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 purpose of this study is to clone and express
Schistosoma japonicum embryonic lethal abnormal vision like 1 (
SjELAV-like 1) gene and analyze the expression statuses at different stages and under different infected conditions as well as its distribution in the worms of
S. japonicum. We also intend to explore the effect of
SjELAV-like 1 on the morphology and reproductive development of
S. japonicum. [Method] The RACE technique was used to amplify the 5′/3′ end of the
SjELAV-like 1 gene, and the obtained sequence was submitted to NCBI, with the GeneBank accession number: MG515727. The recombinant plasmid pET28-
SjELAV-like 1 was constructed and expressed in
E. coli BL21 through IPTG induction and then the products were collected at different time. The SDS-PAGE was used for protein analysis. His-tag nickel column affinity chromatography was used to purify the recombinant protein. The purified recombinant protein was used to immunize mouse to obtain the polyclonal antibody, which was used to analyze the immunogenicity of the recombinant protein by western blotting and detect the distribution of SjELAV-like 1 protein in
S. japonicum by indirect immunofluorescence assay. The mice infected by cercaria of
S. japonicum in the abdomen were used to collect mixture and the females and males separated by paired worms at different stages. The mice infected by cercaria escaped from the single nails were used to collect the single-sex worms on the 25th day. The expression level of
SjELAV-like 1 was detected by quantitative real-time PCR (qRT-PCR). The gene silencing was performed by tail vein injection of small interference RNA (siRNA) in infected mice. The long-term RNA interference (RNAi) assay was performed to analyze the effects of
SjELAV-like 1 gene silencing on the spawning and egg hatching of females. The tegument structure and reproductive organs of the females and males of
S. japonicum were observed by scanning electron microscopy and transmission electron microscopy after RNAi. [Result] In this study, a 1 797-bp sequence of
SjELAV-like 1 was obtained, whose coding region was 1 533 bp, encoding 510 amino acids. The expression of the recombinant plasmid reached the maximum after 4 h of IPTG induction and it mainly existed in the form of inclusion bodies. High quality polyclonal antibody was obtained against the purified protein. SjELAV-like 1 protein was mainly located in the tegument of the worms.
SjELAV-like 1 was expressed at all stages of
S. japonicum and the expression was stable in males but gradually became less in females as the maturing of the worms. The expression of
SjELAV-like 1 was higher in development impaired females compared with the normal worms. In the RNAi assay, the long-term interference group showed that the liver egg burden, liver egg burden by per female and egg hatching rate in interference group were reduced by 58.27% (
P < 0.05), 40.59% (
P < 0.01) and 74.58% (
P < 0.01) compared with NC group, respectively. The electron microscopy observation found that the tegument structure of the worms in interference group was obviously different from that in NC group. The surface bubble adhering to the surface of males disappeared, the three-dimensional fold ridge collapsed, the funicular surface ridge arranged loosely and the network structure of the body wall disappeared. The body surface gap increased and the spines on the body wall of the female were dull. The number of spermatocyte in the males was decreased and the intracellular chromatin was reduced, while the cells were swollen and the intercellular space was widen. In females of
S. japonicum, the vitelline globules in vitelline cells were decreased, in which the vitelline droplets were also reduced, the endoplasmic reticulum was swollen and the cortical particles were scattered. [Conclusion] Part sequence of
SjELAV-like 1 was successfully cloned and expressed, which was robustly expressed in development impaired females.
SjELAV-like 1 was mainly expressed in the tegument of
S. japonicum.
SjELAV-like 1 silencing led to the decrease of liver egg burden, liver egg burden by per female and egg hatching rate.
SjELAV-like 1 silencing also altered the tegument structure of the worms and hindered its development of reproductive glands. These all suggested that
SjELAV-like 1 played an important role in the development of the reproduction of
S. japonicum.
[Objective] The objective of this study is to analyze the relationship between the spray volume in rice fields and retention on rice plants, to understand the mechanism affecting the control effect of pesticide unit dose, and to provide a basis for the scientific use of pesticides. [Method] The liquid retention on unit area of rice was measured under spraying conditions, and the change of the liquid retention indicated the point of run-off and maximum retention of the liquid on rice leaves. The surface tension of the liquid was measured by the method according to the GB/T 5549-2010, and the critical micelle concentration of the surfactant solution was determined by using the law of the surface tension varying with the concentration of the surfactant. The Zisman method was used to measure the critical surface tension of rice leaves. The key factors affecting the leaf capacity of rice leaves were analyzed. By simulating chlorantraniliprole control of rice leaf roller (
Cnaphalocrocis medinalis), pymetrozine and chlorpyrifos control of brown planthopper (
Nilaparvata lugens) in a spray tower, the relationship between spray volume and droplet density and the effect of pesticide unit dosage on control effect against pests were also investigated. [Result] With the increase of the spray volume, the liquid retention of rice leaves increased. After reaching the maximum value, the liquid began to lose and then it decreased to a stable value and no longer changed. The final liquid retention was only 50% of the maximum value. The critical surface tension of the tested rice leaves was 29.90–31.22 mN·m
−1, which meant that the tested surface was a low-energy surface. The surface tension of clear water was 71.8 mN·m
−1, which was greater than the critical surface tension of the tested surface. The surface tension of tested rice leaves limited the liquid retention of the leaves. With the additives TX-10 and Silwet-408, the surface tension of the liquid was less than the critical surface tension of rice, which increased the liquid retention of the rice leaves. When the auxiliary agent reached the critical micelle concentration, TX-10 and Silwet-408 provided the best results. The amount of liquid spray affected the density of spray droplets, thus affecting the control effect of pesticide unit dose. When the droplet volume median diameter was 200 μm, the liquid droplet volume of 150 L·hm
−2 resulted in the droplet density of 10 drops/cm
2. The control effects of three effective doses 20, 25 and 30 g of chlorantraniliprole against
C. medinalis were less than 60%. The liquid droplet volume of 450 L·hm
−2 had the droplet density less than 40 drops/cm
2. The control effects of three effective doses against
C. medinalis were 56.92%, 62.86% and 65.07%, respectively. The liquid droplet volume of 900 L·hm
−2 had the droplet density of 82 drops/cm
2, and the three effective doses of chlorantraniliprole had the best control effect on
C. medinalis, which was over 70%. Reducing the droplet volume median diameter and increasing the amount of droplets of unit volume of liquid could reduce the amount of liquid spray. When the diameter of droplets was 75 μm and the liquid volume was 450 L·hm
−2, the droplet density was 140 drops/cm
2 and the control effect of chlorantraniliprole against
C. medinalis had no significant difference with that in the case of 200 μm droplet diameter and 900 L·hm
−2 liquid volume. Because of the barrier of rice canopy, the droplets under the canopy was very few when spraying on the longitudinal surface of rice. When the droplet volume median diameter was 200 μm and the spray liquid volume was 900 L·hm
−2 or the droplet volume median diameter was 75 μm and the spray liquid volume was 450 L·hm
−2, the amount of droplets under the canopy was less than 20 drops/cm
2, and the pesticides had poor control effect on
N. lugens. Under the canopy spray, pesticides were sprayed directly on the infestation sites of
N. lugens, and the control effects of the pymetrozine and chlorpyrifos unit doses on
N. lugens were significantly improved. [Conclusion] The amount of liquid used affects the amount of pesticides deposited on rice plants and the density of droplets per unit area of rice, thus affecting the control effect of pesticide unit dose on pests. When the liquid volume was 450 L·hm
−2 (droplet diameter 75 μm) or 900 L·hm
−2 (droplet diameter 200 μm), the canopy was evenly sprayed up and down in rice fields, which ensured that the liquid retention on rice plant was within the range of the point of run-off and had a sufficient density of droplets, and the control effect of pesticide against pests was good.
Climate change will change the growth environment of crops, thereby affecting crop yield and quality. The effects of climate change on the yield formation of rice, one of the most important grain crops, were reported extensively, but there were few studies on rice quality, which bore equal importance as yield in terms of rice production safety. After a brief introduction of the experimental platform, this paper summarized the research progress of the impact of climate change on rice quality. The quality traits were classified into processing, appearance, cooking/eating, nutritional and feeding quality. The climate change included elevated atmospheric CO
2 concentration, elevated tropospheric O
3 concentration, and higher temperature. This paper focused on the interactions between atmospheric composition change and high temperature on rice quality. Previous studies showed many uncertainties about the impact of climate change on rice quality, but some important trends were also found. Unfortunately, most of these trends indicated unfavorable changes in rice quality. The rice growing in high CO
2 concentration, high O
3 concentration or high temperature environment exhibited an increase in grain chalkiness and a higher percentage of broken grains during milling process. The concentrations of protein and several micronutrients in rice grains decreased with high CO
2 concentration, but the palatability was improved. Both the eating quality of rice grain and feeding quality of rice straw showed a trend of deterioration when plants were growing under ozone stress. At present, the understandings in this area are obtained mostly from the impact of single climatic factor, but the interaction between CO
2 and temperature or O
3 was observed in a few studies. In addition, the responses of rice quality traits to climate change might also be affected by fumigation methods, genotypes and fertilizer application. In future, the experimental platforms of different scales should be employed to verify the existing trends; more efforts should devote to evaluate the interactions between climate change factors and other factors and to reveal the mechanisms of these interactions; and all related research should aim at the successful development of rice production technology that can truly adapt to the future climate change.
[Objective] This study was conducted to examine the effect of elevated atmospheric carbon dioxide (CO
2) concentration and temperature on nitrous oxide (N
2O) emission from annual rice–wheat rotation systems, so as to gain an insight into the response of N
2O emission fluxes to climate change. [Method] An in-situ field experiment was established in annual rice–winter wheat rotation systems under a T-FACE platform, consisting of four treatments under different CO
2 concentration and temperature levels (ambient CO
2 + ambient temperature, ambient; 500 μmol·mol
−1 CO
2 + ambient temperature, C; ambient CO
2 + temperature increased by 2 °C, T; 500 μmol·mol
−1 CO
2 + temperature increased by 2 °C, C + T) during 2012–2015. The fluxes of N
2O from rice–wheat rotation fields were measured using static opaque chamber-gas chromatograph method. [Result] (1) On an average of two rice seasons, elevated atmospheric CO
2 concentration significantly increased the biomass and yield of rice by 9.7% and 5.6%, respectively, and those increments of wheat were 11.3% and 5.7% over the three wheat seasons (
P < 0.05), respectively. Elevated temperature significantly reduced the biomass and yield of rice by 21.1% and 31.6%, and those reductions for wheat were 18.0% and 17.7%, respectively. The combination of elevated CO
2 and temperature significantly reduced the biomass and yield of rice by 13.5% (
P < 0.05) and 26.0%, and those reductions for wheat were 8.7% and 10.3% (
P < 0.05), respectively. (2) Either elevated CO
2 concentration or temperature did not affect the seasonal patterns of N
2O emission from rice–wheat rotation system. Elevated CO
2 concentration increased N
2O emission in rice and wheat seasons by 15.2% and 39.9%, respectively. Elevated temperature did not affect N
2O emission in rice season, but significantly increased N
2O emission in wheat season by 20.5% (
P < 0.05). Despite of a considerable interannual variation, N
2O emission tended to be increased by the combined effect of elevated CO
2 concentration and temperature in rice season. The emission of N
2O in wheat season was significantly increased by 46.0% under the condition of C + T treatment. (3) The cumulative N
2O emission in wheat was positively correlated with underground biomass of wheat and ΔSOC. (4) Elevated atmospheric CO
2 concentration, elevated temperature, and their combination increased GHGI of rice–wheat rotation field by 29.1%, 66.3%, and 81.8%, respectively. [Conclusion] All of these results showed that both elevated CO
2 concentration and temperature had strong impact on the emission of N
2O in rice–wheat rotation field. Elevated CO
2 concentration significantly increased the emission of N
2O in both rice and wheat seasons. Elevated temperature significantly increased N
2O emission in wheat season, but no significant change was observed in rice season. Elevated CO
2 concentration increased N
2O-derived GHGI from rice–wheat rotation field, but it was not significantly different. Elevated temperature and the interaction between elevated CO
2 concentration and temperature significantly increased GHGI. The effect of different applied treatments on N
2O-derived GHGI from rice–wheat rotation field was in the descending order of C + T > T > C. It was suggested from this study that to ensure present crop supply level under the condition of high atmospheric CO
2 concentration and temperature would likely exacerbate climate change by increasing N
2O emission.
[Objective] The cysteine-rich receptor kinase (CRK) is one of the largest family of receptor-like kinases in plants, and plays important roles in plant growth and development, hormone signal transduction and stress tolerance. So far, few cotton
CRK genes have been reported.
In silico identification, bioinformatics and expression analysis of
CRK family genes in upland cotton on whole genome level lays the foundation for in-depth study and utilization of
CRK family genes in cotton. [Method] The conserved stress-antifung domain sequence downloaded from the Pfam database was used as query sequence to search the
Gossypium hirsutum (cv. TM-1) genome database to identify cotton CRKs by using BLASTp program; the theoretical isoelectric point and molecular weight, signal peptide, transmembrane domain, subcellular localization of cotton CRK proteins were predicted applying Compute
pI/Mw, Signal P, TMHMM Server V2.0, Wo LF POSRT online program respectively; amino acid sequence alignment of CRK proteins in cotton and
Arabidopsis thaliana was performed using Clustal X1.8 software. The phylogenetic relationships of cotton and
Arabidopsis CRK proteins were analyzed with MEGA5.0; the chromosome location, gene structure and conserved domain were visualized with TBtools. The promoter sequences of cotton CRK genes were
In silico analyzed by searching Plant CARE database; the phosphorylation sites were predicted with Plant Phos. The RNA-Seq data were downloaded from the NCBI database, the TPM values were calculated using transcriptome quantification tool Kallisto, the heatmap of CRK gene expression was drawn with online tools Morpheus. [Result] There were 70
CRK genes in upland cotton genome distributed on 14 chromosomes, 52 genes (74. 3% of the total) were intensively distributed in clusters on A6/D6, A9/D9 and A10/D10 chromosomes characterized by collinear relationships between A/D chromosomes. These
CRK genes encode proteins containing 302–901 amino acids, 58 proteins (82.9%) had a transmembrane domain, mainly located in the chloroplasts, plasmalemma and extracellular. The phosphorylation site prediction results showed that cotton and
Arabidopsis CRK shared five consensus phosphorylation sites, including three serine phosphorylation motifs and two threonine phosphorylation motifs. The promoter regions of 65 cotton CRK genes (accounted for 92.9%) contained at least one stress hormone response element, and 69 (98.6%) genes contained at least one biotic or abiotic stress response element. The RNA-Seq data analyses showed that the tissue expression patterns of
CRKs could be divided into three types, and that the expression of some
CRK genes were altered in response to salt, drought, cold, heat stress and inoculation with Verticillium dahliae Kleb. Gh CRK25 was predominantly expressed in roots, stems, leaves, and ovules, but barely accumulated in fibers. ABA, GA
3, SA, PEG-6000, NaCl, and
Verticillium dahliae Vd991 could stimulate rapid up-regulation of GhCRK25 expression. The GhCRK25-silenced cotton by using virus induced gene silencing technology (VIGS) showed increased susceptibility to
Verticillium dahliae Vd991. [Conclusion] There are 70 members of
CRK family gene in the upland cotton genome. They have conserved gene structure and functional domain, diverse tissue expression characteristics; most of cotton
CRK genes are responsive to hormone and stress stimulus.
