Biochar Mitigates the Negative Effects of Microplastics on Sugarcane Growth by Altering Soil Nutrients and Microbial Community Structure and Function.

Microplastic pollution in sugarcane areas of China is severe, and reducing the ecological risks is critical. Biochar has been widely used in soil remediation. This study aims to explore the effects and mechanisms of microplastics combined with or without biochar on sugarcane biomass, soil biochemical properties in red soil through a potted experiment. The results show that, compared with control (CK), treatments with microplastics alone reduced the dry biomass of sugarcane, soil pH, and nitrogen (N) and phosphorus (P) contents by an average of 8.8%, 2.1%, 1.1%, and 2.0%, respectively. Interestingly, microplastics combined with biochar could alleviate the negative effects of microplastic accumulation on sugarcane growth and soil quality. There were significant differences in the bacterial community alpha diversity indices and compositions among different treatments. Compared with CK, treatments with microplastics alone obviously decreased the observed operational taxonomic units (OTUs) and the Chao1 and Shannon indices of soil total bacteria (16S rRNA gene-based bacteria) while increasing them in phoD-harboring bacteria. Microplastics combined with biochar treatments significantly increased the abundance of Subgroup_10 for the 16S rRNA gene and treatments with microplastics alone significantly increased the relative abundance of Streptomyces for the phoD gene compared to CK. Moreover, compared with microplastics alone, the treatments with microplastics combined with biochar increased the relative abundance of Subgroup_10, Bacillus, Pseudomonas in soil total bacteria, and Amycolatopsis and Bradyrhizobium in phoD-harboring bacteria, most of which can inhibit harmful bacteria and promote plant growth. Additionally, different treatments also changed the abundance of potential microbial functional genes. Compared to CK, other treatments increased the abundance of aerobic ammonia oxidation and denitrification but decreased the abundance of nitrate respiration and nitrogen respiration; meanwhile, these four functional genes involved in N cycling processes were obviously higher in treatments with microplastics combined with biochar than in treatments with microplastics alone. In conclusion, microplastics combined with biochar could alleviate the negative effects of microplastic accumulation on sugarcane biomass by altering soil nutrients and microbial community structure and function.

Long-term fertilization has different impacts on bacterial communities and phosphorus forms in sugarcane rhizosphere and bulk soils under low-P stress.

The application of phosphorus (P) fertilizer effectively improves soil P availability, but it also affects soil microbial communities. However, the responses of soil bacterial communities and P forms to long-term P fertilization, and the relationships of bacterial communities with soil P forms remain unclear in P-deficient field. In this study, the impacts of different P fertilization treatments (chemical nitrogen and potassium (NK); chemical N, P and K (NPK); and NPK plus straw (NPKS)) on the bacterial communities and P forms in sugarcane rhizosphere (RS) and bulk soils (BS) were evaluated. Compared with the NK, the NPK and NPKS treatments significantly (P<0.05) increased the yield and quality characters of sugarcane, especially under NPKS. Additionally, P fertilization significantly increased the available P (AP), soluble inorganic P (Pi) and retained Pi in both the RS and BS, but they significantly increased the Chao1 and Shannon index only in the BS; and almost all these indices were significantly higher in the RS than in the BS. The bacterial community compositions were also significantly altered by P fertilization, with major changes in the RS and minor changes in the BS. The bacterial genera that were enriched in the sugarcane rhizosphere mainly included Bradyrhizobium, Rhodanobacter, Pseudolabrys, Conexibacter, and Burkholderia-Caballeronia-Paraburkholderia, some of which potentially promote the plant growth. Compared to NK, functional groups involved in the cycling of carbon, N, and sulfur significantly increased or decreased with fertilizer P application. Moreover, the relative abundances of many bacterial species were significantly correlated with the soil P forms. In conclusion, long-term P fertilization altered bacterial structure and functions in P-deficient sugarcane soil, which could help the soil P cycling and suppling. The results provide useful information to stimulate the power of the microbes by fertilization measures to improve soil nutrients and crop production.

Effects of Seaweed Extracts on the Growth, Physiological Activity, Cane Yield and Sucrose Content of Sugarcane in China.

Seaweed extracts (SEs) have been widely used as biostimulants in crop management due to their growth-promoting and stress-resistant effects. To date, there are few reports of the effect of SEs on sucrose content and cane yield. Here, we conducted field experiments for three consecutive growth seasons (2017∼2019) in two areas (Suixi and Wengyuan) of China, to investigate the yield and sugar content of sugarcane in response to SE treatment at different growth stages. The results showed that spraying SEs once at seedling (S), early elongation (E), and early mature (M) stages, respectively, once at S and E stages, respectively, or once at the S stage increased the cane yield by 9.23, 9.01, and 3.33%, respectively, implying that SEs application at the early elongation stage played a vital role in promoting sugarcane growth. Photosynthetic parameters and nutrient efficiency analysis showed that spraying SEs at S and E stages enhanced the net photosynthetic rate, transpiration rate, and water use efficiency, and increased N, P, or K utilization efficiency, compared with those of the control. Notably, cane yield increasing rate of SEs in 2017 and 2018 were higher than those in 2019 in Wengyuan but lower than those in 2019 in Suixi. Interestingly, the total rainfall and monthly average rainfall in 2017 and 2018 were lower than those in 2019 in Wengyuan but higher than those in 2019 in Suixi. The results suggested that the yield increasing rate of SEs on sugarcane was better in less rainfall years. The sucrose content of sugarcane showed no difference between spraying SEs at the M stage alone or at the three growth stages but was higher than those of SE treatments at S and/or E stages. Enzyme activity analysis showed that spraying SEs at the M stage increased the activity of sucrose phosphate synthase activity by 9.14% in leaves and 15.16% in stems, and decreased soluble acid invertase activity in stems by 16.52%, which contributed to the sucrose increase of 5.00%. The above results suggested that SEs could increase cane yield and promote sucrose accumulation in sugarcane. The yield increasing effect was more obvious under conditions of drought stress.

Pregnancy outcomes in different stages of systemic lupus erythematosus among Chinese women - a retrospective cohort study.

OBJECTIVES: To analyze the outcomes of pregnancies and risk factors in Chinese women with different stages of systemic lupus erythematosus (SLE). MATERIAL AND METHODS: A total of 55 conceptions in 52 patients with SLE between Jan 2007 and Jan 2019 were retrospected systematically from a general hospital graded 3A in China. Medical records provided us a good way to retrieve the clinical parameters and lab data of patients. RESULTS: Pregnant women with SLE activity had significant hyperimmunoglobulin, hypocomplement, low platelet counts, high erythrocyte sedimentation rate, C-reactive protein and 24-h urine protein. Hydroxychloroquine had been used to reduce the rates of SLE activity in pregnant women. Logistic regression analysis showed low platelet counts, hypocomplement and 24-h urine protein were significantly correlated with fetal loss. Compared to those in stable stage, the active SLE patients have more risks of hypertensive disorders of pregnancy, thrombocytopenia, lupus nephritis and placental infarction, and have worse fetal outcomes, including the higher rate of fetal loss, preterm and asphyxia neonatorum. CONCLUSIONS: Different stages of SLE during pregnancy are closely related to maternal and fetal outcomes. It is imperative to provide SLE women with pregnancy consultation and regular multispecialty care.

Characterization of a novel PL 17 family alginate lyase with exolytic and endolytic cleavage activity from marine bacterium Microbulbifer sp. SH-1.

Alginate lyases are essential tools for depolymerizing alginate into bioactive oligosaccharides and fermentable monosaccharides. Herein, we characterized a novel polysaccharide lyase AlgSH17 from marine bacterium Microbulbifer sp. SH-1. The recombinant enzyme exhibited the maximum activity at 30 °C, pH 7.0 and retained 86.20% and 65.43% of its maximum activity at 20 °C and 15 °C, respectively, indicating that AlgSH17 has an excellent cold-adapted property. The final products of AlgSH17 mainly consisted of monosaccharides with small amounts of oligosaccharides with degrees of polymerization (DP) 2-6, suggesting that AlgSH17 possesses both exolytic and endolytic activity. Degradation pattern analysis indicated that AlgSH17 could degrade DP ≥ 4 oligosaccharides into disaccharides and trisaccharides by cleaving the endo-glycosidic bonds and further digest disaccharides and trisaccharides into monosaccharides in an exolytic manner. Products distribution and molecular docking analysis revealed that AlgSH17 could cleave the glycosidic bonds between -1 and +2 within the substrate. Furthermore, The ABTS+, hydroxyl and DPPH radicals scavenging activity of the enzymatic hydrolysates prepared by AlgSH17 reached up to 91.53%, 81.23% and 61.06%, respectively, and the enzymatic hydrolysates displayed an excellent preservation effect on fresh-cut apples. The above results suggested that AlgSH17 could be utilized for the production of monosaccharides, antioxidants and food additives.

Shallower Root Spatial Distribution Induced by Phosphorus Deficiency Contributes to Topsoil Foraging and Low Phosphorus Adaption in Sugarcane (Saccharum officinarum L.).

Low phosphorus (P) availability in acid soils is one of the main limiting factors in sugarcane (Saccharum officinarum L.) production. Reconstruction of the root system architecture (RSA) is a vital mechanism for crop low P adaption, while the RSA of sugarcane has not been studied in detail because of its complex root system. In this study, reconstruction of the RSA and its relationship with P acquisition were investigated in a P-efficient sugarcane genotype ROC22 (R22) and two P-inefficient genotypes Yunzhe 03-103 (YZ) and Japan 2 (JP). An efficient dynamic observation room was developed to monitor the spatiotemporal alternation of sugarcane root length density (RLD) and root distribution in soil with heterogeneous P locations. The sugarcane RSA was reconstructed under P deficiency, and R22 had an earlier response than YZ and JP and presented an obvious feature of root shallowness. Compared with the normal P condition, the shallow RLD was increased by 112% in R22 under P deficiency while decreased by 26% in YZ and not modified in JP. Meanwhile, R22 exhibited a shallower root distribution than YZ and JP under P deficiency, supported by 51 and 24% greater shallow RLD, and 96 and 67% greater shallow root weight, respectively. The ratio of shallow RLD to total RLD in R22 was 91% greater than YZ, and the ratio of shallow root weight to total root weight in R22 was greater than that of YZ and JP by 94 and 30%, respectively. As a result, R22 had a higher shoot P accumulation than YZ and JP, which thereby increased the relative leaf sheath inorganic P concentration (RLPC) by 47 and 56%, relative shoot biomass (RSB) by 36 and 33%, and relative cane weight (RCW) by 31 and 36%, compared with YZ and JP under P deficiency, respectively. We verified the reliability and efficiency of a dynamic observation room and demonstrated that a shallower root distribution contributed to improving topsoil foraging, P acquisition, and low P adaption under P deficiency in sugarcane. Therefore, a shallower root distribution merits consideration as an evaluation trait for breeding P efficient sugarcane genotypes and genetic improvement.

Purification and Characterization of a Novel Endolytic Alginate Lyase from Microbulbifer sp. SH-1 and Its Agricultural Application.

Alginate, an important acidic polysaccharide in marine multicellular algae, has attracted attention as a promising biomass resource for the production of medical and agricultural chemicals. Alginate lyase is critical for saccharification and utilization of alginate. Discovering appropriate and efficient enzymes for depolymerizing alginate into fermentable fractions plays a vital role in alginate commercial exploitation. Herein, a unique alginate lyase, AlgSH7, belonging to polysaccharide lyase 7 family is purified and characterized from an alginate-utilizing bacterium Microbulbifer sp. SH-1. The purified AlgSH7 shows a specific activity of 12,908.26 U/mg, and its molecular weight is approximately 66.4 kDa. The optimal temperature and pH of AlgSH7 are 40 °C and pH 9.0, respectively. The enzyme exhibits stability at temperatures below 30 °C and within an extensive pH range of 5.0-9.0. Metal ions including Na+, K+, Al3+, and Fe3+ considerably enhance the activity of the enzyme. AlgSH7 displays a preference for poly-mannuronic acid (polyM) and a very low activity towards poly-guluronic acid (polyG). TLC and ESI-MS analysis indicated that the enzymatic hydrolysates mainly include disaccharides, trisaccharides, and tetrasaccharides. Noteworthy, the alginate oligosaccharides (AOS) prepared by AlgSH7 have an eliciting activity against chilling stress in Chinese flowering cabbage (Brassica parachinensis L.). These results suggest that AlgSH7 has a great potential to design an effective process for the production of alginate oligomers for agricultural applications.

Effects of Nitrogen and Phosphorus Inputs on Soil Bacterial Abundance, Diversity, and Community Composition in Chinese Fir Plantations.

Nutrient inputs to forest ecosystems significantly influence aboveground plant community structure and ecosystem functioning. However, our knowledge of the influence of nitrogen (N) and/or phosphorus (P) inputs on belowground microbial communities in subtropical forests is still unclear. In this study, we used quantitative polymerase chain reaction and Illumina Miseq sequencing of the bacterial 16S rRNA gene to investigate bacterial abundance, diversity, and community composition in a Chinese fir plantation. The fertilization regimes were as follows: untreated control (CK), P amendment (P), N amendment (N), and N with P amendment (NP). Additions of N decreased soil pH and bacterial 16S rRNA gene abundance by 3.95 (from 4.69 to 3.95) and 3.95 × 109 copies g-1 dry soil (from 9.27 × 109 to 3.95 × 109 g-1 dry soil), respectively. Bacterial richness and diversity decreased with N addition (N and NP) rather than only P input. Proteobacteria, Acidobacteria, and Actinobacteria were the major phylum across all treatments. Nitrogen addition increased the relative abundance of Proteobacteria and Actinobacteria by 42.0 and 10.5%, respectively, while it reduced that of Acidobacteria by 26.5%. Bacterial community structure in the CK and P treatments was different from that in the N and NP treatments upon principle coordinates analysis. Phosphorus addition did not significantly affect soil bacterial communities, and no interactions between N and P inputs on microbial traits were observed. Soil pH and mineral N availability appeared to have a cooperative effect on bacterial abundance and community structure, with soil pH being the key influencing factor by canonical correspondence analysis. These results indicate that inorganic N rather than P fertilization affected both bacterial abundance and community composition in subtropical forests.

Expression of Angiopoietin and VEGF in Cervical Cancer and its Clinical Significance.

OBJECTIVE: The aim of this study was to evaluate the expression of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF) in cervical cancer and its clinical significance. METHODS: Immunohistochemical assay was used to examine the expression of Ang-1/2 and VEGF in tumor tissue from 56 cervical squamous cell carcinoma patients treated with operation only (SCC-O group), as well as 51 subjects with cervical squamous cell carcinoma treated with neoadjuvant radiotherapy (SCC-RCO group, n=28) or neoadjuvant chemotherapy (SCC-CO group, n=23). Both microvessel density (MVD) and lymphatic vessel density (LVD) were examined in the three groups through detection of CD34 and D2-40 expression in respective tissue samples. RESULTS: With the progression of cervical cancer, the positive expression scores of Ang-2 and VEGF were significantly increased (p<0.05). Compared with surgical intervention, neoadjuvant chemoradiotherapy significantly reduced the positive expression scores of Ang-1, Ang-2, and VEGF in cervical cancer tissues (p<0.05). The MVD values of the SCC-CO and SCC-RO groups were significantly reduced as compared to the SCC-O group (p<0.05). Similarly, the LVD values of the SCC-CO and SCC-RO groups were also significantly reduced when compared to those of the SCC-O group (p<0.05). However, LVD values of the SCC-CO and SCC-RO groups were not statistical different (p>0.05). CONCLUSION: Ang-1, Ang-2 and VEGF may play an important role in the development of cervical cancer. Mutual synergism of Ang-2 and VEGF demonstrated a close relationship with the generation of cervical blood and lymphatic vessels. Cervical cancer radiotherapy and chemotherapy could significantly inhibit the formation of blood vessels and lymphatic vessels in tumor tissue.

Influence of nitrogen and phosphorus additions on N2-fixation activity, abundance, and composition of diazotrophic communities in a Chinese fir plantation.

Although biological nitrogen (N) fixation (BNF) is an important N input process in subtropical forest ecosystems, how the diazotrophic communities related to this process respond to N and phosphorus (P) inputs is largely unknown. We investigated the effects of exogenous N and/or P inputs on N2-fixation activity, diazotrophic abundance and community composition using a continuous application of fertilizers over 5years experiment in a Chinese fir plantation. The fertilization regimes included control (CK), P treatment (P), low N addition treatment (N1), high N addition treatment (N2), low N and P addition treatment (N1P) and high N with P addition treatment (N2P). N2-fixation activity was determined using the acetylene reduction assay (ARA). Quantitative PCR and Illumina Miseq sequencing of nifH gene were performed to analyze diazotrophic abundance and community composition, respectively. Our results showed that P addition increased N2-fixation activity and nifH gene abundance by 189.07nmol C2H4 and 1.02×107copiesg-1 dry soil, respectively, while were reduced by 1.19nmol C2H4 and 2.04×106copiesg-1 dry soil when N was added. The application of P with low N (N1P) effectively alleviated the inhibitory effect of N input on N2-fixation activity. N-related treatments resulted in significant decreases in operational taxonomic unit (OTU) richness and shifts in diazotrophic community structure. N2-fixation activity and nifH gene abundance were strongly and positively correlated with soil pH and negatively correlated with mineral N (NH4+-N and NO3--N) contents, while mineral N concentrations rather than soil pH appeared to be the main factor altering diazotrophic community structure. These results revealed that P addition played a positive role in regulating biological nitrogen fixation in subtropical forest ecosystems.