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 was to evaluate the effect of the milk replacer on the intestinal development, the flora diversity and the relative expression of glucose transporter gene of Yimeng black goat lambs in order to provide theoretical basis for the cultivation of early stage Yimeng black goat lambs. [Method] A total of 36 twin-born Yimeng black goat lambs were randomly divided into 2 groups, each with 6 replicates and each with 3 replicate lambs. The lambs in the control group (group I) were fed with breast milk for 75 days, while the lambs in the experimental group (group II) were weaned on the 10th day and fed with milk replacer thereafter. The weights of duodenum, jejunum, ileum as well as live body of the lambs in the two groups were recorded on the 10th, 15th, 25th, 45th and 75th day, and meanwhile, the small intestinal contents and mucous tissue samples were collected. The colonization of small intestinal flora and the expression of glucose transporter (
SGLT-1,
GLUT-2) gene mRNA were analyzed by the PCR-DGGE of 16S rD NA and real-time fluorescence quantitative PCR, respectively. [Result] The results showed that the average daily gain and the weight of jejunum and ileum of the lambs in group II on the 45th day were significantly higher than those in group I (
P < 0.05), while on the 75th day, the average daily gain and ileum weight of the lambs in group II were highly significantly higher than those in group I (
P < 0.01). The flora distribution difference between group I and group II was significant in the duodenum on the 45th and 75th days, in the jejunum on the 15th day and in the ileum on the 10th day. The flora diversity in the ileum was higher than that in the jejunum and duodenum, and the microbiota diversity in the jejunum was higher than that in the duodenum. The bacterium lacticum dissolving starch and prevotella were dominant bacteria in the whole intestinal tract of groups I and II. The number of probiotics in group I decreased with the growth of age, while an opposite dynamic was found in group II. The expression of SGLT-1 and GLUT-2 genes in the group II was the lowest on the 10th day, but their expression increased on the 25th day, and meanwhile the two genes took on different expression profiles in different intestinal segments. The fluctuation of expression level of SGLT-1 was the highest and lowest in the jejunum and duodenum, respectively, while that of GLUT-2 was the biggest and lowest in the duodenum and ileum, respectively. [Conclusion] In conclusion, feeding milk replacer could promote early colonization of probiotics in the jejunum and ileum of early weaned Yimeng black goat lambs on the 25th day and the glucose absorption and transport could be changed by regulating glucose transporter gene expression, which further affected later development of intestinal tissue and the growth of the lambs.
[Objective] Field experiments were conducted to explore the activities of key enzymes in wheat (
Triticum aestivum L.) root NADP-dehydrogenase system and their relationships with root vigor and grain yield under the condition of reducing nitrogen fertilization in the typical field on the Huang-Huai Plain, in China. [Method] The split block design was employed with two semi-winterness wheat cultivars, Aikang 58 and Zhoumai 27, and six nitrogen fertilizer application rates of 0 (N0), 135 (N1), 157.5 (N2), 180 (N3), 202.5 (N4), and 225 kg N·hm
−2 (N5). The activities of NADP-ICDH, NADP-ME and (G6PDH + 6PGDH) and root vigor with improved TTC method were measured prior to wintering, and at re-growing, jointing, heading, grain-filling and late dough stages. Then, the relationships between activity of these key enzymes with root vigor at different growth stages and grain yield were analyzed. [Result] The results showed that the dynamics of root vigor had a “high–low–high–low” trend during the whole wheat growing period. The activities of NADP-ICDH, NADP-ME and (G6PDH + 6PGDH) were all increased at first and then decreased. However, the difference in activities of these key enzymes was not significant at 5% probability level after grain-filling stage. Before jointing stage, the activities of key enzymes in the NADP-dehydrogenase system were greater in N0 than those in nitrogen application treatments N1–N5. However, from jointing to heading stage, the activities of key enzymes and root vigor under the treatments from N1 to N5 were significantly higher than those under N0. Further analysis pointed out that both the activity of NADP-dehydrogenases and root vigor were decreased with the decrease of nitrogen fertilization rate. Compared with N5, the decrease both in the activities of NADP-ICDH, NADP-ME and (G6PDH + 6PGDH), and in root vigor under N4 was the least. Nitrogen application rate significantly affected wheat grain yield and its components. Compared with N0, the wheat spikes per unit area and grains per spike were significantly increased under nitrogen treatments N1–N5. The average grain yields in the two experimental years indicated that the yield under N5 was the highest, 9 238.02 kg·hm
−2. Compared with N5, the wheat grain yield under N4 was only decreased by 0.3%, while those under treatments of N3–N0 were decreased significantly. The statistical analysis showed that there was significant or extremely significant positive correlation between the activities of NADP-ICDH, NADP-ME, and (G6PDH + 6PGDH) at different growth stages. There was significant or extremely significant positive correlation between the activity of key enzymes in root NADP-dehydrogenase system with root vigor in middle and late wheat growing periods. Grain yield had significant or extremely significant positive correlation with root vigor, activities of NADP-ICDH, NADP-ME, and (G6PDH + 6PGDH). The path analysis further showed that the activities of NADP-ICDH, NADP-ME and (G6PDH + 6PGDH) at both jointing and heading stages had greater positive effects on grain yield in two years. The direct effect of root vigor at heading stage on yield was smaller, but the indirect positive effect of root vigor by means of increasing activity of NADP-ME and (G6PDH + 6PGDH) on grain yield was significant or extremely significant. [Conclusion] Under the experimental conditions in this study, reducing nitrogen application rate from N5 to N4 can be optimum at present in wheat field in the Huang-Huai Plain, considering the dynamics of activity of key enzymes in root NADP-dehydrogenase system, root vigor, and grain yield. NADP-ICDH, NADP-ME and (G6PDH + 6PGDH) were closely related to the root vigor determined with the improved TTC method. Particularly, NADP-ME and (G6PDH + 6PGDH) were the most important enzymes. It was concluded that wheat root vigor could be improved by high expression of NADP-ME and (G6PDH + 6PGDH) in roots, which could be achieved by means of molecular breeding and effective cultivation operations.
[Objective] In order to provide a scientific basis for nutrient regulation of
Rosa roxburghii culture in calcareous yellow soil of Guizhou Karst region, the effect of exogenous citric acid on the nutrient activation of calcareous yellow soil was analyzed and the effect of exogenous citric acid on nutrient absorption and growth of
R. roxburghii in calcareous yellow soil was explored. [Method] Taking calcareous yellow soil and 'Guinong 5’
R. roxburghii seedlings as materials, three treatments of citric acid 40 mg, 80 mg and 120 mg per 1 000 g of dry soil were set up with the pot experiment method. The available nutrients, microbial numbers, enzyme activity and low molecular organic acids of treated calcareous yellow soil, and the effect on the parameters for nutrient uptake and growth of
R. roxburghii seedlings were measured. [Result] The application of exogenous citric acid to calcareous yellow soil showed that the pH of soil was obviously decreased, and the contents of available N, P, K, Ca, Fe, Zn and B were significantly increased. Among the three treatments, the contents of available P, K, Ca, and B in the soil were the highest in 80 mg·kg
−1 citric acid treatment and the effective contents of N, Fe and Zn in soil were the highest in 120 mg·kg
−1 citric acid treatment, but the contents of Mn and Cu in soil were significantly decreased and the content of Mg had almost no variation. The total number of bacteria and the numbers of phosphorus-solubilizing bacteria and potassium-solubilizing bacteria in soils increased with the increase of applied citric acid amount, and the numbers of fungi and actinomycetes were decreased. The numbers of phosphorus-solubilizing bacteria and potassium-dissolving bacteria were the largest under the treatment of 80 mg·kg
−1 citric acid. The activity of soil enzymes was significantly enhanced after application of exogenous citric acid in calcareous yellow soil and the activities of alkaline soil phosphatase, protease and sucrase were the highest in the treatment of 80 mg·kg
−1 citric acid; the activities of urease, nitrate reductase and the activity of iron reductase increased with the increase of citric acid application, and the diastase activity decreased with the increase of citric acid application. The contents of citric acid, tartaric acid, malic acid and acetic acid in the soil increased obviously after exogenous citric acid was applied to calcareous yellow soil, and the contents of tartaric acid, malic acid and total content of organic acid were the highest in treatment of 80 mg·kg
−1 citric acid; the contents of oxalic acid in all treatments were significantly lower than the control. After exogenous citric acid application to the calcareous yellow soil, the uptaking ratios of N, P, K, Ca, Mg, Fe, Zn, and B for
R. roxburghii seedlings were significantly increased, and the highest value was measured under 80 mg·kg
−1 citric acid concentration. The absorption of Cu for
R. roxburghii seedlings showed no significant changes with the increase of exogenous citric acid. Exogenous citric acid application significantly reduced the contents of citric acid and oxalic acid in roots of
R. roxburghii seedlings. The application increased the root activity and the contents of malic acid, tartaric acid, acetic acid and succinic acid, and also significantly increased the activities of nitrate reductase, alkaline phosphatase, secreted alkaline phosphatase, iron reductase and glutamine synthetase (
P < 0.05). Among three treatments, the root activity, activities of alkaline phosphatase, glutamine synthetase and exudative alkaline phosphatase were the strongest under the treatment of 80 mg·kg
−1 citric acid. The activities of nitrate reductase and iron reductase were increased with the increase of citric acid application. The growth, root development and root morphology of
R. roxburghii seedlings were significantly improved with all three exogenous citric acid treatments, and the largest biomass and plant height, root and shoot ratio, total root surface area, total volume and total root tip number were found in 80 mg·kg
−1 citric acid-treated seedlings, and the above indexes were significantly larger than those of the control (
P < 0.05). [Conclusion] The application of exogenous citric acid to calcareous yellow soil with pH higher than 8 could improve the soil ecological environment and activate soil nutrients. It could enhance the activities of various soil enzymes and increase the contents of tartaric acid, citric acid, malic acid and acetic acid and total bacteria, phosphorus-solubilizing bacteria and potassium-solubilizing bacteria, and promote the growth of
R. roxburghii seedling.
[Objective] Various types of embryo mutants and endosperm mutants in rice are excellent materials for dissecting embryo development and starch synthesis and regulation pathways. Through large scale screening and functional characterization of floury endosperm mutant with an embryo-lethal phenotype, serials of genes involved in embryo development and starch biosynthesis and regulation will be obtained, which will provide the theoretical guidance for the improvement of rice quality. [Method] In this study, we obtained a stably inherited floury and shrunken endosperm mutant
fse3 from a
japonica cultivar Ningjing 3 (NJ3), with an embryo-lethal phenotype. A hybrid F
2 population of
fse3 and 9311 was developed and the recessive individuals were selected to map the locus. The seeds were soaked in clear water at 30 °C for 24 h and then stained with TTC for 2 h at 35 °C in darkness to detect seed vigor. The structure of seed embryo which swelled at 30 °C for 9 h was observed with a stereomicroscope. The mature floury seeds were collected from the heterozygous mutant plants, and the physicochemical properties of mature seeds which were grinded to brown rice flour after being peeled were analyzed. The structure of mature starch granules was observed by a scanning electron microscope. Semi-thin sections were prepared to observe the starch granule structure of developing endosperm. The expression of genes involved in starch synthesis during grain filling was determined by qRT-PCR. Western-blot was used to detect the accumulation of proteins related to starch synthesis. [Result] The 1 000-grain weight, grain size, total starch content, apparent amylose content, and swelling power of starch in mature seeds of the mutant
fse3 all decreased compared with those of the wild type. The starch viscosity curve of
fse3 also had significant difference with that of the wild type. The peak paste viscosity, hot paste viscosity, cool paste viscosity, and break down viscosity of
fse3 were significantly higher than those of the wild type. The TTC staining showed that the embryo vitality decreased and the mutant embryo could not differentiate. By observing the structure of developing endosperm, we found that a large number of small and irregular single starch granules were produced in the endosperm of
fse3, and the development of compound starch grains was delayed. The cross section observation of mature seeds showed that the starch granules in
fse3 were loosely packed, with non-uniform sizes and large gap among granules. The
FSE3 locus was first mapped to a region on the long arm of chromosome 9 with 22 recessive individuals, and then was narrowed down to a 228 kb region which included 28 open reading frames (ORFs) by using 1 400 recessive individuals. In the process of grain filling, several genes related to starch synthesis showed up-regulated and down-regulated expression levels in the mutant. Immunoblotting showed that the protein accumulation of some amyloid synthase was reduced. [Conclusion]
FSE3 is a novel floury endosperm and embryo lethality related gene. It is mapped to a 228 kb region on chromosome 9, which plays an important role in the regulation of embryo and endosperm development of rice seed.
[Objective] Various viruses have been identified from sweet potato. Infections with different sweet potato viruses may result in different pathological symptoms of plants. The objective of this study is to investigate the microRNAs (miRNAs) in response to different pathogens from sweet potato viruses in sweet potato. [Method] Illumina RNA sequencing was performed to mine and identify the differentially expressed miRNAs among the samples with different infection pathological symptoms (yellowing and deformity, herpes, chlorotic and dwarf, and curl; samples were named Fj01, Fj02, Fj03 and 1H, respectively) of ‘Longshu 9’ from Quanzhou, Fujian, China. The total and differentially expressed miRNAs among samples were identified. Real-time PCR analysis of several miRNAs and viruses was performed to validate the quality of sequencing data. Target predication and functional enrichment for these miRNAs were analyzed. The association between miRNAs and virus infections would be discussed. [Result] After the alignment to the virus database of sweet potato, three samples (without 1H) were simultaneously infected with common sweet potato viruses, including
Sweet potato chlorotic stunt virus (SPCSV),
Sweet potato virus 2 (SPV2),
Sweet potato feathery mottle virus (SPFMV),
Sweet potato virus G (SPVG), and
Sweet potato virus C (SPVC), although they showed different pathological symptoms. In addition, uncommon viruses were identified in different samples. Using PCR analysis of SPFMV and SPVC viruses, the consistence with the sequencing data was validated. Using sequencing analysis, 679 known mi RNAs and 1 004 novel mi RNAs were found in these four samples. With comparative analysis, it was identified that 288 known mi RNAs and 433 novel miRNAs were differentially expressed among these four samples. These miRNAs showed different expression profiles among samples, such as the members of miR-156, miR-157, and miR-166 families. The qRT-PCR analysis showed these expression profiles of several miRNAs (including miR-156, novel-miR-40 and miR-319m) were in consistence with their profiles by sequencing. In comparison with that in virus-free seedling, the expression of three miRNAs (miR-160a, miR-2096 and miR-5387b) was differentially upregulated in these four sequencing samples. These results suggested that these miRNAs might be related to virus infections. Further target predication found that most of these miRNA targets were transcription factors, including the genes encoding ZFP, WD, Myb, and SPL domain-containing proteins. The enrichment analysis for those targets showed that they were associated with plant growth and development, morphogenesis, and stress resistance via regulating genes, signaling pathways, and antigen recognition. These represented the multipotent functions of these miRNAs’ targets. [Conclusion] Different sweet potato viruses induced differences in miRNA profiling, and these miRNAs were mainly associated with plant growth, resistance and plant defense.
