than those in the other three groups, respectively (p < 0.01). The three parameters above were more in exp1 but less in exp2 than those in con2, respectively (p < 0.01). The three parameters and HW in exp1 were much higher than those in exp2, respectively (p < 0.01). Changes of Bcl-2 were opposed to those of AT2. CONCLUSIONS: A high expression of AT2 may accelerate the apoptosis of cardiomyocytes in diabetic rats and play a role in precipitating diabetic cardiomyopathy; taurine may protect diabetic rats from developing cardiomyopathy also by downregulating AT2 receptors.