Predicting potential distribution of Ziziphus spinosa (Bunge) H.H. Hu ex F.H. Chen in China under climate change scenarios.

Ziziphus spinosa (Bunge) H.H. Hu ex F.H. Chen is a woody plant species of the family Rhamnaceae (order Rhamnales) that possesses high nutritional and medicinal value. Predicting the effects of climate change on the distribution of Z. spinosa is of great significance for the investigation, protection, and exploitation of this germplasm resource. For this study, optimized maximum entropy models were employed to predict the distribution patterns and changes of its present (1970-2000) and future (2050s, 2070s, and 2090s) potential suitable regions in China under multiple climate scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 & SSP5-8.5). The results revealed that the total area of the present potential suitable region for Z. spinosa is 162.60 × 104 km2, which accounts for 16.94% of China's territory. Within this area, the regions having low, medium, and high suitability were 80.14 × 104 km2, 81.50 × 104 km2, and 0.96 × 104 km2, respectively, with the high suitability regions being distributed primarily in Shanxi, Hebei, and Beijing Provinces. Except for SSP-1-2.6-2070s, SSP-5-8.5-2070s, and SSP-5-8.5-2090s, the suitable areas for Z. spinosa in the future increased to different degrees. Meanwhile, considering the distribution of Z. spinosa during different periods and under different climate scenarios, our study predicted that the low impact areas of Z. spinosa were mainly restricted to Shanxi, Shaanxi, Ningxia, Gansu, Liaoning, Inner Mongolia, and Jilin Provinces. The results of core distributional shifts showed that, except for SSP1-2.6, the center of the potential suitable region of Z. spinosa exhibited a trend of gradually shifting to the northwest.

Genome-Wide Analysis and the Expression Pattern of the MADS-Box Gene Family in Bletilla striata.

Bletilla striata (Thunb. ex A. Murray) Rchb. f., a species of the perennial herb Orchidaceae, has potent anti-inflammatory and antiviral biological activities. MADS-box transcription factors play critical roles in the various developmental processes of plants. Although this gene family has been extensively investigated in many species, it has not been analyzed for B. striata. In total, 45 MADS-box genes were identified from B. striata in this study, which were classified into five subfamilies (Mδ, MIKC, Mα, Mß, and Mγ). Meanwhile, the highly correlated protein domains, motif compositions, and exon-intron structures of BsMADSs were investigated according to local B. striata databases. Chromosome distribution and synteny analyses revealed that segmental duplication and homologous exchange were the main BsMADSs expansion mechanisms. Further, RT-qPCR analysis revealed that BsMADSs had different expression patterns in response to various stress treatments. Our results provide a potential theoretical basis for further investigation of the functions of MADS genes during the growth of B. striata.

Microbial diversity and community structure changes in the rhizosphere soils of Atractylodes lancea from different planting years.

Atractylodes lancea is a type of typical traditional Chinese medicinal (TCM) herb that is economically important in China. The traditional planting method of A. lancea is to plant in situ continuously for many years, which often leads to impediments for its growth and development and soil-borne diseases. The root-associated microbiome is believed to play an important role in plant resistance and the quality of products from the plant. This study aims to reveal detailed changes in the populations of rhizosphere microorganisms, and providing theoretical guidance for the prevention and control of soil-borne diseases in A. lancea. A high-throughput sequencing approach was utilized to illustrate changes in the microbial community from different planting years. Results and conclusions: The results show that the diversity and composition of the root-associated microbiome was significantly impacted by the consecutive monoculture of A. lancea. At the level of the comparisons of the phyla, Bacteroidetes, Proteobacteria, Ascomycota, and Basidiomycota declined significantly. In contrast, the relative abundance of Actinobacteria, Acidobacteria, and Mortierellomycota distinctly increased. Comparisons at the genus level indicated that Sphingomonas, Flavobacterium, Pseudomonas, Pedobacter, and Tausonia decreased significantly, whereas Mortierella, Cylindrocarpon, Dactylonectria, and Mucor distinctly increased. In conclusion, this study helps to develop an understanding of the impediments involved in the consecutive monoculture of A. lancea.

SmbHLH53 is relevant to jasmonate signaling and plays dual roles in regulating the genes for enzymes in the pathway for salvianolic acid B biosynthesis in Salvia miltiorrhiza.

Basic helix-loop-helix (bHLH) transcription factors play essential roles in myriad regulatory processes, including secondary metabolism. In this study with Salvia miltiorrhiza, we isolated and characterized SmbHLH53, which encodes a bHLH family member. Expression of this gene was significantly induced by wounding and multiple hormones, including methyl jasmonic acid; transcript levels were highest in the leaves and roots. Phylogenetic analysis indicated that SmbHLH53 clusters withAtbHLH17 and AtbHLH13, two negative regulators of jasmonate (JA) responses, and is localized in the nucleus and cell membrane. Yeast two-hybrid and bimolecular fluorescent complementation assays indicated that SmbHLH53 forms a homodimer as well as a heterodimer with SmbHLH37. It also interacts with both SmJAZs1/3/8 and SmMYC2, the core members of the JA signal pathway. Unexpectedly, we noted that overexpression of SmbHLH53 did not significantly influence the concentrations of rosmarinic acid and salvianolic acid B in transgenic plants. Results from yeast one-hybrid assays showed that SmbHLH53 binds to the promoters of SmTAT1, SmPAL1, and Sm4CL9, the key genes for enzymes in the pathway for phenolic acid synthesis. Assays of transient transcriptional activity demonstrated that SmbHLH53 represses the promoter of SmTAT1 while activating the promoter of Sm4CL9. Thus, the present work revealed that SmbHLH53 may play dual roles in regulating the genes for enzymes in the pathway for Sal B biosynthesis.

Systematic analysis of SmWD40s, and responding of SmWD40-170 to drought stress by regulation of ABA- and H2O2-induced stomal movement in Salvia miltiorrhiza bunge.

WD40 proteins play crucial roles in response to abiotic stress. By screening the genome sequences of Salvia miltiorrhiza Bunge, 225 SmWD40 genes were identified and divided into 9 subfamilies (I-IX). Physiological, biochemical, gene structure, conserved protein motif and GO annotation analyses were performed on SmWD40 family members. The SmWD40-170 was found in 110 SmWD40 genes that contain drought response elements, SmWD40-170 was one of these genes whose response in terms of expression under drought was significant. The expression of SmWD40-170 was also up-regulated by ABA and H2O2. Through observed the stomatal phenotype of SmWD40-170 transgenic lines, the stomatal closure was abolished under dehydration, ABA and H2O2 treatment in SmWD40-170 knockdown lines. Abscisic acid (ABA), as the key phytohormone, elevates reactive oxygen species (ROS) levels under drought stress. The ABA-ROS interaction mediated the generation of H2O2 and the activation of anion channel in guard cells. The osmolality alteration of guard cells further accelerated the stomatal closure. As a second messenger, nitric oxide (NO) regulated ABA signaling, the NO stimulated protein kinase activity inhibited the K+ influx which result in stomatal closure. These NO-relevant events were essential for ABA-induced stomatal closure. The reduction of NO production was also observed in the guard cells of SmWD40-170 knockdown lines. The abolished of stomatal closure attributed to the SmWD40-170 deficiency induced the reduction of NO content. In general, the SmWD40-170 is a critical drought response gene in SmWD40 gene family and regulates ABA- and H2O2-induced stomatal movement by affecting the synthesis of NO.

The complete chloroplast genome sequence of Angelica Tsinlingensis (Apioideae).

Angelica tsinlingensis is endemic in Shaanxi province (China), and is used as Angelica sinensis in folk. Owing to important medicinal value, wild A. sinensis has been over-exploited and become quite rare in China during over 2000 years. Angelica sensu lato (s.l.; Apiaceae subfamily Apioideae) is a taxonomically complex and controversial group, and A. tsinlingensis is clearly different from members of the Angelica s.s. clade with the morphological and molecular results. The complete chloroplast DNA sequence of A. tsinlingensis (GenBank accession number: MF924726) was determined in our study. The size of chloroplast genome of A. tsinlingensis is 147,104 bp, including a large single-copy (LSC) region of 93376 bp and a small single-copy (SSC) region of 17,574 bp separated by a pair of identical inverted repeat regions (IRs) of 18,077 bp each. A total of 125 genes were successfully annotated containing 83 protein-coding genes, 34 tRNA genes and 8 rRNA genes. GC content of IRs region is the highest (44.5%). The result of Phylogenomic analysis supports the difference of A. tsinlingensis from Angelica s.s. clade.

[Characteristics of canopy stomatal conuctance in plantations of three re-vegetation tree species and its sensitivity to environmental factors].

In plantations of three different re-vegetation tree species (Schima superba, Acacia auriculaeformis and Eucalyptus citriodora) in southern China, the stem sap flow of individuals at different DBH classes were monitored using Granier's thermal dissipation probes. With synchronously-measured meteorological data, the canopy stomatal conductance (g(c)) was determined and the responses of g(c) to environmental variables were analyzed. We found that daytime mean g(c) in S. superba forest on average was significantly higher than those of A. auriculaeformis and E. citriodora plantations during a year (except in March). In the three plantations, g(c) was positively logarithmically correlated with photosynthetically active radiation (PAR) (P < 0.001), with a higher sensitivity of g(c) to PAR during wet season than that of dry season. By contrast, a negative logarithmical correlation between g(c) and vapor pressure deficit (VPD) was observed, with a higher sensitivity of g(c) to VPD during the wet season. Additionally, a higher partial correlation coefficient between g(c) and VPD was observed during wet season, indicating that VPD played a more important role in regulating the behavior of stomata during wet season. In general, the sensitivity of g(c) to VPD decreased with the decreases of soil water content, but more manifest decreases were found in S. superba and E. citriodora forests than in A. auriculaeformis plantation, while the descend degree in S. superba and E. citriodora forests were equal. Overall, our results demonstrated that the native species S. superba is more suitable for re-vegetation in southern China than the exotic species A. auriculaeformis and E. citriodora.

[Water use of re-vegetation pioneer tree species Schima superba and Acacia mangium in hilly land of South China].

The xylem sap flows of two pioneer tree species, i.e., Acacia mangium and Schima superba, in degraded hill lands of South China, were continually monitored with Granier' s thermal dissipation probes during 2004-2007 and 2008-2012, respectively, and their seasonal transpiration changes at different tree age levels were compared. The results showed that the annual transpiration of both species increased with tree ages, and S. superba demonstrated a higher value than A. mangium. The average annual whole-tree transpiration of S. superba (7014.76 kg) was higher than that of A. mangium (3704.97 kg). A. mangium (511.46-1802.17 kg) had greater seasonal variation than S. superba (1346.48-2349.35 kg). The standard regression coefficients (beta) of transpiration (Eh), photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) for both species increased with soil moisture, suggesting the increase of soil moisture generated a greater sensitivity of plants to environmental factors. Partial correlation analysis revealed that soil moisture played an important role in the seasonal variation of transpiration of both species. The optimum soil moistures of S. superba and A. mangium were 0.22-0.40 and 0.29-0.30 (V/V), respectively, indicating the native pioneer species S. superba better adapted to water deficit compared with exotic pioneer species A. mangium.

[Natural forming causes of China population distribution].

The diverse natural environment in China causes the spatial heterogeneity of China population distribution. It is essential to understand the interrelations between the population distribution pattern and natural environment to enhance the understanding of the man-land relationship and the realization of the sustainable management for the population, resources, and environment. This paper analyzed the China population distribution by adopting the index of population density (PD) in combining with spatial statistic method and Lorenz curve, and discussed the effects of the natural factors on the population distribution and the interrelations between the population distribution and 16 indices including average annual precipitation (AAP), average annual temperature (AAT), average annual sunshine duration (AASD), precipitation variation (PV), temperature variation (TV), sunshine duration variation (SDV), relative humidity (RH), aridity index (AI), warmth index ( WI), > or = 5 degrees C annual accumulated temperature (AACT), average elevation (AE), relative height difference (RHD), surface roughness (SR), water system density (WSD), net primary productivity (NPP), and shortest distance to seashore (SDTS). There existed an obvious aggregation phenomenon in the population distribution in China. The PD was high in east China, medium in central China, and low in west China, presenting an obvious positive spatial association. The PD was significantly positively correlated with WSD, AAT, AAP, NPP, AACT, PV, RH, and WI, and significantly negatively correlated with RHD, AE, SDV, SR, and SDTS. The climate factors (AAT, WI, PV, and NPP), topography factors (SR and RHD), and water system factor (WSD) together determined the basic pattern of the population distribution in China. It was suggested that the monitoring of the eco-environment in the east China of high population density should be strengthened to avoid the eco-environmental degradation due to the expanding population, and the conservation of the eco-environment in the central and west China with vulnerable eco-environment should also be strengthened to enhance the population carrying ability of these regions and to mitigate the eco-environmental pressure in the east China of high population density.

[Responses of Ilex integra Thunb. seedlings to elevated air ozone concentration].

One-year-old Ilex integra seedlings were exposed to charcoal-filtered (CF) and elevated ozone (E-O3, approximately 150 microL x L(-1)) for 84 days in six open-top chambers. Visible injury, growth parameters, pigments content, gas exchange, chlorophyll a fluorescence and antioxidant system were investigated during the growing season. At the end of experiment, foliage showed remarkable visible symptoms with dark-brown necrotic spots and patches which were concaved on the upper surface of the current-year leaves. Although relative height and diameter increment, total biomass and specific leaf weight (SLW) remained unaffected, E-O3 significantly decreased the percentage of stem biomass in total biomass. E-O3 induced significant decrease in net photosynthetic rate, chlorophyll a/b ratio and total phenolic compound content by 19%, 9% and 36%, respectively. However, stomatal conductance, intercellular CO2 concentration, chlorophyll a fluorescence parameters, pigment contents, MDA contents, total antioxidant capacity and total ascorbate content remained unaffected by E-O3. The results suggested that E-O3-induced change in components of chlorophyll contributed to the reduction of photosynthesis in Ilex integra seedlings. In addition, although visible symptom was found during the experiment, antioxidant system, most of the physiological parameters and growth were not significantly affected by E-O3.

Parameter uncertainty analysis of non-point source pollution from different land use types.

Land use type is one of the most important factors that affect the uncertainty in non-point source (NPS) pollution simulation. In this study, seventeen sensitive parameters were screened from the Soil and Water Assessment Tool (SWAT) model for parameter uncertainty analysis for different land use types in the Daning River Watershed of the Three Gorges Reservoir area, China. First-Order Error Analysis (FOEA) method was adopted to analyze the effect of parameter uncertainty on model outputs under three types of land use, namely, plantation, forest and grassland. The model outputs selected in this study consisted of runoff, sediment yield, organic nitrogen (N), and total phosphorus (TP). The results indicated that the uncertainty conferred by the parameters differed among the three land use types. In forest and grassland, the parameter uncertainty in NPS pollution was primarily associated with runoff processes, but in plantation, the main uncertain parameters were related to runoff process and soil properties. Taken together, the study suggested that adjusting the structure of land use and controlling fertilizer use are helpful methods to control the NPS pollution in the Daning River Watershed.

[Research on QSPR for n-octanol-water partition coefficients of organic compounds based on genetic algorithms-support vector machine and genetic algorithms-radial basis function neural networks].

A modified method to develop quantitative structure-property relationship (QSPR) models of organic compounds was proposed based on genetic algorithm (GA) and support vector machine (SVM) (GA-SVM). GA was used to perform the variable selection, and SVM was used to construct QSPR models. GA-SVM was applied to develop the QSPR models for n-octanol-water partition coefficients ( Kow) of 38 typical organic compounds in food industry. 5 descriptors (molecular weights, Hansen polarity, boiling point, percent oxygen and percent hydrogen) were selected in the QSPR model. The coefficient of multiple determination (R2), the sum of squares due to error (SSE) and the root mean squared error (RMSE) values between the measured values and predicted values of the model developed by GA-SVM are 0.999, 0.048 and 0.036, respectively, indicating good predictive capability for lgKow values of these organic compounds. Based on leave-one-out cross validation, the QSPR model constructed by GA-SVM showed good robustness (SSE = 0.295, RMSE = 0.089, R2 = 0.995). Moreover, the models developed by GA-SVM were compared with the models constructed by genetic algorithm-radial basis function neural network (GA-RBFNN) and linear method. The models constructed by GA-SVM show the optimal predictive capability and robustness in the comparison, which illustrates GA-SVM is the optimal method for developing QSPR models for lgKow values of these organic compounds.

[Study on the grain-size distribution of polycyclic aromatic hydrocarbons in Yangtze River sediment].

Sediments collected from Yangtze River were separated into five size fractions ( > 200 microm, 200 - 125 microm, 125 - 63 microm, 63 - 25 microm, <25 microm) by wet sieving. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) listed as U.S. EPA priority pollutants were determined in the fractionated sediments. Sigma PAHs concentrations ranged from 26.1 to 7135.9 ng/g and varied largely among the different size fractions. The highest Sigma PAHs concentration (7135.9 ng/g) was associated with the largest size fraction ( > 200 microm) while the fine silt fraction (63 - 25 microm) contained the lowest Sigma PAHs concentration, 26.1 ng/g. Although the PAHs concentrations difference among different fractions was great, the composition of PAHs in the five size fractions showed similar pattern dominated by PAHs with three or more rings. Sediment particles less than 25 microm contributed 75% of the Sigma PAHs, while comprising 38.6% of bulk sediment dry weight. A significant positive correlation (p < 0.01) between PAHs and total organic carbon (TOC) existing for all size fractions demonstrated that TOC was important for PAHs distribution in sediments. Additionally, sediment organic matter type and structure also played an important role in PAHs distribution in different grain size fractions.

[Research on quantitative structure-property relationships for n-octanol/water partition coefficients of phthalic acid esters].

Quantum chemical parameters based on the PM3 method were calculated for phthalic acid esters (PAEs). Using partial least squares (PLS) algorithm, a quantitative structure-property relationships (QSAR) model for the n-octanol/water partition coefficients (K(ow)) of PAEs was developed. The result indicates that the model has a good stability and predicting ability. It can be concluded from this study that the main factors affecting IgK(ow) of PAEs are total energy (TE), relative molecular weight (M(r)), average molecular polarizability (alpha) and standard heat of formation (deltaH(f)). The IgK(ow) values increase with increasing M(r) and a values. In contrast, increasing TE and deltaH(f) values leads to the decrease of IgK(ow).

[Prediction of photolysis half-lives of PCDD /Fs adsorbed on spruce needles optimized by genetic algorithm].

Adopting quantum chemical parameters of PCDD/Fs computed with quantum chemical PM3 algorithm, quantitative structure-property relationship (QSPR) model, which could predict photolysis half-life (t1/2) of PCDD/Fs adsorbed to spruce [Picea abies (L.) Karst.] needle surfaces, is established using genetic algorithm (GA) algorithm. It is considered that the main factors affecting lg t1/2 of PCDD/Fs are the energy of the highest occupied molecular orbital (EHOMO), ELUMO - EHOMO and average molecular polarizability (alpha). The lg t1/2 values increase with the increasing of EHOMO and a. The relationship between the lg t1/2 values and ELUMO - EHOMO is a parabolic curve. The lg t1/2 values increase with the increasing of ELUMO - EHOMO when ELUMO - EHOMO > or = 7.847 and decrease with the increasing of when ELUMO - EHOMO < or = 7.847.

[Chlorobenzenes in water and surface sediments from Tonghui River of Beijing].

Eleven chlorobenzenes (except MCB of a total of 12 in the congener series) in water and surface sediment samples collected from Tonghui River of Beijing China in November,2003 are analyzed. The range of total chlorobenzenes (CBs) was 0.093 - 6.638 microg x L(-1) in water, among which DCBs occupy 88.8%; while 95.3 - 1 827.7 ng x g(-1) in surface sediments, among which DCBs, TCBs,TeCBs,PeCB and HCB occupy 15.6%, 31.7%, 17.6%, 21.2% and 13.9% respectively. Comparison with the results of other research areas, the pollution of CBs in surface sediments is some serious. Besides, there is no significant correlation between total CBs concentrations in water and those in surface sediments.

[Influential factors on the toxicity of pentachlorophenol sodium with MICROTOX system in water].

The biological toxicity of pentachlorophenol sodium (Na-PCP), a typical kind of aquatic organic pollutants, was tested with the MICROTOX system using luminescent bacteria with the influence of several factors taken into consideration. The EC50 of Na-PCP increases with the increasing of the pH and hardness of the sample. The EC50 (15 min) of Na-PCP is approximately equal to its EC50 (20 min). Compared with some common organic pollutants, which exhibit little influence on the toxicity of Na-PCP when mixed, Na-PCP is more toxic. A reduction of 14% in relative luminescent rate was observed in the experiment with a natural sample. The natural sample exhibits similar influence on the toxicity of Na-PCP similarly compared with unionized water.