摘要：
Lignocellulose is the most abundant biomass on earth. However, biomass recalcitrance has become a major factor affecting biofuel production. Although cellulose crystallinity significantly influences biomass saccharification, little is known about the impact of three major wall polymers on cellulose crystallization. In this study, we selected six typical pairs of Miscanthus samples that presented different cell wall compositions, and then compared their cellulose crystallinity and biomass digestibility after various chemical pretreatments. A Miscanthus sample with a high hemicelluloses level was determined to have a relatively low cellulose crystallinity index (CrI) and enhanced biomass digestibility at similar rates after pretreatments of NaOH and H2SO4 with three concentrations. By contrast, a Miscanthus sample with a high cellulose or lignin level showed increased CrI and low biomass saccharification, particularly after H2SO4 pretreatment. Correlation analysis revealed that the cellulose CrI negatively affected biomass digestion. Increased hemicelluloses level by 25% or decreased cellulose and lignin contents by 31% and 37% were also found to result in increased hexose yields by 1.3-times to 2.2-times released from enzymatic hydrolysis after NaOH or H2SO4 pretreatments. The findings indicated that hemicelluloses were the dominant and positive factor, whereas cellulose and lignin had synergistic and negative effects on biomass digestibility. Using six pairs of Miscanthus samples with different cell wall compositions, hemicelluloses were revealed to be the dominant factor that positively determined biomass digestibility after pretreatments with NaOH or H2SO4 by negatively affecting cellulose crystallinity. The results suggested potential approaches to the genetic modifications of bioenergy crops.
摘要：
Although photocatalytic degradation is an ideal strategy for cleaning environmental pollution, it remains challenging to construct a highly efficient photocatalytic system by steering the charge flow in a precise manner. In this study, a novel atomic scale g-C3N4/Bi2WO6 heterojunction (UTCB) constructed by ultrathin g-C3N4 nanosheets (ug-CN) and monolayer Bi2WO6 nanosheets (m-BWO) was successfully prepared by hydrothermal reaction. The UTCB heterojunctions were characterized by various techniques including XRD, TEM, AFM, BET measurements, UV–vis spectrometry, and XPS. The results indicated that UTCB heterojunctions were assembly of m-BWO on ug-CN and presented high separation efficiency of photogenerated carriers. Under visible light irradiation, the optimum molar ratio of ug-CN/m-BWO (1:4, UTCB-25) reached almost 96.1% removal efficiency of IBF within 1 h, which was about 2.7 times as that of pure m-BWO. The photocatalytic mechanisms of UTCB-25 were revealed, suggesting that the synergistic effect of UTCB-25 heterojunction with strong interfacial interaction promoted the photoinduced charge separation. According to the LC–MS/MS, five photodegradation pathways of IBF under visible light irradiation were proposed. This study could open new opportunities for the rational design and a better understanding of atomic scale two dimensions/two dimensions (2D/2D) heterojunctions in environmental or other applications.
摘要：
Cucurbitacins are triterpenoids that confer a bitter taste in cucurbits such as cucumber, melon, watermelon, squash, and pumpkin. These compounds discourage most pests on the plant and have also been shown to have antitumor properties. With genomics and biochemistry, we identified nine cucumber genes in the pathway for biosynthesis of cucurbitacin C and elucidated four catalytic steps. We discovered transcription factors Bl (Bitter leaf) and Bt (Bitter fruit) that regulate this pathway in leaves and fruits, respectively. Traces in genomic signatures indicated that selection imposed on Bt during domestication led to derivation of nonbitter cucurbits from their bitter ancestors.
摘要：
The goal of this study was to identify and prioritize some of the physico-chemical parameters that contributed to bacterial and fungal community compositions during agricultural waste composting. Relationships between those parameters and microbial community compositions determined by PCR-DGGE were simultaneously evaluated by redundancy analysis (RDA). The results showed that the temporal variation of bacterial community composition was significantly related to water soluble carbon (WSC), ammonium and nitrate (P < 0.05), while the most variation in distribution of fungal community composition was statistically explained by pile temperature, WSC, and moisture content (P < 0.05). Significant amounts of the variation (54.9% and 56.0% for bacterial and fungal species data, respectively) were explained by those parameters, suggesting that those parameters were the most likely ones to influence, or be influenced by the bacterial and fungal species. Variation partitioning analyses indicated that WSC and pile temperature showed predominant effect on the bacterial and fungal community composition, respectively. (C) 2010 Elsevier Ltd. All rights reserved.
摘要：
AP2/ERF proteins play crucial roles in various biological processes. RAP2.6, an Arabidopsis AP2/ERF family member, has been reported to function in plant response to biotic stress, but whether it also functions in plant response to abiotic stress is not known. In this work, we demonstrate that in wild-type Arabidopsis, the expression of RAP2.6 is responsive to abscisic acid (ABA) and different stress conditions such as high salt, osmotic stress, and cold. Trans-activating ability tests in yeast demonstrate that RAP2.6 could act as a transactivator. RAP2.6 is able to bind to the GCC and CE1 cis-elements, as confirmed by both electrophoretic mobility shift assay (EMSA) and yeast one-hybrid assay. Experiments with RAP2.6-YFP fusion protein indicated that RAP2.6 is nuclear localized. Overexpression of RAP2.6 conferred hypersensitivity to exogenous ABA and abiotic stresses during seed germination and early seedling growth in Arabidopsis. The ABA content in RAP2.6 overexpressor lines decreased after being treated with salt. Furthermore, transcripts of AtABI4 and some stress inducible genes increased, and loss of ABI4 function rescues the hypersensitive phenotype of RAP2.6 overexpression lines under ABA and stress treatment. These results suggest that RAP2.6 participates in abiotic stress, possibly through the ABA-dependent pathway.
作者：
Xu, W.;Luo, X. S.;Pan, Y. P.;Zhang, L.;Tang, A. H.;Shen, J. L.;Zhang, Y.;Li, K. H.;Wu, Q. H.;Yang, D. W.;Zhang, Y. Y.;Xue, J.;Li, W. Q.;Li, Q. Q.;Tang, L.;Lu, S. H.;Liang, T.;Tong, Y. A.;Liu, P.;Zhang, Q.
期刊：
ATMOSPHERIC CHEMISTRY AND PHYSICS,2015年15(21):12345-12360 ISSN：1680-7316
通讯作者：
Liu, X. J.
作者机构：
[Wu, Q. H.; Zhang, Y. Y.; Liu, X. J.; Xu, W.; Tang, A. H.; Li, Q. Q.; Yang, D. W.; Xue, J.; Luo, X. S.; Zhang, F. S.] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.;[Luo, X. S.] Henan Acad Agr Sci, Inst Plant Nutr Resources & Environm Sci, Zhengzhou 450002, Peoples R China.;[Pan, Y. P.] Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China.;[Zhang, L.] Peking Univ, Sch Phys, Dept Atmospher & Ocean Sci, Lab Climate & Ocean Atmosphere Studies, Beijing 100871, Peoples R China.;[Shen, J. L.] Chinese Acad Sci, Inst Subtrop Agr, Changsha 4410125, Hunan, Peoples R China.
通讯机构：
[Liu, X. J.] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.
摘要：
A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3- in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of N-r species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric N-r concentrations and dry and wet/bulk N-r deposition. On a national basis, the annual average concentrations (1.3-47.0 mu g N m(-3)) and dry plus wet/bulk deposition fluxes (2.9-83.3 kg N ha(-1) yr(-1)) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic N-r emission. Average dry and wet/bulk N deposition fluxes were 20.6 +/- 11.2 (mean +/- standard deviation) and 19.3 +/- 9.2 kg N ha(-1) yr(-1) across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.
摘要：
Highly efficient simultaneous removal of Cu(II) and tetracycline (TET) from aqueous solution was accomplished by iron and zinc doped sawdust biochar (Fe/Zn-biochar). The mutual effects and inner mechanisms of their adsorption onto Fe/Zn-biochar were systematically investigated via sole and binary systems, sorption isotherm and adsorption kinetics models. The liquid-film diffusion step might be the rate-limiting step for tetracycline, the interaction of Cu(II) was more likely controlled by both intra particle diffusion model and liquid film diffusion model. The fitting of experimental data with kinetic models, Temkin model indicates that the adsorption process of tetracycline and Cu(II) involve chemisorption, and physico-chemical adsorption, respectively. There exists site competition and enhancement of Cu(II) and tetracycline on the sorption to Fe/Zn-biochar. The results of this study indicate that modification of biochar derived from sawdust shows great potential for simultaneous removal of Cu(II) and tetracycline from co-contaminated water.
摘要：
Miscanthus is a leading bioenergy candidate for biofuels, and it thus becomes essential to characterize the desire natural Miscanthus germplasm accessions with high biomass saccharification. In this study, total 171 natural Miscanthus accessions were geographically mapped using public database. According to the equation [P(H/L| East) = P(H/L∩East)/P(East)], the probability (P) parameters were calculated on relationships between geographical distributions of Miscanthus accessions in the East of China, and related factors with high(H) or low(L) values including biomass saccahrification under 1% NaOH and 1% H2SO4 pretreatments, lignocellulose features and climate conditions. Based on the maximum P value, a golden cutting line was generated from 42°25’ N, 108°22’ E to 22°58’ N, 116°28’ E on the original locations of Miscanthus accessions with high P(H|East) values (0.800–0.813), indicating that more than 90% Miscanthus accessions were originally located in the East with high biomass saccharification. Furthermore, the averaged insolation showed high P (H|East) and P(East|H) values at 0.782 and 0.754, whereas other climate factors had low P(East|H) values, suggesting that the averaged insolation is unique factor on Miscanthus distributions for biomass saccharification. In terms of cell wall compositions and wall polymer features, both hemicelluloses level and cellulose crystallinity (CrI) of Miscanthus accessions exhibited relative high P values, suggesting that they should be the major factors accounting for geographic distributions of Miscanthus accessions with high biomass digestibility.
摘要：
Globalization has provided opportunities for parasites/pathogens to cross geographic boundaries and expand to new hosts. Recent studies showed that Nosema ceranae, originally considered a microsporidian parasite of Eastern honey bees, Apis cerana, is a disease agent of nosemosis in European honey bees, Apis mellifera, along with the resident species, Nosema apis. Further studies indicated that disease caused by N. ceranae in European honey bees is far more prevalent than that caused by N. apis. In order to gain more insight into the epidemiology of Nosema parasitism in honey bees, we conducted studies to investigate infection of Nosema in its original host, Eastern honey bees, using conventional PCR and duplex real time quantitative PCR methods. Our results showed that A. cerana was infected not only with N. ceranae as previously reported [Fries, I., Feng, F., Silva, A.D., Slemenda, S.B., Pieniazek, N.J., 1996. Nosema ceranae n. sp. (Microspora, Nosematidae), morphological and molecular characterization of a microsporidian parasite of the Asian honey bee Apis cerana (Hymenoptera, Apidae). Eur. J. Protistol. 32, 356–365], but also with N. apis. Both microsporidia produced single and mixed infections. Overall and at each location alone, the prevalence of N. ceranae was higher than that of N. apis. In all cases of mixed infections, the number of N. ceranae gene copies (corresponding to the parasite load) significantly out numbered those of N. apis. Phylogenetic analysis based on a variable region of small subunit ribosomal RNA (SSUrRNA) showed four distinct clades of N. apis and five clades of N. ceranae and that geographical distance does not appear to influence the genetic diversity of Nosema populations. The results from this study demonstrated that duplex real-time qPCR assay developed in this study is a valuable tool for quantitative measurement of Nosema and can be used to monitor the progression of microsprodian infections of honey bees in a timely and cost efficient manner.
摘要：
Rice feeds more than half of the world's population. Rice blast, caused by the fungal pathogen , and bacterial blight, caused by the bacterial pathogen pv. , are major constraints to rice production worldwide. Genome sequencing and extensive molecular analysis has led to the identification of many new pathogen-associated molecular patterns (PAMPs) and avirulence and virulence effectors in both pathogens, as well as effector targets and receptors in the rice host. Characterization of these effectors, host targets, and resistance genes has provided new insight into innate immunity in plants. Some of the new findings, such as the binding activity of transcriptional activator–like (TAL) effectors to specific rice genomic sequences, are being used for the development of effective disease control methods and genome modification tools. This review summarizes the recent progress toward understanding the recognition and signaling events that govern rice innate immunity.
摘要：
Humic acid-coated Fe3O4 (HA-Fe3O4) nanoparticles as magnetic adsorbents were prepared with co-precipitation of humic acids and Fe3O4 nanoparticles. TEM analysis indicated that the average diameter of the spherical HA-Fe3O4 core was about 15 nm. TGA characterization showed that the HA-Fe3O4 nanoparticles contained about 50% (w/w) HA. The characteristic absorption of HA at 1604/cm and 1701/cm was observed in the FIRT spectra of HA-Fe3O4 nanoparticles. The HA-Fe3O4 nanoparticles exhibited a typical superparamagnetic characteristic with a saturation magnetization of 77 emu/g, which resulted in an easy solid–liquid separation with an external magnet. The HA-Fe3O4 nanoparticles were applied for methylene blue (MB) adsorption and results showed that the HA-Fe3O4 nanoparticles possessed much higher adsorbed amount of MB than the bare Fe3O4 nanoparticles and HA powders. The HA-Fe3O4 nanoparticles remained stable in a broad pH range of 3–11. The adsorption kinetics can be described by a pseudo-second-order equation, and the time when 50% of the MB was adsorbed (t1/2) was 7 min. The adsorption isotherm of the HA-Fe3O4 nanoparticles agreed well with Langmuir adsorption equation, and the maximum adsorbed amount of MB was 0.291 mmol/g. Desorption of the saturated HA-Fe3O4 nanoparticles was easily carried out with a mixture of methanol and acetic acid with a volume ratio of 9:1.
作者：
Rang, Z. W.;Jagadish, S. V. K.*;Zhou, Q. M.;Craufurd, P. Q.;Heuer, S.
期刊：
Environmental and Experimental Botany,2011年70(1):58-65 ISSN：0098-8472
通讯作者：
Jagadish, S. V. K.
作者机构：
[Heuer, S.; Jagadish, S. V. K.; Rang, Z. W.] Int Rice Res Inst, Manila, Philippines.;[Zhou, Q. M.; Rang, Z. W.] Hunan Agr Univ, Coll Agron, Changsha 410128, Hunan, Peoples R China.;[Craufurd, P. Q.] Int Crops Res Inst Semi Arid Trop, Patancheru 502324, Andhra Pradesh, India.;[Jagadish, S. V. K.] Int Rice Res Inst, DAPO Box 7777, Manila, Philippines.
通讯机构：
[Jagadish, S. V. K.] Int Rice Res Inst, DAPO Box 7777, Manila, Philippines.
摘要：
In future climates, rice could more frequently be subjected to simultaneous high temperature and water stress during sensitive developmental stages such as flowering. In this study, five rice genotypes were exposed to high temperature, water stress and combined high temperature and water stress during flowering to quantify their response through spikelet fertility. Microscopic analyses revealed significant differences in anther dehiscence between treatments and genotypes, with a moderately high association with the number of germinated pollen grains on the stigma. There was a strong relationship between spikelet fertility and the number of germinated pollen on stigmas. Although, all three stress treatments resulted in spikelet sterility, high-temperature stress caused the highest sterility in all five genotypes. A cumulative linear decline in spikelet fertility with increasing duration of independent high-temperature stress and in combination with water stress was quantified. Better anther dehiscence, higher in vivo pollen germination, and higher spikelet fertility were observed in both the N22 accessions compared with IR64, Apo and Moroberekan under high temperature, water stress and combined stress, indicating its ability to tolerate multiple abiotic stresses. (C) 2010 Elsevier B.V. All rights reserved.
摘要：
Anhedonia is a hallmark symptom of major depressive disorder (MDD). Preliminary findings suggest that anhedonia is characterized by reduced reward anticipation and motivation of obtaining reward. However, relatively little is known about reward-based decision-making in depression. We tested the hypothesis that anhedonia in MDD may reflect specific impairments in motivation on reward-based decision-making and the deficits might be associated with depressive symptoms severity. In study 1, individuals with and without depressive symptoms performed the modified version of the Effort Expenditure for Rewards Task (EEfRT), a behavioral measure of cost/benefit decision-making. In study 2, MDD patients, remitted MDD patients and healthy controls were recruited for the same procedures. We found evidence for decreased willingness to make effort for rewards among individuals with subsyndromal depression; the effect was amplified in MDD patients, but dissipated in patients with remitted depression. We also found that reduced anticipatory and consummatory pleasure predicted decreased willingness to expend efforts to obtain rewards in MDD patients. For individuals with subsyndromal depression, the impairments were correlated with anticipatory anhedonia but not consummatory anhedonia. These data offer novel evidence that motivational deficits in MDD are correlated with depression severity and predicted by self-reported anhedonia. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
