Fruit development and ripening is a complex procedure (Malus×domestica Borkh.) and can be caused by various factors such as cell structure, cell wall components, and cell wall hydrolytic enzymes.  In our study, we focused on the variations in fruit firmness, cell wall morphology and components, the activity of cell wall hydrolytic enzymes and the expression patterns of associated genes during fruit development in two different types of apple cultivars, the hard-crisp cultivar and the loose-crisp cultivar.  In this paper, the aim was to find out the causes of the texture variations between the different type cultivars.  Cell wall materials (CWMs), hemicellulose and cellulose content were strongly associated with variations in fruit firmness during the fruit development.  The content of water soluble pectin (WSP) and chelator soluble pectin (CSP) gradually increased, while the content of ionic soluble pectin (ISP) showed inconsistent trends in the four cultivars.  The activities of polygalacturonase (PG), β-galactosidase (β-gal), cellulase (CEL), and pectate lyase (PL) gradually increased in four cultivars.  And the activities of PG, β-gal, and CEL were higher in ‘Fuji’ and ‘Honeycrisp’ fruit with the fruit development, while the activity of PL of ‘Fuji’ and ‘Honeycrisp’ was lower than that of ‘ENVY’ and ‘Modi’.  Both four cultivars of fruit cells progressively became bigger as the fruit expanded, with looser cell arrangements and larger cell gaps.  According to the qRT-PCR, the relative expression levels of MdACO and Mdβ-gal were notably enhanced.  Our study showed that there were large differences in the content of ISP and hemicellulose, the activity of PL and the relative expression of Mdβ-gal between two different types of apple cultivars, and these differences might be responsible for the variations in the texture of the four cultivars.

Tomato mottle mosaic virus (ToMMV), an economically important species of the genus Tobamovirus, causes significant loss in yield and quality of tomato fruits.  Here, we identified the Shandong isolate of ToMMV (ToMMV-SD) collected from symptomatic tomato fruits in Weifang, Shandong Province of China.  ToMMV-SD caused symptoms such as severe mosaic, mottling, and necrosis of tomato leaves, yellow spot and necrotic lesions on tomato fruits.  The obtained full genome of ToMMV-SD was 6 399 nucleotides (accession number MW373515) and had the highest identity of 99.5% with that of isolate SC13-051 from the United States of America at the genomic level.  The infectious clone of ToMMV-SD was constructed and induced clear mosaic and necrotic symptoms onto Nicotiana benthamiana leaves.  Several commercial tomato cultivars, harboring Tm-2² resistance gene, and pepper cultivars, containing L resistance gene, were susceptible to ToMMV-SD.  Plants of Solanum melongena (eggplant) and Brassica pekinensis (napa cabbage) showed mottling symptoms, while N. tabacum cv. Zhongyan 100 displayed latent infection.  ToMMV-SD did not infect plants of N. tabacum cv. Xanthi NN, Brassica rapa ssp. chinensis (bok choy), Raphanus sativus (radish), Vigna unguiculata cv. Yuanzhong 28-2 (cowpea), or Tm-2² transgenic N. benthamiana.  A quintuplex RT-PCR system differentiated ToMMV from tomato mosaic virus, tomato brown rugose fruit virus, tobacco mosaic virus, and tomato spotted wilt virus, with the threshold amount of 0.02 pg.  These results highlight the threat posed by ToMMV to tomato and pepper cultivation and offer an efficient detection system for the simultaneous detection of four tobamoviruses and tomato spotted wilt virus infecting tomato plants in the field. 

Inappropriate tillage practices and nitrogen (N) management have become seriously limitations for maize (Zea mays L.) yield and N use efficiency (NUE) in the North China Plain (NCP).  In the current study, we examined the effects of strip deep rotary tillage (ST) combined with controlled-release (CR) urea on maize yield and NUE, and determined the physiological factors involved in yield formation and N accumulation during a 2-year field experiment.  Compared with conventional rotary tillage (RT) and no-tillage (NT), ST increased the soil water content and soil mineral N content (N_min) in the 20–40 cm soil layer due to reduction by 10.5 and 13.7% in the soil bulk density in the 0–40 cm soil layer, respectively.  Compared with the values obtained by common urea (CU) fertilization, CR increased the N_min in the 0–40 cm soil layers by 12.4 and 10.3% at the silking and maturity stages, respectively.  As a result, root length and total N accumulation were enhanced under ST and CR urea, which promoted greater leaf area and dry matter (particularly at post-silking), eventually increasing the 1 000-kernel weight of maize.  Thus, ST increased the maize yield by 8.3 and 11.0% compared with RT and NT, respectively, whereas CR urea increased maize yield by 8.9% above the values obtained under CU.  Because of greater grain yield and N accumulation, ST combined with CR urea improved the NUE substantially.  These results show that ST coupled with CR urea is an effective practice to further increase maize yield and NUE by improving soil properties and N supply, so it should be considered for sustainable maize production in the NCP (and other similar areas worldwide).

The jasmonate ZIM domain (JAZ) protein belongs to the TIFY ((TIF[F/Y]XG) domain protein) family, which is composed of several plant-specific proteins that play important roles in plant growth, development, and defense responses.  However, the mechanism of the sorghum JAZ family in response to abiotic stress remains unclear.  In the present study, a total of 17 JAZ genes were identified in sorghum using a Hidden Markov Model search.  In addition, real-time quantification polymerase chain reaction (RT-qPCR) was used to analyze the gene expression patterns under abiotic stress.  Based on phylogenetic tree analysis, the sorghum JAZ proteins were mainly divided into nine subfamilies.  A promoter analysis revealed that the SbJAZ family contains diverse types of promoter cis-acting elements, indicating that JAZ proteins function in multiple pathways upon stress stimulation in plants.  According to RT-qPCR, SbJAZ gene expression is tissue-specific.  Additionally, under cold, hot, polyethylene glycol, jasmonic acid, abscisic acid, and gibberellin treatments, the expression patterns of SbJAZ genes were distinctly different, indicating that the expression of SbJAZ genes may be coordinated with different stresses.  Furthermore, the overexpression of SbJAZ1 in Escherichia coli was found to promote the growth of recombinant cells under abiotic stresses, such as PEG 6000, NaCl, and 40°C treatments.  Altogether, our findings help us to better understand the potential molecular mechanisms of the SbJAZ family in sorghum in response to abiotic stresses.

Bleeding canker, a devastating disease of pear trees (Pyrus pyrifolia L.), was first reported in the 1970s in Jiangsu, China and more recently in other provinces in China.  Trees infected with bleeding canker pathogen, Dickeya fangzhongdai, develop cankers on the trunks and branches, and a rust-colored mixture of bacterial ooze and tree sap could be seen all over the trunks and branches.  In this study, we provided detail descriptions of the symptoms and epidemiology of bleeding canker disease.  Based on pathogenic and phenotypic characterizations, we identified the causal agent of bleeding canker of pear as D. fangzhongdai.  Dickeya fangzhongdai strains isolated from pear were also pathogenic on Solanum tuberosum, Brassica pekinensis, Lycopersicon esculentum, and Phalaenopsis aphrodite based on artificial inoculation, and the pathogen were more virulent on potato than that of D. solani strain.  This study provides new information about this disease and bleeding canker disease of pear.

Plant virus disease is one of the major causes of biological disasters in agriculture worldwide.  Given the complexity of transmission media and plant disease infection mechanisms, the prevention and control of plant viral diseases is a great challenge, and an efficient green pesticide is urgently needed.  For this reason, when developing candidate drug leads to regulate plant viruses, pesticide experts have focused on characteristics such as low pesticide resistance, eco-friendliness, and novel mechanism.  Researchers have also theoretically investigated the molecular targets of viruses infecting agricultural crops.  Antiviral screening models have been constructed based on these molecular targets, and the mechanisms of commercial drugs and high-activity compounds have been extensively investigated.  After screening, some compounds have been applied in the field and found to have good commercial prospects; these drugs may be used to create new green antiviral pesticides to control plant viruses.  This paper reviews the screening, mode of action, development and application of recently used plant-based antiviral agents.

Understanding the potential drought characteristics under climate change is essential to reduce vulnerability and establish adaptation strategies, especially in the Huang-Huai-Hai Plain (3H Plain), which is a major grain production area in China.  In this paper, we investigated the variations in drought characteristics (drought event frequency, duration, severity, and intensity) for the past 50 years (1961–2010) and under future scenarios (2010–2099), based on the observed meteorological data and the Representative Concentration Pathway (RCP) 8.5 scenario, respectively.  First, we compared the applicability of three climatic drought indices: the standardized precipitation index (SPI), the standardized precipitation evapotranspiration index based on the Penman-Monteith equation (SPEI-PM) and the same index based on the Thornthwaite equation (SPEI-TH) to correlate the recorded agricultural drought areas.  Then, we analyzed the drought characteristics using ‘run theory’ for both historical and the future RCP 8.5 scenario based on the best performing index.  Correlation analyses between drought indices and agricultural drought areas showed that SPEI-PM performed better than SPI and SPEI-TH in the 3H Plain.  Based on the results of SPEI-PM, drought risks including duration, severity and intensity during 1961–2010 showed an decreasing trend.  However, under the RCP 8.5 scenario, drought is expected to rise in frequency, duration, severity, and intensity from 2010–2099, although drought components during the 2010–2039 are predicted to be milder compared with historical conditions.  This study highlights that the estimations for atmospheric evaporative demand would create differences in the prediction of long-term drought trends by different drought indices.  The results of this study can help inform researchers and local policy makers to establish drought management strategies.

   The aim of the current study was to investigate the effects of a lactic acid bacteria inoculant (Lactobacillus plantarum, LP), fibrolytic enzyme (EN), combination of LP and EN (LP+EN) on fermentation quality, nutritive characteristics and in vitro digestibility of total mixed ration (TMR) silages containing 0, 7.5 and 15.0% (on dry matter basis) of rape (Brassica campestris L.) straw (RS) (denoted as CTMR, LTMR and MTMR, respectively).  After ensiling for 60 days, TMR silages without additives were well preserved, but MTMR had higher pH than CTMR and LTMR. There were no differences in other parameters of fermentation quality, microbial composition, nutrition and in vitro digestibility between CTMR and LTMR except for yeast and mold number and crude protein (CP) content. CTMR and LTMR silage had higher CP content, in vitro neutral detergent fiber digestibility (IVNDFD) and in vitro acid detergent fiber digestibility (IVADFD), lower acid detergent fiber (ADF) content than MTMR silage.  LP and EN decreased pH and increased dry matter (DM) recovery of TMR silages. LP+EN improved the fermentation quality, nutritive characteristics and in vitro digestibility of TMR silages, showed by lower pH, ADF content, higher lactic acid content, in vitro dry matter digestibility (IVDMD) and IVNDFD.  Therefore, It was suggested that TMR silage contained 7.5% RS on a DM basis and treated with LP+EN can be as a useful feed for ruminant.

Planting grass and legume mixtures on improved grasslands has the potential advantage of realizing both higher yields and lower environmental pollution by optimizing the balance between applied N fertilizer and the natural process of legume biological nitrogen fixation. However, the optimal level of N fertilization for grass-legume mixtures, to obtain the highest yield, quality, and contribution of N2 fixation, varies with species. A greenhouse pot experiment was conducted to study the temporal dynamics of N2 fixation of alfalfa (Medicago sativa L.) grown alone and in mixture with smooth bromegrass (Bromus inermis Leyss.) in response to the addition of fertilizer N. Three levels of N (0, 75, and 150 kg ha–1) were examined using 15N-labeled urea to evaluate N2 fixation via the 15N isotope dilution method. Treatments were designated N0 (0.001 g per pot), N75 (1.07 g per pot) and N150 (2.14 g per pot). Alfalfa grown alone did not benefit from the addition of fertilizer N; dry matter was not significantly increased. In contrast, dry weight and N content of smooth bromegrass grown alone was increased significantly by N application. When grown as a mixture, smooth bromegrass biomass was increased significantly by N application, resulted in a decrease in alfalfa biomass. In addition, individual alfalfa plant dry weight (shoots+roots) was significantly lower in the mixture than when grown alone at all N levels. Smooth bromegrass shoot and root dry weight were significantly higher when grown with alfalfa than when grown alone, regardless of N application level. When grown alone, alfalfa’s N2 fixation was reduced with N fertilization (R2=0.9376, P=0.0057). When grown in a mixture with smooth bromegrass, with 75 kg ha–1 of N fertilizer, the percentage of atmospheric N2 fixation contribution to total N in alfalfa (%Ndfa) had a maximum of 84.07 and 83.05% in the 2nd and 3rd harvests, respectively. Total 3-harvest %Ndfa was higher when alfalfa was grown in a mixture than when grown alone (shoots: |t|=3.39, P=0.0096; root: |t|=3.57, P=0.0073). We believe this was due to smooth bromegrass being better able to absorb available soil N (due to its fibrous root system), resulting in lower soil N availability and allowing alfalfa to develop an effective N2 fixing symbiosis prior to the 1st harvest. Once soil N levels were depleted, alfalfa was able to fix N2, resulting in the majority of its tissue N being derived from biological nitrogen fixation (BNF) in the 2nd and 3rd harvests. When grown in a mixture, with added N, alfalfa established an effective symbiosis earlier than when grown alone; in monoculture BNF did not contribute a significant portion of plant N in the N75 and N150 treatments, whereas in the mixture, BNF contributed 17.90 and 16.28% for these treatments respectively. Alfalfa has a higher BNF efficiency when grown in a mixture, initiating BNF earlier, and having higher N2 fixation due to less inhibition by soil-available N. For the greatest N-use-efficiency and sustainable production, grass-legume mixtures are recommended for improving grasslands, using a moderate amount of N fertilizer (75 kg N ha–1) to provide optimum benefits.

The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV) and porcine circovirus type 2 (PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/ municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay (ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14% (34/372), 50.00% (186/372), 37.10% (138/372) and 3.23% (12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61% (6/372), 4.03% (15/372), 0.27% (1/372), 0.27% (1/372) and 0.81% (3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.

In this study, four strains of Toxoplasma gondii with the same genetic type (Type I) originated from chicken, human, cat and swine were used to compare the immune responses in resistant chicken host to investigate the relationships between the parasite origins and the pathogenicity in certain host. A total of 300, 10-day-old chickens were allocated randomly into five groups which named JS (from chicken), CAT (from cat), CN (from swine), RH (from human) and a negative control group (–Ve) with 60 birds in each group. Tachyzoites of four different T. gondii strains (JS, CAT, CN and RH) were inoculated intraperitoneally with the dose of 1×107 in the four designed groups, respectively. The negative control (–Ve) group was mockly inoculated with phosphate-buffered saline (PBS) alone. Blood and spleen samples were obtained on the day of inoculation (day 0) and at days 4, 11, 25, 39 and 53 post-infection to screen the immunopathological changes. The results demonstrated some different immune characters of T. gondii infected chickens with that of mice or swine previous reported. These differences included up-regulation of major histocompatibility complex class II (MHC II) molecules in the early stage of infection, early peak expressions of interleukin (IL)-12 (IL-12) and -10 (IL-10) and long keep of IL-17. These might partially contribute to the resistance of chicken to T. gondii infection. Comparisons to chickens infected with strains from human, cat and swine, chickens infected with strain from chicken showed significant high levels of CD4+ and CD8+ T cells, interferon gamma (IFN-γ), IL-12 and IL-10. It suggested that the strain from chicken had different ability to stimulate cellular immunity in chicken.

The bsd-pg (bundle sheath defective pale green) mutant is a novel maize mutation, controlled by a single recessive gene, which was isolated from offspring of maize plantlets regenerated from tissue callus of the maize inbred line 501. The characterization was that the biogenesis and development of the chloroplasts was mainly interfered in bundle sheath cells rather than in mesophyll cells. For mapping the bsd-pg, an F2 population was derived from a cross between the mutant bsd-pg and an inbred line Xianzao 17. Using specific locus amplified fragment sequencing (SLAF-Seq) technology, a total of 5 783 polymorphic SLAFs were analysed with 1 771 homozygous alleles between maternal and paternal parents. There were 49 SLAFs, which had a ratio of paternal to maternal alleles of 2:1 in bulked normal lines, and three trait-related candidate regions were obtained on chromosome 1 with a size of 3.945 Mb. For the fine mapping, new simple sequence repeats (SSRs) markers were designed by utilizing information of the B73 genome and the candidate regions were localized a size of 850 934 bp on chromosome 1 between umc1603 and umc1395, including 35 candidate genes. These results provide a foundation for the cloning of bsd-pg by map-based strategy, which is essential for revealing the functional differentiation and coordination of the two cell types, and helps to elucidate a comprehensive understanding of the C4 photosynthesis pathway and related processes in maize leaves.

In order to establish double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for detection of duck or goose flavivirus, polyclonal antibody against the flavivirus strain JS804 in geese and monoclonal antibody against the E protein of flavivirus strain JS804 in geese were used as the capture antibody and detection antibody, respectively. The optimal dilution of the capture antibody and detecting antibody capable of detecting the flavivirus strain JS804 in geese were 1:3 200 and 1:160 in the check-board titration, respectively. The reaction time of sample was 1 h, and the optimal working dilution of HRP-labeled goat-anti-mouse IgG was 1:10 000. The positive standard value was 0.247 (OD450 nm). The geese flavivirus could be detected at a minimal concentration of 1.875 μg mL-1. The ELISA had no cross-reaction with Newcastle disease virus (NDV), Avian influenza virus (AIV), Infectious bronchitis virus (IBV), Infectious bursal disease virus (IBDV), Duck hepatitis virus (DHV), and Gosling plague virus (GPV). Twenty clinical samples were detected by the DAS-ELISA and RT-PCR respectively, with the agreement rate of 75%. The results revealed that the DAS-ELISA possessed favorable specificity and higher sensitivity, indicating a suitable method for rapid detection of the duck or goose flavivirus.

The temperature difference between an urban space and surrounding non-urban space is called the urban heat island effect (UHI). Global terrestrial evapotranspiration (ET) can consume 1.4803×1023 joules (J) of energy annually, which is about 21.74% of the total available solar energy at the top of atmosphere, whereas annual human energy use is 4.935×1020 J, about 0.33% of annual ET energy consumption. Vegetation ET has great potential to reduce urban and global temperatures. Our literature review suggests that vegetation and urban agricultural ET can reduce urban temperatures by 0.5 to 4.0°C. Green roofs (including urban agriculture) and water bodies have also been shown to be effective ways of reducing urban temperatures. The cooling effects on the ambient temperature and the roof surface temperature can be 0.24-4.0°C and 0.8-60.0°C, respectively. The temperature of a water body (including urban aquaculture) can be lower than the temperature of the surrounding built environment by between 2 and 6°C, and a water body with a 16 m2 surface area can cool up to 2 826 m3 of nearby space by 1°C. Based on these findings, it can be concluded that the increase of evapotranspiration in cities, derived from vegetation, urban agriculture, and water body, can effectively mitigate the effect of urban heat islands.

One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a rural area surrounding Funing, China. Fifty-three chickens were antibody-positive and 21 chickens were antigen positive. Hearts, brains, spleens, lungs, livers, and kidneys of 21 antibody or antigen-positive chickens were bioassayed in mice. One strain of T. gondii was isolated from 1 of 21 (4.76%) chickens. The isolated T. gondii killed all of the inoculated mice. Genotyping of this isolate using polymorphisms at the loci 5´-SAG2, 3´-SAG2, SAG3, cB21-4, L358, BTUB, and GRA6 revealed that it was Type I. These indicated that it was virulent for mice. This is the first report of isolation of T. gondii from chickens in China.

Shepherd’s purse seeds were collected from winter wheat fields and road sides in Hebei Province, China. Their sensitivitiesto tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse. Results revealed that HB-1, HB-2, HB-3, HB-4, HB-6, HB-7, HB-17, HB-18, HB-19, HB-20, HB-21, and HB-22 populations were susceptible to tribenuronmethylcharacterised by very low GR50 values of about 0.10 g a.i. ha-1. On the other hand, populations HB-15 and HB-16had moderate resistance to tribenuron-methyl with resistance indices (RI) ranging from 10-100 folds, whilst populationsHB-5, HB-8, HB-9, HB-10, HB-11, HB-12, HB-13, and HB-14 expressed high level of resistance to tribenuron-methyl withresistance indices over 100. The proportion of moderate resistance level was about 9.09%, and that of high resistance wasabout 36.36%.

Skeletal muscle satellite cells are stem cells that are known for their multipotency and ability to proliferate in vitro. However, primary skeletal muscle satellite cells have limited proliferative capacity in vitro, which hinders their study in poultry skeletal muscle. The emergence of immortalization techniques for cells has provided a useful tool to overcome this limitation and explore the functions of skeletal muscle satellite cells. In this study, we achieved the immortalization of chicken skeletal muscle satellite cells by transducing primary cells with TERT (Telomerase reverse transcriptase) amplified from chicken (chTERT) using a lentiviral vector through reconstitution of telomerase activity. The cells successfully bypassed replicative senescence but did not achieve true immortalization. Preliminary functional characterization of the established cell line revealed that the proliferative characteristics and cell cycle profile of the immortalized chicken skeletal muscle satellite cell lines (ICMS) were similar to those of chicken primary muscle satellite cells (CPMSCs). Serum dependency analysis and soft agar assays indicated that ICMS did not undergo malignant transformation. Induced differentiation results demonstrated that ICMS retained their capacity for differentiation. The cell lines established in this study provide an important basis for the establishment of immortalized poultry cell lines and a cell model for the study of poultry skeletal muscle-related functional genes.