[Analysis on the Current Situation of Phytoplankton in the Typical River-Lake Ecotone of Lake Poyang].

The typical river-lake ecotone (tail end area) of Poyang Lake, which is a sensitive area and prone to outbreaks of cyanobacteria bloom, is vulnerable to frequent human activities. To explore the diversity of phytoplankton community structure and the relevant driving mechanism in the typical river lake junction area of Poyang Lake, the water quality and phytoplankton at seven sampling points in the typical river lake junction area of Poyang Lake, at six sampling points in the middle section of Poyang Lake River, and at one sampling point in the main lake area were investigated in the field from 2019 to 2020 (dry season), April (flood season), July (wet season), and October (recession period). The results showed that there were seven phyla and 64 genera of phytoplankton in the typical river-lake ecotone of Poyang Lake, and the biomass and relative abundance of phytoplankton were dominated by diatoms and cyanobacteria. The biomass and abundance in the east of the typical river-lake ecotone of Poyang Lake were generally higher than those in the west, and the biomass and abundance in the river-lake ecotone were higher than those in the middle of the river. The dominant degree of cyanobacteria in the lake area and the river-lake ecotone was large, and the dominant degree of diatoms in the middle section of the river was large. The Monte Carlo test results showed that total nitrogen (TN), total phosphorus (TP), orthophosphate phosphorus (PO43--P), water depth (WD), water temperature (WT), and transparency (SD) were significantly related environmental factors affecting the distribution of the phytoplankton community. Redundancy analysis results showed that the typical river-lake ecotone in the west of Poyang Lake was highly affected by the hydration factors (TN, TP, and PO43--P), and the hydrological factors (WT, WD, and SD) in the typical river-lake ecotone in the east were highly significant. The impact factors of phytoplankton in the typical river-lake ecotone of Poyang Lake were seasonal, being greatly affected by hydration factors in winter and hydrological factors in summer.

Forest gaps regulate seed germination rate and radicle growth of an endangered plant species in a subtropical natural forest.

The survival rate of Castanopsis kawakamii from seed to seedling is relatively low, leading to difficulties in the regeneration of its natural forests. Forest gaps play a vital role in plant regeneration and biodiversity maintenance in forest ecosystems. Unfortunately, our understanding of the effects of gap size and within-gap position on the seed germination and radicle growth of C. kawakamii is still limited. In particular, our knowledge on the relationship between gap size and environmental factors and their influence on seed germination and radicle growth is incomplete. In the present study, we studied the influences of forest gaps and within-gap position on seed regeneration on the germination and radicle growth of an endangered species C. kawakamii in a subtropical natural forest in China. We selected three large gaps (LG, gap size above 200 m2), three medium gaps (MG, gap size 50-100 m2), three small gaps (SG, gap size 30-50 m2), and non-gap (NG), and planted the seeds of C. kawakamii in five positions within each gap. The results showed that (1) the influence of forest gaps on seed germination rate was, from highest to lowest, medium gaps (51%), non-gap (47%), small gaps (40%) and large gaps (17%), and the seed germination rate was the highest in all positions in medium gaps, with the exception of the east position. (2) Radicle length in forest gaps was, from highest to lowest, medium gaps, small gaps, large gaps and non-gap, and it was the highest in the east, south, west and north positions of medium gaps. (3) Canopy openness (gap size) and air temperature were the main factors influencing seed germination and radicle growth of C. kawakamii. We concluded that medium-sized gaps were the most suitable for seed germination and radicle growth of C. kawakamii, and they promote the regeneration of this endangered species in the investigated natural forest.

[Responses of chlorophyll fluorescence and non-structural carbohydrate accumulation of Castanopsis kawakamii seedlings to seed dispersal positions]. / æ ¼æ°æ ²å¹¼è‹—å¶ç»¿ç´ è§å ‰å’Œéžç»“æž„æ€§ç¢³æ°´åŒ–åˆç‰©ç§¯ç´¯å¯¹ç§å­æ•£å¸ƒä½ç½®çš„å“åº”.

When seeds fallen from the mother trees, their initial contact physical environment was litter or soil. The dispersal positions of seeds (seeds positioned on top of the litter, the soil surface and beneath the litter) determine the process of their natural regeneration. We simulated three different dispersal positions of Castanopsis kawakamii, including seeds positioned on top of the litter (2 and 4 cm litter was placed below the seed layer), soil surface (without litter), and seeds beneath the litter (2, 4, 6 and 8 cm litter covers in the upper layer of seeds). We examined the effects of seed dispersal position on the chlorophyll fluorescence characteristics, non-structural carbohydrate, specific leaf area, leaf dry matter content and nutrient content of seedlings. The results showed that leaf nitrogen content per area of seedlings had significantly positive correlation with soluble sugar content, non-structural carbohydrate content, and negative correlation with specific leaf area across different dispersal positions. Seedlings of the moderate litter cover (2 and 4 cm) adopted resource acquisitive strategies by increasing relative chlorophyll content, soluble sugar content, non-structural carbohydrate content, leaf dry matter content, leaf nitrogen content and phosphorus contents per area, and decreasing specific leaf area to achieve their demands for rapid growth. Seedlings grew on soil surface and beneath the deep litter (6 and 8 cm) adopted the resource conservative strategies with higher leaf nitrogen content per mass and specific leaf area, lower leaf dry matter content, and non-structural carbohydrate content to intercept more effective light resources to compensate for the shady environment brought by deep litter. This would further decrease the probability of seedling mortality due to 'carbon starvation'. Seedlings under litter layer stored starch in leaf, and reduced the energy consumption of photosynthetic tissues (low PSⅡ maximum photochemical efficiency) to maintain seedling growth. Comprehensive analysis of entropy method indicated that low amount of litter cover (2 cm) significantly promoted seedling growth of C. kawakamii. In the future, we could regulate the thickness of litter layer to promote the growth and regeneration of C. kawakamii seedlings in natural forest.

Complement C1q (C1qA, C1qB, and C1qC) May Be a Potential Prognostic Factor and an Index of Tumor Microenvironment Remodeling in Osteosarcoma.

The tumor microenvironment (TME) has important effects on the tumorigenesis and development of osteosarcoma (OS). However, the dynamic mechanism regulating TME immune and matrix components remains unclear. In this study, we collected quantitative data on the gene expression of 88 OS samples from The Cancer Genome Atlas (TCGA) database and downloaded relevant clinical cases of OS from the TARGET database. The proportions of tumor-infiltrating immune cells (TICs) and the numbers of immune and matrix components were determined by CIBERSORT and ESTIMATE calculation methods. Protein-protein interaction (PPI) network construction and Cox regression analysis were conducted to analyze differentially expressed genes (DEGs). The complement components C1qA, C1qB and C1qC were then determined to be predictive factors through univariate Cox analysis and PPI cross analysis. Further analysis found that the levels of C1qA, C1qB and C1qC expression were positively linked to OS patient survival time and negatively correlated with the clinicopathological feature percent necrosis at definitive surgery. The results of gene set enrichment analysis (GSEA) demonstrated that genes related to immune functions were significantly enriched in the high C1qA, C1qB and C1qC expression groups. Proportion analysis of TICs by CIBERSORT showed that the levels of C1qA, C1qB and C1qC expression were positively related to M1 and M2 macrophages and CD8+ cells and negatively correlated with M0 macrophages. These results further support the influence of the levels of C1qA, C1qB and C1qC expression on the immune activity of the TME. Therefore, C1qA, C1qB and C1qC may be potential indicators of remodeling in the OS TME, which is helpful to predict the prognosis of patients with OS and provide new ideas for immunotherapy for OS.

[Population status and protection evaluation of Syzygium album, a species with extremely small population.] / 极小种群植物白果蒲桃种群现状与保护评价.

Syzygium album is a plant species with extremely small population and endemic to Yun-xiao County, Fujian Province. We examined its population status and conservation evaluation. The results showed that there were 25 individuals of S. album, with only one mother tree. Except for the mother tree and one small tree, the others were all young seedlings, which was rare in abundance and lack of age stage of middle and strong trees. The spatial distribution of young seedlings was not uniform, with most of individuals within the range of 10-25 m from the mother tree. The age class structure of the population was not continuous and the population development was unsustainable. The competition mainly came from other species. Cryptocarya chinensis accounted for 66.6% of the total competition index, which was much higher than other species. We established a comprehensive evaluation index system for the protection of rare and endangered plants with extremely small populations and evaluated the protection of S. album from three aspects, i.e., endangered degree, protection value, and protection priority. The endangered degree of S. album was level Ⅰ (the endangered degree index was 4.510), belonging to extremely endangered species, the protection value was level Ⅰ (the protection value index was 4.052), which was of great value, and the protection priority was level Ⅰ (the protection priority index was 4.016), which should be listed as the highest priority protection level.

Differential patterns of nitrogen and δ15N in soil and foliar along two urbanized rivers in a subtropical coastal city of southern China.

Urbanization usually pollutes the environment leading to alterations in key biogeochemical cycles. Therefore, understanding its effects on forest nitrogen (N) saturation is becoming increasingly important for addressing N pollution challenges in urban ecosystems. In this study, we compared soil (N availability, net N mineralization, net nitrification, and δ15N) and foliar (N concentrations and δ15N) variables in upstream, midstream and downstream forest stands of Bailongjiang River (BJR; more urbanized) and Wulongjiang River (WJR; less urbanized), the two branches of the Minjiang River Estuary. Total soil N, ammonium, nitrate, net N mineralization and nitrification rates, as well as soil δ15N were significantly higher in BJR compared with WJR forest stands. While no substantial difference in foliar N concentrations was noted between rivers, foliar δ15N was on average more than 2.5 times higher in BJR than WJR forest stands. Across the study area, foliar δ15N was positively related to soil δ15N, which also had positive linear relationships with soil nitrate concentrations, net N mineralization and net nitrification rates. Moreover, all variables except foliar δ15N and ammonium concentrations showed decreasing patterns in the order: upstream > midstream > downstream along the BJR forest stands. Soil ammonium and foliar values (N concentrations and δ15N) revealed clear patterns along the WJR, with the former increasing and the latter decreasing from the upstream to downstream forest stands. Our findings indicate an increase in urbanization-induced N inputs from the WJR to BJR and that forest stands along the BJR especially at the upstream have higher N availability and are shifting rapidly towards N saturation state. These results emphasize the need for effective N pollution control in urban environments through sustainable urban planning.

[Effect of Bifidobacterium on the expression of ß-defensin-2 in intestinal tissue of neonatal rats with necrotizing enterocolitis].

OBJECTIVE: To study the effect of Bifidobacterium on the expression of ß-defensin-2 (BD-2) in intestinal tissue of neonatal rats with necrotizing enterocolitis (NEC). METHODS: A total of 40 rats were randomly divided into four groups: normal control, Bifidobacterium control, NEC model, and Bifidobacterium treatment, with 10 rats in each group. A rat model of NEC was induced by hypoxia, cold stimulation, and artificial feeding. The rats in the Bifidobacterium control and Bifidobacterium treatment groups were given Bifidobacterium via the gastric tube after cold stimulation once a day for three consecutive days. The morphological changes of the terminal ileum were observed under a light microscope and the intestinal injury score was determined. Immunohistochemistry and qRT-PCR were used to measure the protein and mRNA expression of BD-2 in the ileal mucosal tissue. RESULTS: The NEC model group had a significantly higher intestinal injury score than the normal control, Bifidobacterium control, and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium treatment group had a significantly higher intestinal injury score than the normal control and Bifidobacterium control groups (P<0.05). The mRNA and protein expression of BD-2 in the normal control group was significantly lower than in the Bifidobacterium control, NEC model, and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium control group had significantly higher mRNA and protein expression of BD-2 than the NEC model and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium treatment group had significantly higher mRNA and protein expression of BD-2 than the NEC model group (P<0.05). CONCLUSIONS: Bifidobacterium can induce the expression of BD-2 in intestinal tissue of rats and reduce inflammatory response by increasing the expression of BD-2. This provides a protective effect on neonatal rats with NEC.

[Site selection of nature reserve based on the self-learning tabu search algorithm with space-ecology set covering problem: An example from Daiyun Mountain, Southeast China]. / åŸºäºŽç©ºé—´ç”Ÿæ€é›†åˆè¦†ç›–æ¨¡åž‹çš„è‡ªå­¦ä¹ ç¦å¿Œæœç´¢ç®—æ³•åœ¨ä¿æŠ¤åŒºç©ºé—´é€‰å€ä¸­çš„åº”ç”¨­­ä»¥æˆ´äº‘山为例.

Designing the nature reserves is an effective approach to protecting biodiversity. The traditional approaches to designing the nature reserves could only identify the core area for protecting the species without specifying an appropriate land area of the nature reserve. The site selection approaches, which are based on mathematical model, can select part of the land from the planning area to compose the nature reserve and to protect specific species or ecosystem. They are useful approaches to alleviating the contradiction between ecological protection and development. The existing site selection methods do not consider the ecological differences between each unit and has the bottleneck of computational efficiency in optimization algorithm. In this study, we first constructed the ecological value assessment system which was appropriated for forest ecosystem and that was used for calculating ecological value of Daiyun Mountain and for drawing its distribution map. Then, the Ecological Set Covering Problem (ESCP) was established by integrating the ecological values and then the Space-ecology Set Covering Problem (SSCP) was generated based on the spatial compactness of ESCP. Finally, the STS algorithm which possessed good optimizing performance was utilized to search the approximate optimal solution under diverse protection targets, and the optimization solution of the built-up area of Daiyun Mountain was proposed. According to the experimental results, the difference of ecological values in the spatial distribution was obvious. The ecological va-lue of selected sites of ESCP was higher than that of SCP. SSCP could aggregate the sites with high ecological value based on ESCP. From the results, the level of the aggregation increased with the weight of the perimeter. We suggested that the range of the existing reserve could be expanded for about 136 km2 and the site of Tsuga longibracteata should be included, which was located in the northwest of the study area. Our research aimed at providing an optimization scheme for the sustai-nable development of Daiyun Mountain nature reserve and the optimal allocation of land resource, and a novel idea for designing the nature reserve of forest ecosystem in China.

Comparative study on fermentation performance in the genome shuffled Candida versatilis and wild-type salt tolerant yeast strain.

BACKGROUND: The fermentation performance of a genome-shuffled strain of Candida versatilis S3-5, isolated for improved tolerance to salt, and wild-type (WT) strain were analysed. The fermentation parameters, such as growth, reducing sugar, ethanol, organic acids and volatile compounds, were detected during soy sauce fermentation process. RESULTS: The results showed that ethanol produced by the genome shuffled strain S3-5 was increasing at a faster rate and to a greater extent than WT. At the end of the fermentation, malic acid, citric acid and succinic acid formed in tricarboxylic acid cycle after S3-5 treatment elevated by 39.20%, 6.85% and 17.09% compared to WT, respectively. Moreover, flavour compounds such as phenethyl acetate, ethyl vanillate, ethyl acetate, isoamyl acetate, ethyl myristate, ethyl pentadecanoate, ethyl palmitate and phenylacetaldehyde produced by S3-5 were 2.26, 2.12, 2.87, 34.41, 6.32, 13.64, 2.23 and 78.85 times as compared to WT. CONCLUSIONS: S3-5 exhibited enhanced metabolic ability as compared to the wild-type strain, improved conversion of sugars to ethanol, metabolism of organic acid and formation of volatile compounds, especially esters, Moreover, S3-5 might be an ester-flavour type salt-tolerant yeast. © 2016 Society of Chemical Industry.

Non-targeted metabolomic reveals the effect of salt stress on global metabolite of halotolerant yeast Candida versatilis and principal component analysis.

As one of the major microbes in the soy sauce fermentation, Candida versatilis enriches the flavor and improves the quality of soy sauce. In this study, a combination of five different GC-MS and LC-MS-based metabolome analytical approaches was used to analyze the intracellular, extracellular and whole metabolites of C. versatilis. Our results found out that a total of 132, 244 and 267 different metabolites were detectable from the intracellular, extracellular and whole part, respectively. When exposed to 0. 9 and 18 % salt, respectively, 114, 123 and 129 different intracellular metabolites, 184, 200 and 178 extracellular metabolites and 177, 188 and 186 whole metabolites were detected, respectively. Our data showed that salt enhances the metabolic capacity of C. versatilis, especially its amino acid and enhances the synthesis and secretion of some metabolites of C. versatilis, especially the aldehydes and phenols, such as vanillin, guaiacol and 5-hydroxymethylfurfural. Our data also showed that special attention has to be paid to the generation of biogenic amines when C. versatilis was treated with salt.

Effect of salt-tolerant yeast of Candida versatilis and Zygosaccharomyces rouxii on the production of biogenic amines during soy sauce fermentation.

BACKGROUND: This study aimed to enhance and improve the quality and safety of soy sauce. In the present work, the change of biogenic amines, such as histamine, tyramine, cadaverine, spermidine, was examined by the treatment of Candida versatilis and Zygosaccharomyces rouxii, and the influence of salt-tolerant yeast on biogenic amines was analysed during the whole fermentation process. RESULTS: The results showed that the content of biogenic amines was elevated after yeast treatment and the content of biogenic amines was influenced by using yeast. The dominating biogenic amine in soy sauce was tyramine. At the end of fermentation, the concentrations of biogenic amines produced by Zygosaccharomyces rouxii and Candida versatilis in the soy mash were 122.71 mg kg(-1) and 69.96 mg kg(-1) . CONCLUSIONS: The changes of biogenic amines in high-salt liquid soy mash during fermentation process indicated that a variety of biogenic amines were increased in the fermentation ageing period, which may be due to amino acid decarboxylation to form biogenic amines by yeast decarboxylase. The fermentation period of soy sauce should be longer than 5 months because biogenic amines began to decline after this time period.

[Genetic diversity of natural and planted Glyptostrobus pensilis populations: a comparative study].

Glyptostrobus pensilis is a rare and endangered relict species in China. To make a comparative study on the genetic diversity and genetic structure of natural and planted G. pensilis populations would have significance in the conservation and proliferation of the species. Samples from the main distribution regions of G. pensilis were analyzed by ISSR (inter simple sequence repeats) molecular marker. A total of 95 discernible DNA fragments were detected with 10 ISSR primers, of which, polymorphic loci occupied 39.0%, suggesting that the genetic variation in the test G. pensilis populations was at a very low level, compared with other endangered gymnosperm. The genetic differential index (G(st) = 0.3982) and the gene flow (N(m) = 0.3778) indicated that there existed genetic differentiation among populations but the differentiation dominated within populations. There was a significant positive correlation between genetic distance and geographical distance. The mean values of polymorphic loci (P), Nei's gene index (H(e)), and Shannon information index (I) of natural populations (P = 39.9%, H(e) = 0.1499, I = 0.2202) were much higher than those of planted G. pensilis populations (P = 30.7%, H(e) = 0.1265, I = 0.1759), and the coefficient of gene differentiation (G(st)) and genetic distance (D) of natural populations (G(st) = 0.4513, D = 0.0301) were also much higher than those of the planted populations (G(st) = 0.3025, D = 0.0192).

Important role of catalase in the production of ß-carotene by recombinant Saccharomyces cerevisiae under H2O2 stress.

The effect of H(2)O(2) supplement on cell growth and ß-carotene productions in recombinant Saccharomyces cerevisiae CFW-01 and CFW-01 ctt1 deficiency in cytosolic catalase were investigated in shaking flasks. The results showed that supplement of H(2)O(2) (0.5 and 1.0 mM) can significantly stimulate the ß-carotene production. However, ß-carotene levels of CFW-01 ctt1Δ under 0.5 and 1 mM H(2)O(2) were 16.7 and 36.7% lower than those of CFW-01, respectively. Although lacking cytosolic catalase, no significant differences in cell growth were observed between CFW-01 ctt1Δ and CFW-01 under the same level of H(2)O(2) stress. These results suggest that ß-carotene can act as an antioxidant to protect the recombinant yeast from H(2)O(2) oxidative damage in the absence of cytosolic catalase. However, catalase still plays an important role in the production of ß-carotene under H(2)O(2) stress. If catalase can not timely decompose H(2)O(2), the free radicals such as OH· derived from H(2)O(2) can result in decrease of ß-carotene concentration. Therefore, in the production of ß-carotene by H(2)O(2) stress, not only the level of oxidative stress, but also the activities of catalase in cells should be considered.