- Li Mo;Pan Xiao-cheng;Liu Yang;Li Yuan-ming;Li Hong-wei;Liu Wei;Su An-yu;Wu Xiao-xia;
ENHANCER OF SHOOT REGENERATION (ESR1) is an important regulator of plant regeneration in vitro,which promotes regeneration of plant.In this study,transgenic positive plants with normal expression of proteins were screened by molecular assay.Through the study of the transgenic plants and the control Dongnong 50,the difference between immature embryo-induced callus and induced shoot bud was observed.The increase in callus weight indicated that GmESR1 gene accelerated the formations of shoot buds.By measuring the changes of hormone in the process of induction callus of transgenic plants,it was found that the contents of indole-3-acetic acid (IAA) and zeatin (ZT) in transgenic lines were significantly increased.It could be concluded that GmESR1 gene promoted the accumulation of hormone and affected regeneration process.In addition,this study also verified the interaction between GmBIM1 gene and GmESR1 gene by bimolecular fluorescence complementation (BiFC).
2020年02期 v.27;No.79 1-8页 [查看摘要][在线阅读][下载 687K] [下载次数：23 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：14 ] - Gu Jiao-jiao;Zhao Hong-wei;Jia Yan;Hu Bo-wen;Wang Zhuo-qian;Qu Zhao-jun;Yu Feng-li;
The aims were to investigate the effect of salt stress on key enzyme activity of nitrogen metabolism and the concentration of nitrate nitrogen and ammonium nitrogen response to salt stress.Two rice cultivars,Mudanjiang 30 (sensitive cultivar) and Longdao 5 (salt-tolerant cultivar),were treated with different salt concentrations (CK 0%,S1 0.075%,S2 0.15%,S3 0.225% and S4 0.3%).The results showed that the activities of nitrate reductase (NR),glutamine synthase (GS),glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) in the functional leaves and roots of rice in cold region presented a single peak curve change and the peak occurred in the heading stage;compared with those of the CK,the activities of NR,GS and GOGAT of rice in cold region decreased,but the activity of GDH increased in the heading stage under salt stress.The variation for key enzyme activity of nitrogen metabolism was the highest under S4 treatment.The activities of NR,GS and GOGAT in the functional leaves significantly decreased compared with those in roots;the concentrations of nitrate nitrogen and ammonium nitrogen in the functional leaves and roots of rice in cold region presented a single peak curve change and the peak occurred in the heading stage;compared with that of the CK,the concentration of nitrate nitrogen decreased in leaves and roots,the concentration of ammonium nitrogen decreased and the concentration of ammonium nitrogen in roots increased under salt stress.The variations for the activities of NR,GS and GOGAT in the functional leaves and roots of Longdao 5 were less than those of Mudanjiang 30 under the same concentration of salt stress.
2020年02期 v.27;No.79 9-16页 [查看摘要][在线阅读][下载 362K] [下载次数：15 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：8 ] - Dai Jian-jun;Zhang Yu-fei;Wang Xiao-chun;Ma Yu-xuan;Liu Li-zhi;
To explore the effects of farming methods,straw returning and their interaction on corn yield and nitrogen utilization,the experiment was conducted for two consecutive years from 2016 to 2017 at the Xiangyang Experimental Base of Northeast Agricultural University in Heilongjiang Province of China.The method of combining farming with straw returning was used and six treatments as rotary tillage (R)+no straw returning (K),rotary tillage (R)+straw returning (S),tillage (T)+no straw returning (K),tillage (T)+straw returning (S),tillage (T)+subsoiling (D)+no straw returning (K) and tillage (T)+subsoiling (D)+straw returning (S) were set to study the effects of different tillage methods and straw returning on corn yield and nitrogen accumulation and utilization.The corn yield,nitrogen accumulation,nitrogen transport,grain weight and dry matter accumulation of tillage (T)+subsoiling (D) and tillage (T) were significantly higher than those of rotary tillage (R) treatment.Meanwhile,the corn yield,nitrogen accumulation and dry matter accumulation of TD treatment were significantly higher than those of T treatment;the corn yield,dry matter accumulation,kernel weight,nitrogen dry matter production efficiency and nitrogen grain production efficiency of S treatment were significantly higher than those of K treatment.Among the treatments,the yield,nitrogen accumulation and utilization efficiency of TDS,TS and TDK were the highest.The yield,nitrogen accumulation and nitrogen transport of TDS were significantly higher than those of TS.In 2016,TDS production increased by 7.30% and 8.20% compared with TS;and TDS nitrogen accumulation increased by 6.78% and 9.50% compared with TS,while the yield and nitrogen grain production efficiency were significantly higher than those of TDK.Therefore,under the conditions of this experiment,on the basis of straw returning,tillage+subsoiling was the suitable farming method.
2020年02期 v.27;No.79 17-24页 [查看摘要][在线阅读][下载 368K] [下载次数：13 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：10 ] - Ren Hong-yu;Miao Yan-li;Wang Zhen-hua;Zhuang Zhong;Li Xin;Zhang Xing-wen;
Rare earth has a long history of agricultural use and can improve the yield and quality of agricultural by-products,but its regulation mechanism is still unclear.The aim of the study was to investigate the effects of lanthanum and cerium on the activities of peroxidase,catalase and ascorbate peroxidase in leaves of soybeans [Glycine max (L.) Merr].Soybean varieties of Dongnong 42,Dongnong 47 and Dongnong 52 from Northeast China were used as experimental materials.The samples were tested by spraying different concentrations of LaCl_3 (120,150 and 180 mg·L~(-1)),CeCl_3 (30,60 and 90 mg·L~(-1)) and LaCl_3+CeCl_3 (30,40 and60 mg·L~(-1 )mix) solutions on the leaves at the seedling stage and the early flowering stage of soybeans.The results showed that the suitable species and concentrations of lanthanum and cerium could increased the activities of antioxidant enzymes in soybean leaves,but the effects of lanthanum and cerium on different varieties of soybeans were also different.For Dongnong 42,the optimum lanthanum and cerium treatment was 60 mg·L~(-1) LaCl_3+CeCl_3,and the activities of peroxidase,catalase and ascorbate peroxidase increased by 11.36% (p<0.05),13.89% (p>0.05) and 50.00% (p<0.05) compared with those of CK.The optimal lanthanum and cerium treatment of Dongnong 47 was40 mg·L~(-1) LaCl_3+CeCl_3.Compared with those of CK,the above three enzyme activities increased by 15.80% (p<0.05),51.52% (p<0.05) and 20.75% (p>0.05).The optimal lanthanum and cerium treatment of Dongnong 52 was 60 mg·L~(-1) LaCl_3+CeCl_3,which increased the activities of the three enzymes by 33.49% (p<0.05),19.23% (p>0.05) and 23.53% (p<0.05) compared with those of CK.
2020年02期 v.27;No.79 25-32页 [查看摘要][在线阅读][下载 374K] [下载次数：6 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：9 ] - Sun Yan-kun;Wang Zhen-hua;Li Xue-cong;Zhang Xing-wen;Ren Hong-yu;Jing Yu;
In order to explore the effects of different silicon preparations on the soil fertility of paddy fields,a pot experiment with Dongnong 427 was carried on.Different types of silicon preparations,including Si-50-G,Si-60-G,Si-RH,Si-50 and Si-60,were sprayed on the leaves of rice at the tillering stage,and CK was set in the control stage.The contents of alkali nitrogen,available phosphorus,available potassium and available silicon in soil were determined in the tillering stage,booting stage and maturity stage of rice.The results showed that spraying different silicon preparations at the tillering stage could promote the activation and release of soil available nutrients in different degrees.
2020年02期 v.27;No.79 33-36页 [查看摘要][在线阅读][下载 1798K] [下载次数：6 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：7 ] - Sun Tao;Liu Xiao-jie;Paul Yeung;Xu Jing-gang;
Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils to estimate the uptake of organic and inorganic contaminants by plants from the oil contaminated soils.The experiment showed that the concentrations of some selected elements,such as B,Co and Ni in plants growing in the oil contaminated soils were significantly higher than those in plants growing in the uncontaminated control soil.The accumulation of metals in plants increased with plant biomass;however,the removal of metals by plants from the oil contaminated soils was not practical.
2020年02期 v.27;No.79 37-41页 [查看摘要][在线阅读][下载 379K] [下载次数：3 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：7 ] - Li De-shan;Jiang Shan;Liu Yun-ye;Rasoul Lubna;He Jin-jiao;Mir Hassan Khoso;Cao Hong-xue;Yang Jia-rui;Yin He;Yin Jie-chao;
Recombinant Newcastle disease virus (rNDV) has shown an anti-cancer effect in preclinical studies,but has never been tested for lung cancer models.This study explored the anti-cancer activity of genetically modified NDV expressing IL-2 (rNDV–IL-2) in lung cancer models.This study used Lewis lung carcinoma cell line (LLC) to create tumor models in C57 female mice,the tumor-bearing mice were treated with rNDV-IL-2,rNDV and phosphate-buffered saline (PBS),respectively.In vitro results revealed that rNDV effectively infected malignant cells and expressed IL-2,in vivo results revealed that rNDV expressing IL-2 was highly efficient in inhibiting lung cancer tumors,with an average tumor size of 291.255 mm~3 in rNDV-IL-2 group compared to 763.068 mm~3 in rNDV group and 1 101.68 mm~3 in PBS group.For the survival studies,treatment with rNDV-IL-2 enhanced the survival rates of tumor-bearing mice by 36% compared to those of rNDV treated mice and by 80% compared to those of vehicle-treated mice (survival rate:12 out of 15 for rNDV-IL-2 group;seven out of 15 for rNDV group and zero out of 15 for vehicle group).These results demonstrated that rNDV-expressed IL-2 enhanced the intrinsic anti-tumor ability of Newcastle disease virus in lung cancer models by further restrain of lung tumor growth and improvement of the survival rates of the tumor-bearing mice.The genetically modified rNDV-IL-2 was a good candidate for lung cancer therapy.
2020年02期 v.27;No.79 42-50页 [查看摘要][在线阅读][下载 796K] [下载次数：5 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：3 ] - Cui Yun-feng;Xing Yuan-yuan;Ren Jie;Yu Hao-nan;Ni Hua;
Lipopolysaccharide-binding protein (LBP) functions as an acute phase protein and plays a role in the innate immune response to bacterial challenge.To investigate the uterine expression of LBP during peri-implantation in mice,in situ hybridization and immunohistochemical staining were used to detect the mRNA and protein expression of LBP in mouse uteri in the early pregnancy,pseudopregnancy,artificial decidualization and hormone-treated mice.The results showed that LBP was expressed in uterine luminal epithelium (LE) and glandular epithelium (GE) during days 1-4 of pregnancy.During days 5-8,LBP was weakly expressed in the decidual cells around the embryo on the 5th day of pregnancy (implantation occurred),then gradually increased,LBP was strongly expressed in the decidual zone on the 8th day of pregnancy.The expression of LBP in pseudopregnancy was similar with pregnancy on days 1-4.In artificial decidualization mice,LBP was observed in uterine LE and GE in the control horn,whereas LBP expression was significantly higher in decidua of mouse uteri under artificial decidualization.In hormone-treated mice,the expression of LBP wasup-regulated by 17β-estradiol (E_2) and progesterone (P_4).In addition,the cultured mouse endometrial stromal cells (mESCs) were induced for in vitro decidualization with 10 nmol·L~(-1) E_2 and 1 μmol·L~(-1) P_4.Real-time PCR results showed that LBP mRNA expression was highly induced in mESCs after decidual stimulus.In vivo and in vitro experiments showed that LBP was expressed in the decidual cells,indicating that LBP involved in decidualization of mouse uteri.
2020年02期 v.27;No.79 51-58页 [查看摘要][在线阅读][下载 5635K] [下载次数：10 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：2 ] - Wang Wei-hua;Zhang Yan-ying;Huang Guan;Zhang Na;
The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,metabolomic methods based on ultra performance liquid chromatography-mass spectrometry (LC-MS) were used to study the liver metabolites of dairy cows fed on corn straw diet or mixed diet.Ten healthy Chinese Holstein cows were randomly assigned to two groups,under the same management condition,fed different diets respectively,corn straw group (CS) or a mixture of alfalfa hay and Chinese wild rye hay mixed forage group (MF).All the cows were fed for 8 weeks and recorded body weight,dry matter intake,body condition score,fat,protein,lactose,milk yield and the total solids.Livers were sampled from each cow through a liver puncture needle for analysis of a significant difference in small molecule metabolites in cow liver samples from the two different diets.The results suggested that different diet types had significant effects on liver metabolism and milk components in dairy cows.The contents of milk fat,the total solids,milk protein,lactose,dry matter intake (DMI),milk yield,milk protein (%),lactose (%) and milk fat (%) of the corn straw group were significantly lower than those of the mixed forage group (p<0.05);the contents of phosphatidylcholine (PC),histidine,hypoxanthine and mridine in liver tissues of the corn straw group were significantly lower than those in the mixed forage group (p<0.05);acetylcarnitine,uric acid,triacylglycerol (TG),acetal phosphatidylcholine (plasmenyl-PC),acetalphosphatidylethanolamine (plasmenyl-PE) and sphingomyelin (SM) of the corn straw group were significantly higher than those in the mixed forage group (p<0.05).In summary,cows fed on mixed forage diet significantly improved milk yield and lactation performance clearly.
2020年02期 v.27;No.79 59-66页 [查看摘要][在线阅读][下载 899K] [下载次数：0 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：4 ] - Wang Hui;Liu Qing-ju;Han Ping;
Douchi is a kind of traditional Chinese fermented soybean food.Ultra-high performance liquid chromatography quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS) was applied to separate and identify 12 kinds of isoflavones in Douchi within 16 min.The chromatographic separation was carried out on an ACQUITY UPLC HSS T3 column with a gradient elution program where water containing 0.1% formic acid and acetonitrile containing 0.1% formic acid were used as mobile phases.Detection by using electrospray ionization of positive ion mode was applied in the mass spectrometry.Isoflavones were identified by determining the accurate mass and referring to references in this study.
2020年02期 v.27;No.79 67-72页 [查看摘要][在线阅读][下载 474K] [下载次数：5 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：2 ] - Sun Rui-tao;Liu Da-sen;Zhang Mei-mei;Babarinde Emmanuel;Liu Hua-wei;Zhang Peng;Shi Ru-bin;
Micro-X-ray fluorescence (μ-XRF) and micro-X-ray absorption near edge structure (μ-XANES) have not been widely used in animal nutrition.In situ determination of iron distribution and oxidation state in broiler duodenal wall was done by μ-XRF and μ-XANES techniques.Fifty newly hatched healthy (1-day-old) Arbor Acres commercial male broilers were used in this experiment.The chicks were fed a corn-soybean meal basal diet (96.00 mg of Fe/kg diet) from the 1st day to the 21st day,but were fed a semi-purified diet (12.50 mg of Fe/kg diet) after 21 days to deplete the body Fe stores.On the 28th day,after an overnight fast,all the birds were randomly allotted to four different Fe sources [FeSO_4,Fe-Gly (II),FeCl_3 and Fe-Gly (Ⅲ)].Three points five mL nutrient solution was injected to a broiler's duodenum by technology of in situ ligated intestinal loops and a perfusion group without Fe sources added to the media was designed to exclude the effect of endogenous Fe.Being incubated for 30 min,duodenal midpieces sections were collected for analyses by μ-XRF and μ-XANES techniques.It was found that Fe concentration for ferrous Fe sources [FeSO_4 and Fe-Gly (Ⅱ)] was significantly higher than that for ferric Fe sources [FeCl_3 and Fe-Gly (Ⅲ)] in the duodenal wall,moreover,Fe-Gly (Ⅱ) group samples had the largest amount of Fe.μ-XANES spectra of Fe for the four sources were basically the same in the duodenal wall,which indicated that despite the ferric iron supplied to duodenum,ferrous iron could also be absorbed into the duodenal wall.
2020年02期 v.27;No.79 73-80页 [查看摘要][在线阅读][下载 1049K] [下载次数：4 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：6 ] - Liu Jian;Wang Qian-nan;Guo Xin;Duo Tian-qi;Li Ran;Hu Guo-fu;Zhang Xun-zhong;
Switchgrass (Panicum virgatum L.) as a high-quality bioenergy crop that can effectively improve saline-alkali soil has strong resistance to stress and grows well in marginal soil and some abiotic stress environments.This study used alkali-sensitive genotype AM (AM-314/MS-155) and alkali-tolerant genotype ALA (Alamo) as experimental materials to investigate molecular mechanisms of switchgrass tolerance to alkali-salt stress.When the plants were grown to E5 stage,the alkali-salt stress treatment was carried out by soaking method (Na_2CO_3:NaHCO_3=1:9,C_((Na+))=150 mmol·L~(-1) and pH=9.0) and fresh root samples were taken after treatments for 0 (CK),6 and 24 h,respectively,the differentially expressed microRNAs and their regulatory network were analyzed.A total of 1 049 known miRNAs and 68 novel miRNAs were identified.Seventy-two differentially expressed miRNAs in ALA were more than three times higher than those in AM and 36.1% differentially expressed miRNAs was significantly down-regulated (p<0.05).Through analyses of differentially expressed miRNAs and their target genes,it was found that under alkali-salt stress,differentially expressed miRNAs in AM were mainly involved in the regulation of cellular ROS clearance,ethylene signal transduction,and root,leaf and flower development.MiRNAs in ALA were also involved in water transport,DNA methylation,response to high osmotic pressure,activation of stress-related genes and more complex responses to alkali-salt stress processes,but those in AM were not.ALA was significantly higher than AM in the number of microRNAs responding to alkali-salt stress and in the functional diversity of their regulatory target genes.
2020年02期 v.27;No.79 81-89页 [查看摘要][在线阅读][下载 639K] [下载次数：1 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：3 ] - Yang Yao;Xu Li-ming;Zhao Jing-zhuang;Ren Guang-ming;Lu Tong-yan;Yin Hai-fu;
The purpose of this study was to establish a method for the rapid detection of infectious pancreatic necrosis virus (IPNV,Jasper serotype) using reverse transcription loop-mediated isothermal amplification (RT-LAMP).Four groups of specific primers were designed,according to the genome sequence of a Chinese IPNV isolate ChRtm213.The results showed that primer set B2 had the best amplification effect.When the final concentration of Mg~(2+) was 6 mmol·L~(-1),dNTPs were 1 mmol·L~(-1) and betaine was 0.4 mol·L~(-1),the reaction could be completed in a 63℃ water bath within 60 min.This RT-LAMP assay for the detection of IPNV had no cross-reactivity with infectious hematopoietic necrosis virus,viral hemorrhagic septicemia virus,grass carp reovirus and spring viremia of carp virus.The detection limit was 3.2×10~(-12) ng·μL~(-1).The sensitivity of this method was 10-fold higher than that of a previously published RT-LAMP assay for detecting the Spajarup (Sp) serotype of IPNV.This method,aimed at detecting IPNV isolates that were currently prevalent in China,possessed the characteristics of strong specificity,high sensitivity and direct interpretation by the naked eyes.The IPNV RT-LAMP was successfully applied to determine the clinical samples,which indicated the IPNV RT-LAMP assay was suitable for the rapid and large-scale detections of IPNV in China.
2020年02期 v.27;No.79 90-98页 [查看摘要][在线阅读][下载 924K] [下载次数：3 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：2 ] - Liu Hai-xin;Wang Hong-wei;Cao Li-yan;Dante S Zarlenga;Ge Xu-ying;Zhang Yue;Yin Xue-ting;Zhang Rui-li;Ren Yu-dong;Huang Xiao-dan;Li Guang-xing;
The p65 protein is a functional subunit of NF-κB family and exhibits a crucial role in host immune and inflammatory responses,apoptosis and tumor proliferation if improperly-regulated.Given its ubiquitous association with nearly all the animal cells and its pleotropic functions,the gene encoding NF-κB p65 subunit was cloned and sequenced from porcine kidney (PK-15) cells.The gene was 1 662 bp in length,encoded a 553-amino acid protein and contained the prototypical NF-κB functional domains.Real-time quantitative RT-PCR and Western blot were used to characterize the transcription and expression levels of the p65 in different pig tissues.The results indicated that the p65 gene and protein were both broadly expressed in pig tissues,but most highly expressed in the intestine-associated lymph nodes and the lungs.To localize the recombinant protein in intestinal porcine epithelial cells (IPEC-J2),the gene was subcloned into the vector pEGFP (pEGFP-p65).Using fluorescence microscopy,the protein was found confined to the cytoplasm in normal cells;however,during porcine epidemic diarrhea virus (PEDV) infection,mRNA and protein expression were significantly up-regulated and the protein exhibited an overt tendency for nuclear translocalization consistent with a regulatory role in antiviral innate immunity.
2020年02期 v.27;No.79 99-107页 [查看摘要][在线阅读][下载 704K] [下载次数：3 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：3 ] - Sun Xing-sheng;Du Jia-yang;Liu Jia-fu;
Talin-1 head (hereinafter referred to as TH) is the head structure of talin protein,which contains a four-point-one-protein/ezrin/radixin/moesin (FERM) domain.Its F1 domain contains an unstructured loop of 30 amino acids (139-168),which does not interact with other domains.Because TH doesn't get the crystal structure and whether the unstructured loop has obvious influence on the TH secondary structure,therefore,the truncated talin-1 head Δ139-168 (hereinafter referred to as THΔ) was constructed and its structure and the impact of stability after truncation were analyzed.Molecular biology and structural biology methods were used to construct prokaryotic expression vectors of TH and THΔ,explore and optimize the expression conditions of recombinants,and they were purified by affinity chromatography and FPLC gel filtration chromatography.Finally,a large number of stable,high-purity protein samples were prepared successfully.The physicochemical properties and structural stability of the proteins were investigated by dynamic light scattering and circular dichroism.The results showed that the THΔ secondary structure of the truncated body did not change significantly,the structural stability was enhanced and the resistance to guanidine hydrochloride and high temperature was stronger.
2020年02期 v.27;No.79 108-115页 [查看摘要][在线阅读][下载 628K] [下载次数：3 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：7 ] - Hu Xiao-yang;Zeng Xiao;Xu Ying;Ding Cong;Zhang Dan-dan;Jia Zhen-zhen;Cao Yun-kao;
RanBP1 is a binding protein of Ran that plays a pivotal role in nucleocytoplasmic transport.In this study,the localization and possible functions of RanBP1 were examined,during the early embryonic development of mice.Immunofluorescence results showed that RanBP1 was mainly localized in cytoplasm at mitosis interphase,and its concentration was lower in nucleus and the lowest in nucleolus.With the formation of the spindle in the early embryonic cells,RanBP1 condensed area took the shape of spindle microtubule,the concentration of RanBP1 was low in the site of chromosome.During the formation of nucleus,RanBP1 concentrated in nucleus and there were few dots of RanBP1 around the nucleolus.These dots were lost after the nucleus full growth.The results showed that RanBP1 had important roles in nucleocytoplasmic transport,spindle formation and nuclear assembly in the early embryonic development of mice.
2020年02期 v.27;No.79 116-121页 [查看摘要][在线阅读][下载 905K] [下载次数：1 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Wang Feng;Li Rui;Qu Peng;Zhang Yuan-yuan;Li Chang-wen;Liu Fang-ping;
Salmonella gallinarum has shown multiple drug resistance (MDR),especially high level fluoroquinolone (FQ) resistance in recent years.To determine whether the active efflux system was responsible for high-level FQ resistance,this research studied AcrAB efflux pump in Salmonella gallinarum on molecular level.The resistant strains were induced by standard strain C79-13 with ciprofloxacin in vitro.With carbonylcyanide-p-chlorophenyl hydrazone (CCCP) as an energy inhibitor,efflux inhibition test initially showed the potential impact of efflux pump on drug resistance.Sequence analysis of acrA gene indicated that gene mutation of AcrAB efflux pump was not definitely associated with MDR and drug resistance level of Salmonella gallinarum.Detected by competitive RT-PCR,the mRNA expression of acrA and acrB genes in the resistant strains significantly increased (p<0.01) compared with that of the control strain C79-13.The mRNA expression level of acrB gene (increased from 1.6-to 2.9-folds) was consistent with that of acrA gene (increased from 1.6-to 2.8-folds),which increased with the drug resistance level.However,gene mutation of acrA gene showed no correlation with its mRNA expression level,indicating that gene mutation did not affect the expression of AcrAB pump itself.The results suggested that the overexpression rather than the gene mutation of AcrAB efflux pump was an important factor causing the high level drug resistance of Salmonella gallinarum.
2020年02期 v.27;No.79 122-129页 [查看摘要][在线阅读][下载 551K] [下载次数：2 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：2 ] - Hu Wan-jun;Ding Liang-jun;Chen Chun-li;Xu Jia;Li Ji-chang;
Toxocara canis (T.canis) is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a concentration gradient of the drug and to determine the inflammatory reaction produced by the infective T.canis larvae in mice.The present study was undertaken using the model nematode,T.canis,to investigate the effect of Milbemycin oxime on T.canis eggs and larvae.T.canis eggs were exposed to a concentration gradient of Milbemycin oxime in vitro,the higher concentration of Milbemycin oxime was,the lower percentage of infective stage larvae was.Light micrographs showed that Milbemycin oxime induced eggs dissolved and eggshell broken.Histological analyses of mice that stained with hematoxylin and eosin (H&E) showed in lower dosing (10~(-7) and 10~(-8) g·mL~(-1)) drug-treated groups,atrophy of alveolar space and interalveolar septum thickening appeared,inflammatory infiltrates accompanied with erythrocytes around blood vessels and bronchioles presented.In higher dosing (10~(-6),10~(-5) and 10~(-4) g·mL~(-1)) drug-treated groups,low-grade or no pathological changes occurred,indicating that Milbemycin oxime could obviously decrease the inflammatory reaction produced by the infection of T.canis larvae in vivo.
2020年02期 v.27;No.79 130-135页 [查看摘要][在线阅读][下载 868K] [下载次数：3 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：2 ] - Su Zhong-bin;Yan Yu-guang;Jia Yin-jiang;Sun Hong-min;Dong Shou-tian;Cao Yu-ying;
An airborne multi-spectral camera was used in this study to estimate rice yields.The experimental data were achieved by obtaining a multi-spectral image of the rice canopy in an experimental field throughout the jointing stage (July,2017) and extracting five vegetation indices.Vegetation indices and rice growth parameter data were compared and analyzed.Effective predictors were screened by using significance analysis and quantile and ordinary least square (OLS) regression models estimating rice yields were constructed.The results showed that a quantile regression model based on normalized difference vegetation indices (NDVI) and rice yields performed was best for τ=0.7 quantile.Thus,NDVI was determined as an effective variable for the rice yield estimation during the jointing stage.The accuracy of the quantile regression estimation model was then assessed using RMES and MAPE test indicators.The yields by this approach had better results than those of an OLS regression estimation model and showed that quantile regression had practical applications and research significance in rice yields estimation.
2020年02期 v.27;No.79 136-143页 [查看摘要][在线阅读][下载 748K] [下载次数：2 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：2 ] - Chen Hai-tao;Min Shi-yao;Li Long-hai;
The aims of this study were to achieve working stability and continuity of the straw fibre extruder (D200) to improve the transportation efficiency of pretreated straw materials mulch film.Based on a theoretical analysis of wheat straw friction characteristics and the mechanics model of wheat straw transport,a tilting variable-diameter spiral feeding device matched the designed straw fibre extruder(D200-type).Experimental researches were performed by using the orthogonal test method of the L_(16)(4~5) to obtain the optimal parameter combination.The spiral angle,the speed of the screw shaft and the moisture content of straw raw materials were selected as influencing factors,and feeding efficiency was selected as the objective indicator.The results showed that the spiral angle,the rotating speed of screw shaft and the moisture content of straw raw materials had very significant effects on the feeding efficiency(p<0.01).The order of the extent of the influence of parameters on the feeding efficiency of wheat straw raw materials from high to low was the moisture content,the spiral angle and the speed of screw shaft.When the maximum transfer efficiency per unit time of the inclined spiral feeding device was 1 040.8 kg·h~(-1),the spiral angle was 40?,the speed of screw shaft was 200 r·min~(-1) and the moisture content was 65%.Verification experiment proved the feasibility of straw fibre extruder designed.
2020年02期 v.27;No.79 144-151页 [查看摘要][在线阅读][下载 754K] [下载次数：4 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：3 ] - Fu Xing-yuan;Qin Tong;Sun Hao-nan;Shi Yang-ning;Meng Xiang-dong;Wang Yao;Zou Tie-an;
Several studies have shown a positive relationship between high quality outdoor environments and users' health.Education of agricultural professionals also demands high quality outdoor environments in order to promote students' wellbeing, which in turn supports scientific researches. This study analyzed relationship between students' actual uses and campus outdoor environments, identified what environmental characteristics that students prefered, how they used and why they participated in the outdoor activities. The results could be used as guidance of campus design and management. Investigation of three universities in Harbin provided 686 valid questionnaires. The results suggested that health awareness effectively promoted students' use frequencies of outdoor environments. Environment with "natural" and "cultural" characteristics, especially undulating landform, vibrant plants and landmarks in a serpentins design style attracted more uses. Female students showed more preferences on social interaction activities than males. Students who had good economic consumption levels and participated in outdoor activities frequntly in childhood prefered to join all the kinds of activities after university enrollment.
2020年02期 v.27;No.79 152-158页 [查看摘要][在线阅读][下载 559K] [下载次数：2 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：4 ] <正>Aims and Scope Journ,al of Northeast Agricultural Univer sity (English Edition) is a comprehensive academic journal on agricultural sciences sponsored by Northeast Agricultural University and distributed worldwide.It is a peer reviewed journal published quarterly and mainly publishes review and research articles that reflect the latest achievements on crop science,horticulture,plant protection,resource and
2020年02期 v.27;No.79 159页 [查看摘要][在线阅读][下载 220K] [下载次数：4 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：5 ]