Supervisor(s): Ministry of Agriculture Sponsor(s): Chinese Academy of Agricultural Sciences；Chinese Association of Agricultural Science Societies CN：11-1328/S
Scientia Agricultura Sinica, the 1st in Comprehensive Agricultural Science, is supervised by Ministry of Agriculture of PRC, and sponsored by Chinese Academy of Agricultural Sciences; Chinese Association of Agricultural Science Societies. Scientia Agricultura Sinica, launched in 1960, is a leading peer-reviewed and mufti-disciplinary journal and published semi-monthly in Chinese with English title, abstract, figures, tables and references. It aims to publish those papers that are influential and will significantly advance scientific understanding in agriculture fields worldwide. The scope covers Crop Genetics, Breeding, Germplasm Resources; Physiology, Biochemistry, Cultivation, Tillage Plant Protection; Soil & Fertilization, Agro-Ecology & Environment, Bio-energy; Animal Science, Veterinary Science, Agricultural Information Science; Food Science; Agricultural Economics and Management; Agricultural Sustainability.
The journal is included in JST, CA and CSCD.
Editor-in-Chief Wan Jianmin Associate Editor-in-Chief Zou Ruicang Tang HuaJun Wu Kongming Guo YuYuan Geng Xu Sun Tan Executive Editor Lu Wenru
[Objective] The objective of this study is to investigate the role of BmRelish, a NF-κB-like transcriptional factor in immune response against infection of
Bombyx mori nucleopolyhedrovirus (BmNPV), and to screen and analyze the potential antiviral cytokines to better understand the antiviral immunity in silkworm (
B. mori). [Method] The generation of BmRelish active form (BmRelish
act) from full-length BmRelish (BmRelish-FL) in BmE cells after BmNPV infection was examined by Western blotting, the relative level of viral DNA in BmRelish
act-expressing cells was evaluated by quantitative PCR, and the amount of EGFP-positive cells was compared with control cells which did not express BmRelish
act after infection with EGFP-labeled BmNPV (BmNPV-EGFP) to investigate whether BmRelish participated in antiviral immunity. Naive cells were then incubated with supernatant medium of BmRelish
act-expressing cells in Transwell co-culture system followed by BmNPV infection, and the relative level of viral DNA in those cells was evaluated to determine whether antiviral cytokines were produced and secreted from BmRelish
act-expressing cells. Next, the supernatant medium of BmRelish
act-expressing cells was fractionated by ultrafiltration, and the filtrate and retentate fractions were incubated with naive cells respectively, the relative level of viral DNA in those cells was then evaluated to estimate the molecular mass of antiviral cytokines. This assay was also performed with heat-treated filtrate and retentate to determine the biological properties of antiviral cytokines. Finally, the supernatant medium of BmRelish
act-expressing cells was analyzed by LC-MS/MS. [Result] After BmNPV infection, BmRelish-FL was partially processed into its active form (BmRelish
act), and the relative level of viral DNA as well as the amount of BmNPV-EGFP positive cells in BmRelish
act-expressing cells was significantly lower than those in control cells. Incubation with supernatant medium of BmRelish
act-expressing cells also led to a remarkable decrease in the relative level of viral DNA in naive cells after BmNPV infection. Incubation with filtrate fractions from the supernatant medium of BmRelish
act-expressing cells fractionated by centrifugal filters with cut-off size of 100 kD and 3 kD maintained the antiviral activity, while that with retentate fractions did not. The antiviral activity could be removed by heating. A total of 67 peptides consisting of 9–45 amino acids and derived from 32 proteins were identified by LC-MS/MS from the filtrate fraction of supernatant medium. Those proteins all have molecular mass > 3 kD and 9 of them contain signal peptide. [Conclusion] BmRelish is activated in response to BmNPV infection and participates in antiviral immunity by promoting the production of antiviral cytokines, which are secreted into the supernatant medium and enhance the anti-BmNPV immunity of naive cells. Those anti-BmNPV cytokines are small peptides with molecular mass < 3 kD cleaved from larger proteins.
[Objective] Porcine reproductive and respiratory syndrome (PRRS), commonly known as “blue ear disease”, is a highly fatal infectious disease with porcine reproductive and respiratory syndrome virus (PRRSV) being the causative pathogen. PRRSV causes major economic losses in the pork industry world-wide. The genetic variability of PRRSV is high and an ideal vaccine to prevent the occurrence of this disease is not available. Cluster of differentiation 163 (CD163) is the important receptor for the entry of PRRSV into the porcine alveolar macrophage (PAM) cells. The aim of this study was to generate CD163 gene edited Large White pigs by using the CRISPR/Cas9 and somatic cell nuclear transfer (SCNT) techniques. [Method] CRISPR/Cas9 vector was constructed for editing the exon 7 of the porcine CD163 gene. The constructed vectors were transfected into pig fetal fibroblasts to obtain gene edited positive cell colonies. The CD163 gene edited fibroblasts and in vitro matured porcine oocytes were employed as nuclear donors and nuclear receptors respectively to obtain reconstructed embryos. For obtaining CD163 gene edited pigs the reconstructed embryos were transferred into recipient sows and performing the subsequent propagation experiment. [Result] The designed gRNA could effectively recognize the intended site. Genotyping analysis of cloned cell showed that 21 colonies had mutations in the CD163 gene, of which 14 colonies had either a monoallelic mutation or a biallelic heterozygous mutation, and 7 colonies had a biallelic homozygous mutation. Through SCNT, we successfully obtained CD163 biallelic edited Large White pigs. Successful breeding allowed us to obtain F
1 generation CD163 gene edited piglets, and they were all in good health. It was anticipated that more F
1 piglets would be produced soon. [Conclusion] The CD163 biallelic edited Large White pigs that did not harbor a drug resistant gene in their genome were produced and they could thus safely and quickly serve as a gene donor for breeding of PRRSV resistant pigs.
[Objective] The characteristics of soil erosion and nitrogen loss in sloping cropland of purple soil during maize (
Zea mays L.) growth stage under the rainstorm were investigated to provide a theoretical basis for the prediction and effective prevention of nitrogen loss. [Method] Simulated rainfall combined with runoff plot experiments were employed during maize seedling stage (1th May), elongation stage (26th May), tasseling stage (27th June) and maturity stage (4th August). According to the feature of the stormy summer months in the purple soil region of Sichuan Province, the characteristics of nitrogen loss in surface runoff, interflow, and sediment were studied during maize growth stage under rainfall intensity of 1.5 mm·min
−1 and the slope gradient of 15°. [Result] (1) The rate of surface runoff and sediment yield increased with the increasing rainfall duration during maize growth stage, which were the highest within seedling stage, and the lowest within tasseling stage, but the rates of interflow within tasseling stage and maturity stage were the highest and lowest, respectively. (2) The rate of nitrogen loss in surface runoff increased with the increasing rainfall duration and became stable after the rainfall duration of 36 min. The average total nitrogen and dissolved total nitrogen were up to 5.24 mg·m
−2·min
−1 and 4.74 mg·m
−2·min
−1 in seedling stage, respectively. The rate of nitrate nitrogen reached stable after the rainfall duration of 30 min, and the rate of ammonium nitrogen showed volatility with rainfall duration. The rates of nitrate nitrogen and ammonium nitrogen were up to 3.90 mg·m
−2·min
−1 and 0.14 mg·m
−2·min
−1 in elongation stage, respectively. The regression relationships of total nitrogen, dissolved total nitrogen and nitrate nitrogen with surface runoff during maize growth stage were extremely significant. (3) The rate of nitrogen loss in the interflow increased slowly with increasing the rainfall duration. The rates of dissolved total nitrogen and nitrate nitrogen showed the same trend with nitrogen loss within seedling stage, elongation stage and maturity stage, while the rate of ammonium nitrogen showed volatility with time. The rates of total nitrogen, dissolved total nitrogen, nitrate nitrogen and ammonium nitrogen were up to 25.04, 20.34, 16.20 and 0.22 mg·m
−2·min
−1 within elongation stage, respectively. The regression relationships of total nitrogen, dissolved total nitrogen and nitrate nitrogen with interflow during maize growth stage were significant, and the slope of linear relationship was the biggest within elongation stage. (4) The rate of nitrogen loss in sediment yield increased with the increasing rainfall duration, but the increase was the highest in seedling stage, which was up to 0.92 mg·m
−2·min
−1. The regression relationship between nitrogen loss and sediment yield during maize growth stage was extremely significant. (5) The forms of nitrogen loss in the surface runoff reached the highest in seedling stage and elongation stage. The nitrogen loss in the interflow reached maximum in elongation stage and tasseling stage. The nitrogen loss in sediment yield reached the highest in seedling stage. Interflow was the main source for nitrogen loss and accounted 64.07%–83.39% of the total nitrogen loss. Dissolved total nitrogen was the main form of nitrogen loss in surface runoff and interflow, and nitrate nitrogen was the main form. [Conclusion] Under the rainfall intensity of 1.5 mm·min
−1, the nitrogen losses in surface runoff and interflow were the highest within seedling stage and elongation stage, respectively. The dissolved total nitrogen and nitrate nitrogen were the highest in elongation stage, which could easily lead to the eutrophication in waters. Thus, it is necessary to control surface runoff in seedling stage and interflow in elongation stage to reduce nitrogen loss in the purple soil region.
Abstract: [Objective] Remote sensing has a strong superiority in crop planting area acquisition. It is critical to design an efficient hierarchical indicator in a stratified sampling investigation. Traditional method neglects the classifying error of the classification results, which reduces the sampling efficiency. Therefore, a new hierarchical indicator (
S
correct) that can correct the error area is presented in this paper, which is in favor of raising the efficiency of the sampling survey. [Method] The yield of winter wheat in Tongzhou and Daxing district of Beijing was as a study object. The data source was GF-1 imagery (resolution: 16 m, phase: 2015-04-04) obtained in winter wheat growing season. This paper designed the
S
correct which was based on an algorithm involved the error of omission and the error of commission at pixel scale. This indicator summed all pixels’ correct scale in a sampling unit to correct the area scale indicator (
S). A certain plan was devised for multiple sampling by using
S
correct and the area scale indicator (
S). This plan constructed regular square grids (size: 90–300 m) as the sampling frames, set the number of layers, determined the hierarchical boundary method and the allocation method for sample capacity, etc. In order to testify the validity of
S
correct, this paper analyzed the correlation between this indicator and true value, estimated the total winter wheat area by multiple sampling, after that, compared
S
correct with
S in sampling variance, average relative error
value, etc. The typical corrected regions for pixel with error were selected to compare and analyze for verifying the effectiveness at pixel scale. [Result] (1) By comparing and analyzing the typical corrected regions, the error distribution could accord with the actual circumstance for both the error of omission and the error of commission. This indicator could correct error pixel. With the sizes of the sampling unit,
S
correct was better than
S in the correlation, and the value was greater than 0.7, which could ensure a high and stable correlation with the truth value. The validity of
S
correct was verified by experiments. (2)
S
correct was better than
S in the stability, accuracy and
CV value. Its total variance was 1.70 × 10
13–2.41 × 10
13, and the total variance obtained by using
S was 2.05 × 10
13–3.11 × 10
13. Its
was 4.21%–5.00%. The
obtained by using
S was 4.87%–5.98%. Therefore, nearly 1% could be enhanced stability in accuracy. Besides,
S
correct could reduce
CV value nearly 0.8%. [Conclusion] The effectiveness and advantages of
S
correct were proved by the experimental results. The indicator could improve the accuracy of sampling and the stability of inference in a certain extent.
The genetically engineered (GE) crop breeding or the widely accepted ‘precise breeding’ are the techniques based on the human desire to modify crop traits with precise characteristics of known inserted DNA and protein sequences, anticipated function, and defined insertion sites in the genome of a given species. The acreage of GE crops reached 1.851 billion hectares all over the world in 2016, which was increased by almost 100 folds compared with that in 1996, the year for the starting of GE crop commercialization. This indicates that the genetic engineering is the fastest developing technology in the history of agriculture, which has provided significant economic, social, and environmental benefits to the world. During the development and commercialization of GE crops in recent three decades, huge amount of scientific data and experiences have also been accumulated regarding their risk assessment and regulation. However, many unscientific burdens still exist, which needs to be further reformed. In particular, the rapid development of new products obtained via the techniques such as genome editing has also raised the questions on how to evaluate and regulate them. Theoretically and practically speaking, genetic engineering, as a technique, has posed no intrinsic unique or incremental risks compared with the traditional breeding techniques. From scientific point of view, it is common that the GE crops have been inadequate- or over-regulated in the recent 30 years. In fact, so far, the risk-based classification and regulation on GE crops has not been fully implemented. Not only the European ‘Process-based’ regulation should be eliminated, but also the US ‘Product-based’ regulation should be further improved. Currently, the innovation and reformation in this field based on science have become a common trend internationally. In this paper, some scientific issues associated with environmental and food safety of GE crops are addressed, including what is the proper object for risk assessment (transformed event, variety, or species?), the effect of Bt protein on target and non-target organisms, the potential impact of transgene flow, the toxin, allergenicity, compositional change and un-expected effect, and the marker genes and plant pathogen derived DNA sequences in the GE cops. All of these were discussed based on the current scientific knowledge, by which the major focus points in the risk assessment were discussed. Finally, a regulatory framework based on risk classification, which integrally determined by the species that either used as donor or recipient, the genes that confer specific traits and the environment into which the GE crop introduced, was proposed. The possible products belonging to the category of low, mediate or high risk were listed individually. In terms of species, whether the donor or recipient of a transgene has a long history of safe use, does it contain any known toxins, allergens or anti-nutrients should be carefully assayed. Considering the source of transgene, the GE crops can be classified into three categories of intragenesis, cisgenesis, and transgenesis. The intragenesis is the gene modifications or transfers within the same species,
e.g., the most crops derived from genome editing exhibiting gene silence, knock-out, modification or insertion with no or very low risk. The cisgenesis is the gene transfers between sexual compatible species that may pose low risk. While the transgenesis transfer genes between sexual incompatible species that may present mediate or higher risk. In terms of environmental safety, the risk assessment should be focused on whether there is any sexual compatible wild species or weed existed in the environment in which the GE crops are going to be released, whether the crossing and backcrossing between crop-to-wild would cause gene introgression that may lead to the selective competitiveness of the hybrids, whether the region in which the GE crops are intending to release is the origin center of a given species,
etc. All of these issues have to be considered as major focuses in the risk assessment and regulation of GE crops.
