Journal of Integrative Agriculture

Screening and Analysis of Proteins Interacting with TaPDK from Physiological Male Sterility Induced by CHA in Wheat

ZHANG Long-yu, ZHANG Gai-sheng, ZHAO Xin-liang , YANG Shu-ling

2013, 12(6): 941-950. DOI: 10.1016/S2095-3119(13)60314-7

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To further research the regulatory network of pyruvate dehydrogenase kinase (designated as TaPDK) in physiological male-sterility (PHYMS) of wheat induced by chemical hybridizing agent (CHA) SQ-1, an anther cDNA library was constructed, and the proteins interacting with TaPDK were screened via yeast two-hybrid technique. Subsequently, a few candidate proteins in nucleotide expression levels were detected by real-time quantitative PCR. Yeast-two hybrid screening was performed by mating yeast strain Y2HGold containing BD-TaPDK bait plasmid with yeast strain Y187 including anther cDNA library plasmid. Diploid yeast cells were plated on synthetic dropout nutrient medium (SD/-Ade/ -His/-Leu/-Trp) (QDO), and further were incubated on QDO medium containing AbA and X-α-Gal. The interactions between TaPDK and the proteins obtained from positive colonies were further confirmed by co-transformation validation. After plasmids DNA were extracted from blue colonies and sequenced, the sequences results were analyzed by bioinformatic methods. Finally, 24 colonies were obtained, including eight genes, namely non-specific lipid-transfer protein precursor (TanLTP), polyubiquitin (TaPUbi), glyceraldehyde-3-phosphate dehydrogenase, proliferating cell nuclear antigen (TaPCNA), CBS domain containing protein (TaCBS), actin, guanine nucleotide-binding protein beta subunit, chalcone synthase, and three new genes with unknown function. The results of quantitative RT-PCR showed that the expression levels of TanLTP, TaPUbi, and TaPCNA were obviously up-regulated in PHYMS anther, and TaCBS expression was only increased at the tricellular stage in PHYMS anther compared with in fertile lines. Whereas, the expression of TaPDK was obviously down-regulated in PHYMS lines. Collectively, these datas indicated that the majority of candidate proteins might be related to pollen abortion in PHYMS lines, which further suggested that TaPDK plays multiple roles in pollen development, besides participating in regulating pyruvate dehydrogenase complex activity.

QTL Mapping for Dough Mixing Characteristics in a Recombinant Inbred Population Derived from a Waxy×Strong Gluten Wheat (Triticum aestivum L.)

ZHENG Fei-fei, DENG Zhi-ying, SHI Cui-lan, ZHANG Xin-ye , TIAN Ji-chun

2013, 12(6): 951-961. DOI: 10.1016/S2095-3119(13)60315-9

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Protein and starch are the most important traits in determining processing quality in wheat. In order to understand the genetic basis of the influence of Waxy protein (Wx) and high molecular weight gluten subunit (HMW-GS) on processing quality, 256 recombinant inbred lines (RILs) derived from the cross of waxy wheat Nuomai 1 and Gaocheng 8901 were used as mapping population. DArT (diversity arrays technology), SSR (simple sequence repeat), HMW-GS, and Wx markers were used to construct the molecular genetic linkage map. QTLs for mixing peak time (MPT), mixing peak value (MPV), mixing peak width (MPW), and mixing peak integral (MPI) of Mixograph parameters were evaluated in three different environments. The genetic map comprised 498 markers, including 479 DArT, 14 SSR, 2 HMW-GS, and 3 Wx protein markers, covering 4 229.7 cM with an average distance of 9.77 cM. These markers were identified on 21 chromosomes. Eighteen additive QTLs were detected in three different environments, which were distributed on chromosomes 1A, 1B, 1D, 4A, 6A, and 7D. QMPT-1D.1 and QMPT-1D.2 were close to the Glu-D1 marker accounting for 35.2, 22.22 and 36.57% of the phenotypic variance in three environments, respectively. QMPV-1D and QMPV-4A were detected in all environments, and QMPV-4A was the nearest to Wx-B1. One minor QTL, QMPI-1A, was detected under three environments with the genetic distances of 0.9 cM from the nearest marker Glu-A1, explaining from 5.31 to 6.67% of the phenotypic variance. Three pairs of epistatic QTLs were identified on chromosomes 2D and 4A. Therefore, this genetic map is very important and useful for quality trait related QTL mapping in wheat. In addition, the finding of several major QTLs, based on the genetic analyses, further suggested the importance of Glu-1 loci on dough mixing characteristics.

Molecular Cloning and Characterization of a Novel Gene Involved in Fatty Acid Synthesis in Brassica napus L.

XIAO Gang, ZHANG Zhen-qian, LIU Rui-yang, YIN Chang-fa, WU Xian-meng, TAN Tai-long

2013, 12(6): 962-970. DOI: 10.1016/S2095-3119(13)60316-0

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Based on the sequence of a novel expressed sequence tag (EST), the full-length cDNA of 1 017 nucleotides was cloned from Brassica napus cv. Xiangyou 15 through rapid amplification of cDNA ends (RACE). The gene was designated as Bnhol34 (HQ585980), encoding a protein of 338 amino acids. BLAST analysis showed no high degree of sequence identity to any known gene. The calculated molecular weight of the Bnhol34 protein was 36.23 kDa, and the theoretical isoelectric point was 8.74. The Bnhol34 was also cloned from a high oleic acid mutant 854-1 through homologous cloning. There was no difference between the two Bnhol34 genes. Bnhol34 was localized in a tissue-specific manner in B. napus, and its expression level was about eight-fold greater in Xiangyou 15 seeds than in 854-1. The promoter region sequences of Bnhol34 were then isolated from Xiangyou 15 and 854-1, and a 93-bp deletion was found to occur in the Bnhol34 promoter region of 854-1. Three abscisic acid-responsive cis-elements (ABRE) were identified in the promoter region of Xiangyou 15. Real-time PCR analyses revealed that exogenous abscisic acid increased Bnhol34 expression by about four-fold in Xiangyou 15 seeds, yet did not change Bnhol34 expression in 854-1. It appeared that Bnhol34 might be abscisic acid insensitive in 854-1.

Statistic Analysis on Quantitative Characteristics for Developing the DUS Test Guideline of Ranunculus asiaticus L.

LIU Yan-fang, ZHANG Jian-hua, Lü Bo, YANG Xiao-hong, LI Yan-gang, WANG Ye, WANGJiang-min , ZHANG Hui, , GUAN Jun-jiao

2013, 12(6): 971-978. DOI: 10.1016/S2095-3119(13)60317-2

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Selection of quantitative characteristics, division of their expression ranges, and selection of example varieties are key issues on developing DUS Test Guidelines, which are more crucial for quantitative characteristics since their expressions vary in different degrees. Taking the development of DUS Test Guideline of Ranunculus asiaticus L. as an example, this paper applied statistic-based approaches for the analyses of quantitative characteristics. We selected 9 quantitative characteristics from 18 pre-selected characteristics, based on within-variety uniformity, stability between different growing cycles, and correlation among characteristics, by the analyses of coefficient of variation, paired-samples t-test and partial correlation. The expression ranges of the 9 selected quantitative characteristics were divided into different states using descriptive statistics and distribution frequency of varieties. Eight of the 9 selected quantitative characteristics were categorized as standard characteristics as they showed one peak in distribution frequency of 120 varieties in various expressions of the characteristics, whereas, plant height can be categorized as grouping characteristic since it gave two peaks, and can group the varieties into pot and cut varieties. Finally, box-plot was applied to visually select the example varieties, and varieties 7, 12, and 28 were determined as the example varieties for plant height. The methods described in this paper are effective for the selection of quantitative characteristics, division of expression ranges, and selection of example varieties in Ranunculus asiaticus L. for DUS test, and may also be interest for other plant genera.

Effects of Increased Night Temperature on Cellulose Synthesis and the Activity of Sucrose Metabolism Enzymes in Cotton Fiber

TIAN Jing-shan, HU Yuan-yuan, GAN Xiu-xia, ZHANG Ya-li, HU Xiao-bing, GOU Ling, LUO Hong-hai

2013, 12(6): 979-988. DOI: 10.1016/S2095-3119(13)60318-4

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Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures (control) in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase (AI) and alkaline invertase (NI) decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG (uridin diphosphate-glucose) during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.

Effects of Root Pruning on Non-Hydraulic Root-Sourced Signal, Drought Tolerance and Water Use Efficiency of Winter Wheat

MA Shou-chen, LI Feng-min, YANG Shen-jiao, LI Chun-xi, XU Bing-cheng , ZHANG Xu-cheng

2013, 12(6): 989-998. DOI: 10.1016/S2095-3119(13)60319-6

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Two pot experiments were conducted to study the effects of root pruning at the stem elongation stage on non-hydraulic root-sourced signals (nHRS), drought tolerance and water use efficiency of winter wheat (Triticum aestivum). The root pruning significantly reduced the root weight of wheat, but had no effect on root/shoot ratio at the two tested stages. At booting stage, specific root respiration of root pruned plants was significantly higher than those with intact roots (1.06 and 0.94 mmol g-1 s-1, respectively). The soil water content (SWC) at which nHRS for root pruned plants appeared was higher and terminated lower than for intact root plants, the threshold range of nHRS was markedly greater for root pruned plants (61.1-44.6% field water capacity) than for intact root plants (57.9-46.1% field water capacity). At flowering stage, while there was no significant difference in specific root respiration. The SWCs at which nHRS appeared and terminated were both higher for root pruned plants than for intact root plants. The values of chlorophyll fluorescence parameters, i.e., the effective photosystem II quantum yield ( PS II), the maximum photochemical efficiency of PS II (Fv/Fm), coefficient of photochemical quenching (qP), and coefficient of non-photochemical quenching (NPQ), in root pruned plants were significantly higher than in intact root plants, 7 d after withholding of water. Root pruned plants had significantly higher water use efficiency (WUE) than intact root plants in well-watered and medium drought soil, but not in severe drought condition. In addition, root pruning had no significant effect on grain yield in well-watered and medium drought soil, but significantly decreased grain yield in severe drought condition. In conclusion, the current study showed that root pruning significantly altered nHRS sensitivity and improved WUE of winter wheat in well-watered and medium drought soil, but lowered drought tolerance of winter wheat in severe drought soil. This suggests a possible direction of droughtresistance breeding and potential agricultural measure to improve WUE of winter wheat under semiarid conditions.

Fertilizer 15N Accumulation, Recovery and Distribution in Cotton Plant as Affected by N Rate and Split

YANG Guo-zheng, CHU Kun-yan, TANG Hao-yue, NIE Yi-chun , ZHANG Xian-long

2013, 12(6): 999-1007. DOI: 10.1016/S2095-3119(13)60320-2

Abstract ( ) PDF in ScienceDirect

N fertilization of 300 kg N ha-1 is normally applied to cotton crops in three splits: pre-plant application (PPA, 30%), first bloom application (FBA, 40%) and peak bloom application (PBA, 30%) in the Yangtze River Valley China. However, low fertilizer N plant recovery (NPR) (30-35%) causes problems such as cotton yield stagnation even in higher N rate, low profit margin of cotton production and fertilizer release to the environment. Therefore, it is questioned: Are these three splits the same significance to cotton N uptake and distribution? An outdoor pot trial was conducted with five N rates and 15N labeled urea to determine the recovery and distribution of 15N from different splits in cotton (Gossypium hirsutum L. cv. Huazamian H318) plant. The results showed that, cotton plant absorbed fertilizer 15N during the whole growing period, the majority during flowering for 18-20 d regardless of N rates (150-600 kg ha-1). Fertilizer 15N proportion to the total N accumulated in cotton plant increased with N rates, and it was the highest in reproductive organs (88% averaged across N rates) among all the plant parts. FBA had the highest NPR (70%), the lowest fertilizer N lose (FNL, 19%), and the highest contribution to the fertilizer 15N proportion to the total N (46%) in cotton plant, whereas PPA had the reverse effect. It suggests that FBA should be the most important split for N absorption and yield formation comparatively and allocating more fertilizer N for late application from PPA should improve the benefit from fertilizer.

Impact of Plant Density on the Formation of Potato Mimitubers Derived from Microtubers and Tip-Cuttings in Plastic Houses

JIN Hui, LIU Jun, SONG Bo-tao , XIE Cong-hua

2013, 12(6): 1008-1017. DOI: 10.1016/S2095-3119(13)60321-4

Abstract ( ) PDF in ScienceDirect

The potato minitubers have been widely used for the elite seed propagation to improve the seed potato system in China. However, little information is available for an efficient production of the minitubers with high plant density in the protected growing conditions like plastic houses. In present research, the minitubers of a wide-grown potato variety, Favorita, were produced with the microtubers from tissue culture and the tip-cuttings of the microtuber plants. Three plant densities, 200, 400 and 600 microtubers or plants m-2 were set up with the randomized block design of 3 replications and the experiment was repeated in 4 seasons in 2009-2010. The canopy development, light interception, dry weight production and partitioning, tuberization and tuber weight were investigated to elucidate the mechanism by which the plant density affects the formation and growth of the minitubers. The results showed that the number of the tubers formed per unite area was in line with the increase in plant density. The difference in leaf area index (LAI) between the plant densities, especially in early stage of the plant growth, resulted in more radiation interception and dry weight producing in higher plant density than in lower one. However, our analysis demonstrated that the conversion coefficient of the cumulative intercepted radiation to plant weight and the dry weight partition rate to the tubers were constant between plant densities, suggesting that less amount of the photoassimilates partitioned to individual tubers is causal for more small tubers in high plant density. A negative exponential curve model, determined by total number of tubers produced per unit area and the mean tuber weight, fitted well to the tuber size distribution pattern. The optimum plant density could be estimated from this model for a maximum production of the minitubers with desired size.

Genetics and Molecular Mapping of a High-Temperature Resistance Gene to Stripe Rust in Seeding-Stage in Winter Wheat Cultivar Lantian

MA Dong-fang, JING Jin-xue, HOU Dong-yuan, LI Qiang, ZHOU Xin-li, DU Jiu-yuan , LU Qing-lin

2013, 12(6): 1018-1025. DOI: 10.1016/S2095-3119(13)60322-6

Abstract ( ) PDF in ScienceDirect

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene(s) for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 (M169). Seedlings of the parents, and F1, F2 and F2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.

Isolation and Structural Speculation of Herbicide-Active Compounds from the Metabolites of Pythium aphanidermatum

ZHANG Li-hui, ZHANG Jin-lin, LIU Ying-chao, CAO Zhi-yan, HAN Jian-min, YANG Juan , DONG Jingao

2013, 12(6): 1026-1032. DOI: 10.1016/S2095-3119(13)60295-6

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Natural herbicides, or environment-friendly bioherbicides have been attracted more and more attentions. Isolation and structural identification of natural herbicide-active compounds from plant pathogens has been proved to be an effective approach for novel lead discovery of the pesticide development. In this study, the metabolites of the mutant strain PAM1, which obtained from PA1 of Pythium aphanidermatum (Eds.) Fitzp by ultraviolet radiation were separated and identified by HPLC, NMR, and IR. The results revealed that three active compounds including 4-hydroxy-3-methoxycinnamic acid and two indole derivatives, exhibited inhibition activity on the elongation of radical and coleoptile of Digtaria sanguinalis (L.) Scop.

Population Genetic Analysis of the Rice Stem Borer, Chilo suppressalis, in the South China

LIU Yu-di, HOU Mao-lin, WU Yu-chun , LIU Gui-qin

2013, 12(6): 1033-1041. DOI: 10.1016/S2095-3119(13)60323-8

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Genetic variation and patterns of genetic differentiation of the rice stem borer, Chilo suppressalis (Lepidoptera: Pyralidae), from the South China were analyzed using 6 microsatellite markers and two partial mtDNA (cox1 and cox2) regions. All of the 6 microsatellite loci were polymorphic in the studied seven populations. The allelic richness per population ranged between 5.67 and 14.00, and average HE and HO values were 0.6246-0.8329 and 0.2634-0.6061, respectively. As the mitochondrial genome is a single genetic locus, we only present results for the concatenated data set (cox1 plus cox2 gene sequences, 513 bp). The concatenated data showed high level of genetic diversity and there are 23 variable polymorphic sites among the 513 sites in concatenated data. Nearly all of (20 of 21) pairwise FST comparisons among populations showed genetic differentiation with moderate to high pairwise FST values based on microsatellite markers. However, for the mtDNA data, most of the seven populations did not show significant differentiation with other populations. The differences of population differentiation obtained with the two different genetic markers could be mainly attributed to the different mutation rates of microsatellite and mtDNA. There was not genetic structure existed in these studied populations based on microsatellite loci and mtDNA data. The analysis based on network, mismatch distribution, Tajima’s D and FS indicated that the studied populations were from the recent same ancestor or the same refuge and followed by a sudden demographic expansion condition.

Effects of Destruxin A on Hemocytes Morphology of Bombyx mori

FAN Ji-qiao, CHEN Xiu-run , HU Qiong-bo

2013, 12(6): 1042-1048. DOI: 10.1016/S2095-3119(13)60324-X

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Destruxin A (DA), a kind of cyclo-hexadepsipeptide isolated from entomopathogenic fungus, Metarhizium anisopliae, is an inhibitor of insect’s immunity. But its mechanism has not been clarified yet. In this study, the effects of DA on morphologic changes of in vivo and in vitro hemocytes of silkworm, Bombyx mori, were investigated by means of inverted phase contrast microscopy (IPCM), fluorescence microscopy (FCM) and environmental scanning electron microscopy (ESEM). The results indicated that DA was cytotoxic to granulohemocytes (GR) and plasmatocytes (PL). The LC50 values of DA against in vitro GR and PL of silkworm were 68.77 and 84.11 μg mL-1, respectively. However, the hemocytes in vivo were more susceptible to DA, although at the extremely low dose of 10 μL of 12.5 μg mL-1 for each insect (i.e., 0.036 μg g-1 body weight, or approximately 0.25 μg mL-1 hemolymph), DA could induce obviously morphologic alterations of hemocytes in vivo. The results imply that there might be some factors in silkworm’s hemolymph, which influence the interaction of DA and hemocytes.

Dosage Effects of Fadrozole on Growth and Development of Sex-Reversed Genetic Female Chickens

YANG Xiu-rong, JIANG He-sheng, ZHENG Jiang-xia, QU Lu-jiang, CHEN Si-rui, LI Jun-ying, XU Guiyun, YANG Ning

2013, 12(6): 1049-1053. DOI: 10.1016/S1671-2927(00)8886

Abstract ( ) PDF in ScienceDirect

Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. Chick embryos from a population of CAU3 egg-type were treated with different concentrations of Fadrozole prior to the sexual differentiation at E3.0 (st18). At hatch, the phenotypic sex and genetic sex were identified by vent sexing and genetic diagnosis with CHD1, respectively. Body weight and shank length of sex reversal were tested at 8 and 20 wk, respectively. Testicular development, oviduct and ovarian degeneration were observed and serum concentration of estradiol and testosterone were tested with radioimmunoassay (RIA) at 30 wk. The results showed that body weight and shank length of sexreversed females were not significantly different between low-dose groups (0.1, 0.3, and 0.5 mg for F1, F2, and F3, respectively) and high-dose groups (1.0 and 1.3 mg for F4 and F5, respectively) (P>0.05). Left and right testes or ovotestes in F2, F3, F4, and F5 groups were heavier than that of in F1 group (P<0.05). While the gonad weight of treatment groups were less than that in male control (P<0.05), oviduct weight in F2, F3, F4, and F5 groups were significant differences compared with female control and F1 group (P<0.05). Egg number from onset of laying egg to 30 wk in F4 and F5 groups were less than in female control, F1 and F2 groups (P<0.05). Serum testosterone level in F5 group was significant higher compared with female control, F1, F2, F3, and F4 groups (P<0.05), but significant lower compared with male control (P<0.05). While concentration of serum estradiol in F5 group was significant lower compared with female control, F1, F2, and F4 groups (P<0.05). In conclusion, the concentration of Fadrozole do not affect postnatal growth of sex-reversed female chicken and the degree of sex-reversed females elevate with the increase of Fadrozole concentration at sex maturity.

GDNF Up-Regulates c-Myc Transcription via the PI3K/Akt Pathway to Promote Dairy Goat Male Germline Stem Cells (mGSC) Proliferation

SUN Jun-wei, ZHU Hai-jing, LIU Chao, LI Ming-zhao , HUA Jin-lian

2013, 12(6): 1054-1065. DOI: 10.1016/S2095-3119(13)60263-4

Abstract ( ) PDF in ScienceDirect

Studies have demonstrated that regulation of GDNF on male germline stem cells (mGSCs) mainly through Ras/Erk1/2, Src family kinase and PI3K/Akt signaling pathways, but the signaling pathways GDNF-mediated are different when the species and cell lines varied. Whether GDNF regulates self-renewal of mGSCs isolated from livestock has not been reported. Here, we purified mGSCs from dairy goat testis using mixed enzymes and fibronectin. Immunofluoresce staining revealed the cultured dairy mGSCs expressed Vasa, Nanos2, Ngn3, Tert, Dazl, Lin28, Oct4, CD49f, Stra8 and GFRa1, reflecting that these cells were mGSCs phenotype. Then we cultured these dairy goat mGSCs in different concentrations of GDNF (0, 5, 10, or 20 ng mL-1) to optimize the best concentration of GDNF to sustain the dairy goat mGSCs self-renewal, after that the inhibitor of PI3K (LY294002, 10 μmol L-1) was added to the medium which contains the optimal concentration of GDNF we obtained by experiments. The mGSCs cultured in different media were compared through the population doubling time (PDT), capacity of cell proliferation evaluated by PCNA and BrdU immunofluorescence staining, RT-PCR, QRT-PCR, Western blotting and flow cytometry. Results showed that 10 ng mL-1 was the optimal concentration of GDNF to maintain goat mGSCs self-renewal and GDNF up-regulates c-Myc transcription via the PI3K/Akt pathway to promote goat mGSCs proliferation. This study provides us an efficient model to study the mechanism in mGSCs proliferation and differentiation in goat, and has important implications in unveiling signaling pathways in livestock GSCs.

Effect of PMSG/hCG Superovulation on Mouse Embryonic Development

WU Bao-jiang, XUE Hong-yan, CHEN Li-ping, DAI Yan-feng, GUO Ji-tong, , LI Xi-he

2013, 12(6): 1066-1072. DOI: 10.1016/S2095-3119(13)60325-1

Abstract ( ) PDF in ScienceDirect

Kunming mouse strain is widely used in China, and the superovulation was administrated with 10 IU PMSG combined with 10 IU hCG. In this study, the effects of the exogenous gonadotropins on superovulation of Kunming mice and embryo quality derived from the superovulated mice were assessed. Female mice at 6-8-wk old were superovulated with 0, 5, 7.5 and 10 IU PMSG/hCG and mated with male mice. The embryos were retrieved at 2.5 d post coitum. No statistic difference was observed for the number of 2-cell embryos collected per mouse between control and 5 IU PMSG/hCG treatment group, but the number significantly increased for 7.5 and 10 IU PMSG/hCG treatment group (P<0.05). The average number of 4- cell and 8-cell embryos collected from each mouse significantly differed between control and 5, 7.5, 10 IU PMSG/hCG treatment groups (P<0.05). When 8-cell embryos derived from mice administrated with 0, 5, 7.5 and 10 IU PMSG/hCG were cultured in KSOM, the blastocyst development rates were 88.1, 94.7, 96.1 and 94.3%, respectively, which were similar to control (P>0.05). This indicated that exogenous gonadotropins have no effects on development of Kunming mouse embryos. The quality of blastocyst was assessed by labelling with Hoechst and propidium iodide for inner cell mass and trophectoderm cells, the result showed that ICM/TE ratio significantly decreased for 10 IU PMSG/hCG treatment group compared with control, 5 and 7.5 IU PMSG/hCG treatment group (P<0.05). This suggested that the embryo quality of Kunming mouse has been affected by high dose of gonadotropins.

Lactic Acid Reduces LPS-Induced TNF- and IL-6 mRNA Levels Through Decreasing I B Phosphorylation

XU Guang-yong, JIANG Jin-qi, WANG Ming, LI Jie, SU Jing-liang , REN Xiao-ming

2013, 12(6): 1073-1078. DOI: 10.1016/S2095-3119(13)60326-3

Abstract ( ) PDF in ScienceDirect

This study explored the effects over time of lactic acid (LA) on I Bα phosphorylation and nuclear factor-kappa B (NF- B) p65 protein expression, and on tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) mRNA levels in rat intestinal mucosa microvascular endothelial cells (RIMMVECs) stimulated by lipopolysaccharide (LPS). I B , phosphorylated I B (p-I B ) and p65 protein levels were monitored by Western blot analysis, and TNF- and IL-6 mRNA levels were analyzed using real-time PCR. LA treatment reduced TNF- and IL-6 mRNA levels in LPS-stimulated RIMMVECs, with the greatest effect being after 3 h. The highest inhibitory effect of LA on I B phosphorylation to prevent activation of NFB was after 6 h. These results suggest that LA reduces TNF- and IL-6 mRNA levels through decreasing I B phosphorylation and blocking the dissociation of IKK complex, which prevents activation of NF- B.

Single and Combined Effects of As (III) and Acetochlor on Phosphatase Activity in Soil

ZHANG Yun, ZHANG Feng, ZHANG Guan-cai , GUAN Lian-zhu

2013, 12(6): 1079-1086. DOI: 10.1016/S2095-3119(13)60327-5

Abstract ( ) PDF in ScienceDirect

The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentrations of acetochlor and As individually and simultaneously. The results showed that acetochlor, As only, and combined pollution all clearly inhibited soil phosphatase activity. The maximum inhibition ratios of soil phosphatase activity by acetochlor, As only and combined pollution were 36.44, 74.12 and 61.29%, respectively. Two kinetic models, ν=c/(1+bi) (model 1) and ν=c(1+ai)/(l+bi) (model 2), were used to describe the relationship between the concentrations of As and acetochlor and the activity of soil phosphatase. The semi-effect dose (ED50) values induced by As and acetochlor stress based on the inhibition of soil phosphatase were 18.1 and 33.11 mg kg-1, respectively, according to calculation by model 1. The interactive effect of acetochlor with As on soil phosphatase primarily consisted of significant antagonism effects at the higher concentrations tested. The step regression results show that the toxicity order was As (III)>acetochlor>As (III)×acetochlor throughout the incubation period.

Microbial Community Dynamics During Biogas Slurry and Cow Manure Compost

ZHAO Hong-yan, LI Jie, LIU Jing-jing, Lü Yu-cai, WANG Xiao-fen , CUI Zong-jun

2013, 12(6): 1087-1097. DOI: 10.1016/S2095-3119(13)60328-7

Abstract ( ) PDF in ScienceDirect

This study evaluated the microbial community dynamics and maturation time of two compost systems: biogas slurry compost and cow manure compost, with the aim of evaluating the potential utility of a biogas slurry compost system. Denaturing gradient gel electrophoresis (DGGE), gene clone library, temperature, C/N ratio, and the germination index were employed for the investigation, cow manure compost was used as the control. Results showed that the basic strip and dominant strips of the DGGE bands for biogas slurry compost were similar to those of cow manure compost, but the brightness of the respective strips for each system were different. Shannon-Weaver indices of the two compost systems differed, possessing only 22% similarity in the primary and maturity stages of the compost process. Using bacterial 16S rRNA gene clone library analysis, 88 bacterial clones were detected. Further, 18 and 13 operational taxonomic units (OTUs) were present in biogas slurry and cow manure compost, respectively. The 18 OTUs of the biogas slurry compost belonged to nine bacterial genera, of which the dominant strains were Bacillus sp. and Carnobacterium sp.; the 13 OTUs of the cow manure compost belonged to eight bacterial genera, of which the dominant strains were Psychrobacter sp., Pseudomonas sp., and Clostridium sp. Results demonstrated that the duration of the thermophilic phase (more than 50°C) for biogas slurry compost was 8 d less than the according duration for cow manure compost, and the maturation times for biogas slurry and cow manure compost were 45 and 60 d, respectively. It is an effective biogas slurry assimilate technology by application of biogas slurry as nitrogen additives in the manufacture of organic fertilizer.

Genetic Improvement of Root Growth Contributes to Efficient Phosphorus Acquisition in maize (Zea mays L.)

ZHANG Yi-kai, CHEN Fan-jun, CHEN Xiao-chao, LONG Li-zhi, GAO Kun, YUAN Li-xing, ZHANG Fu-suo, MI Guo-hua

2013, 12(6): 1098-1111. DOI: 10.1016/S2095-3119(13)60329-9

Abstract ( ) PDF in ScienceDirect

Maize plants adapt to low phosphorus (P) stress by increasing root growth. It is of importance to know the extent to which genetic improvement of root growth can enhance P acquisiton. In the present study, the contribution of root growth improvement to efficient P acquisition was evaluated in two soils using T149 and T222, a pair of near isogenic maize testcrosses which were derived from a backcross BC4F3 population. T149 and T222 showed no difference in shoot biomass and leaf area under normal growth conditions, but differed greatly in root growth. T149 had longer lateral roots and a larger root surface area compared to T222. In calcareous soil, when P was insufficient, i.e., when P was either supplied as KH2PO4 at a concentration of 50 mg P kg-1 soil, or in the form of Phy-P, Ca3-P or Ca10-P, a 43% increase in root length in T149 compared to T222 resulted in an increase in P uptake by 53%, and shoot biomass by 48%. In acid soil, however, when P supply was insufficient, i.e., when P was supplied as KH2PO4 at a concentration of 100 mg P kg-1 soil, or in the form of Phy-P, Fe-P or Al-P, a 32% increase in root length in T149 compared to T222 resulted in an increase in P uptake by only 12%, and shoot biomass by 7%. No significant differences in the exudation of organic acids and APase activity were found between the two genotypes. It is concluded that genetic improvement of root growth can efficiently increase P acquisition in calcareous soils. In acid soils, however, improvements in the physiological traits of roots, in addition to their size, seem to be required for efficient P acquisition.

Identification of Behavior of Voluntary Traceability and Analysis of Its Determinants: A Case Study of Hog Slaughtering and Processing Firms in Zhejiang Province, China

ZHOU Jie-hong, YAN Zhen , LIU Qing-yu

2013, 12(6): 1112-1121. DOI: 10.1016/S2095-3119(13)60330-5

Abstract ( ) PDF in ScienceDirect

In recent years, the Chinese government has highlighted the importance of adopting hog safety/quality traceability, and a growing amount of research continues to entice firms to adopt traceability systems. In this study, a survey was conducted on a sample of pig slaughtering and processing firms in Zhejiang, China through personal interviews and emails. The aim of this study was to examine the determinants of firm behavior on the implementation of voluntary traceability systems with more stringent standards and controls than those of the mandatory system in China. The results revealed that motivation based on product quality improvement, capital ability and role perception (business type) had significantly positive relationships with a firm’s voluntary traceability. Other incentives, such as operation improvement, recall risk reduction, reduced occurrence of safety issues, and technical strength were not found to be supportive in our study. This study provides an opportunity to better understand the determinants of firm behavior on voluntary traceability, particularly in light of the fact that some Chinese firms are facing the threat of criminal action for the use of illegal additives and the abuse of Clenbuterol. Policy recommendations on encouraging the implementation of pork safety voluntary traceability by hog slaughtering and processing firms are also discussed.

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