Scientia Agricultura Sinica

Plant Type Characteristics and Evolution of Main Economic Characters in Early Maturing Upland Cotton Cultivar Replacement in Xinjiang

CHEN MinZhi,YANG YanLong,WANG YuXuan,TIAN JingShan,XU ShouZhen,LIU NingNing,DANG Ke,ZHANG WangFeng

Scientia Agricultura Sinica. 2019, 52(19): 3279-3290. doi:10.3864/j.issn.0578-1752.2019.19.001

Abstract ( 520 )

HTML ( 79 )

PDF (2773KB) ( 384 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 This paper analyzed the evolution trend of plant type characteristics and main economic traits in the process of improving the yield of early-maturing upland cotton (Gossypium hirsutum L.) in Xinjiang, combined with the demand for the characteristics of cultivars in the development of machine-harvested cotton, and explained the changes of suitable machine-harvesting characteristics in cultivar replacement. It provides a theoretical basis for the breeding and cultivation management of new cotton varieties in Xinjiang. 【Method】 Large-scale main cultivars (Xinluzao 1, Xinluzao 7, Xinluzao 13, and Xinluzao 45) were used as experimental materials under mulched drip irrigation condition. A total of eleven plant type characters and the evolution of major economic traits were analyzed, including the eleven plant type characters of the length of the first fruit node, inter-node length of fruit branch, ratio of fruit node/fruit branch, plant height, node of first fruit branch, height of first fruit branch, the angle between fruit branch and main stem, the number of fruit branches, the number of vegetative branches, width of the fourth leaf from the top, and stem diameter. 【Result】 With the cotton cultivar replacing, the length of the first fruit node, inter-node length of fruit branch, and the ratio of fruit node/fruit branch increased gradually. The plant type changed from compact to loose. Plant height, node of first fruit branch, and height of first fruit branch increased gradually. The angle between fruit branch and main stem of upper-canopy was gradually reduced, and the fruit branch was lifted, which has high plant-type characteristics. According to the requirements of cotton machine harvesting characteristics. It shows that 2010s cultivars had plant type characters with high yield. The length of the first fruit node and the angle between fruit branch and main stem of 2010s cultivars was more in line with the requirements of machine-harvested cotton. There was no significant differences in number of fruit branches, number of vegetative branches, width of the fourth leaf from the top, and stem diameter among cultivars of different ages. The lint yield, total boll number, and lint percentage increased gradually with the cotton cultivar replacing. The lint yield of the 1980s, 1990s, 2000s, and 2010s was 23%-53%, 16%-20%, 13%-14%, and -2%-6% higher than the yield of regional experiment year. The modern high-yield cultivation techniques under mulched drip irrigation plays an important role on yield improvement. However, the harvest index of 2000s and 2010s cultivars were significantly lower than the 1990s cultivars. Compared with the 1980s and 1990s cultivars, the upper boll period of the 2010s cultivars was reduced 4-5 days, the boll opening were relatively concentrate, sensitive to defoliant. There was no significant difference in boll opening rate, and they were greater than 95%. But the growth period was longer. Compared with the growth period of the trial cultivars, the 1980s and 1990s cultivars were advanced by 3-7 days, and the 2000s and 2010s cultivars were advanced by 0-3 days. This may be related to the application of the technique of precocious cultivation under mulched drip irrigation. The fiber length, fiber strength, elongation, and fiber spinning consistency index of 2000s and 2010s cultivars improved obviously. But the Micronaire was relatively large. The improvement of fiber strength was at the expense of fiber fineness, and the fiber quality coordination was not good. 【Conclusion】 During the process of increasing yield of cotton cultivar replacement, economic characteristics of cotton improved, but the increasing yield of plant type changed from compact to loose, with long growth period, low harvest index, and large Micronaire. With the application of the machine-harvesting mode, the breeding and selection of cultivars with excellent fiber quality and suitable machine-harvesting are the key to ensuring the steady development of the cotton industry Xinjiang.

Comprehensive Assessment on Cold Tolerance of the Strong Winter Brassica napus L. Cultivated in Northern China

PU YuanYuan,ZHAO YuHong,WU JunYan,LIU LiJun,BAI Jing,MA Li,NIU ZaoXia,JIN JiaoJiao,FANG Yan,LI XueCai,SUN WanCang

Scientia Agricultura Sinica. 2019, 52(19): 3291-3308. doi:10.3864/j.issn.0578-1752.2019.19.002

Abstract ( 415 )

HTML ( 17 )

PDF (6346KB) ( 279 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 In this study, the cold tolerance of twelve strong winter Brassica napus, which planted in northern China, were compared. The degree of cold tolerance was clearly classified by three identification methods. It provides a scientific and reliable identification method and varieties (lines) with strong cold tolerance, for improvement of Brassica napus in northern China. 【Method】 Twelve strong winter Brassica napus varieties (lines) were used as the materials. In order to compare and analyze the difference of cold tolerance among these materials, we observed the morphology of seedlings before overwintering, recorded statistical overwintering rate and calculated the lethal temperature (LT₅₀), meanwhile, measured physiological indexes, and analyzed the relationship among cold tolerance, vernalization rate and the differences in growth stages after sowing in early spring. Then, we used LT₅₀, subordinate function and comparison of vernalization differences, respectively, to clarify the cold tolerance classification of twelve Brassica napus. 【Result】 The overwintering survival rate of materials in Tianshui area (34°60′N, altitude 1 084-1 650 m) was 92.1%-97.8%. However, the overwintering survival rate decreased rapidly after moving to Lanzhou (36°73′N, altitude 1 517 m) and Shangchuan (36°03′N, altitude 2 150 m), the overwintering survival rate was 0-14.4%, (plastic film mulch) and 36.0%-78.6% (plastic film mulch) respectively. The strong winter Brassica napus lines ‘16TS 309-4, 16TS 306-3, 16TS 309-10, 15NS 45-4, 2016 8(G) and 2016TSG (10)’ which were new bred by Gansu Agricultural University could survive over winter, with the average overwintering survival rate of 10.2%-14.4%. Before overwintering, the seedlings of these new materials tended to prostrate growth, the colors of heart leaves and young stems were yellow-green or purple, the color of leaves was dark green, the accumulation of underground dry matter was greater than aboveground dry matter, and the root shoot ratio increased which was between 0.23 to 0.95, with a significant difference (P＜0.05). Under cold stress, leaves kept relatively high enzyme activity of super oxide dismutase (SOD), peroxidase (POD) and catalase (CAT), moreover, the high content of soluble protein (SP), soluble sugar (SS) and free proline (Pro) was detected, and LT₅₀ was relatively lower (range from -13.4℃ to -5.7℃). In the field experiment, twelve winter rapeseeds were sowed in early spring, the results have shown that the vernalization rate was between 4.05% and 87.65%, and ‘2016TS (G) 10’ was the lowest one. However, ‘2016TS (G) 10’ not only has the lowest vernalization rate (4.05%), but also the average plant height (10.77 cm), the average blot height of plants in the not budding stage (10.50 cm) and the average blot height of plants in budding stage (17.10 cm) were all the lowest one. Correlation analysis showed that the vernalization rate was significantly positively correlated with the average plant (bolt) height, the proportion of mature plants and LT₅₀, with R ²of 0.90-0.96, and significantly negatively correlated with overwintering survival rate, LT₅₀, comprehensive evaluation value (D), CAT, POD and SP, with R ² of -0.96--0.63.【Conclusion】 In northern China, sowing winter rapeseeds in the early spring, according to the difference of vernalization rate, growth stage and average plant (blot) high, the cold tolerance of winter rapeseeds were evaluated. The seven new lines of Brassica napus bred by Gansu Agricultural University showed strong cold tolerance, could over winter in the area of 36°03′N, altitude 2 150 m, and the cold tolerance was significantly strong than Tianyou 14, Tianyou 2288 (bred by Tianshui Agricultural Science Research Institute) and Xinyou 23 (bred by Xinjiang Academy of Agricultural Sciences), that is an essential germplasm resource with strong cold tolerance for Brassica napus breeding in northern China.

Effects of Phytase Q9 on Yield Formation of Summer Maize Shading in the Field

HUANG XinHui,GAO Jia,REN BaiZhao,ZHAO Bin,LIU Peng,ZHANG JiWang

Scientia Agricultura Sinica. 2019, 52(19): 3309-3322. doi:10.3864/j.issn.0578-1752.2019.19.003

Abstract ( 388 )

HTML ( 26 )

PDF (532KB) ( 304 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Summer maize in Huang-Huai-Hai region has frequent rainy season and few sunshine. The increase of planting density affects the population light. It is important to study the regulation of phytase Q9 on the growth and yield of summer maize under shade in the field.【Method】 From 2013 to 2018, a maize variety of Denghai 605 was selected as the experimental material under field conditions, with a planting density of 67 500 plants/hm ². Three shading treatments were set, including shading from tassel stage to maturity stage (S1), shading from six-leaf stage to tassel stage (S2), and shading from emergence stage to maturity stage (S3), with natural lighting in the field as control (CK). The field shading rate was 60%. In addition, chemical control reagent phytase Q9 was selected to regulate the shading treatment and the CK exogenously, namely shading from tassel stage to maturity stage-phytase Q9 (Z-S1), shading from six-leaf stage to tassel stage-phytase Q9 (Z-S2), shading from emergence stage to maturity stage-phytase Q9 (Z-S3), and natural lighting-phytase Q9 (Z-CK). Spraying clear water at the same time was the control. The effect of phytase Q9 on yield formation of summer maize under field shade was studied.【Result】 Compared with the control, shading treatment delayed the growth and development of summer maize, prolonged the interval between males and females, and delayed the period of male drawing and silking for about 6 days. Under shading treatment, leaf area index, SPAD value of functional leaves, and dry matter accumulation decreased significantly, ear length and ear diameter decreased, bald top lengthened, plant height and ear height decreased, lodging rate and empty stem rate increased, and then yield decreased significantly. After spraying plant enzyme Q9, the whole growth period of shading and earing period of shading were 1-2 days earlier than that of the control; The interval between male and female was shortened by 1 day; The leaf area index, SPAD value, ear height and plant height increased significantly; Dry matter accumulation and its distribution to grains increased, while lodging rate and empty stem rate decreased under different shading treatments; The traits of shaded panicle were improved during the whole growth period. The positive regulation of phytase Q9 on these indexes indirectly increased 1000-grain weight, grain number per ear and ear number per hectare of summer maize, and the yield increased significantly. Compared with the control, shading at full growth stage, ear stage and flower and grain stage increased yield by 21%, 9% and 14%, respectively. 【Conclusion】 Spraying phytase Q9 could effectively alleviate the damage caused by low light stress in summer maize.

Effects of Different Colored Plastic Film Mulching and Planting Density on Soil Temperature, Evapotranspiration and Yield of Spring Maize

SUN ShiJun,ZHU ZhenChuang,CHEN ZhiJun,YANG Dan,ZHANG XuDong

Scientia Agricultura Sinica. 2019, 52(19): 3323-3336. doi:10.3864/j.issn.0578-1752.2019.19.004

Abstract ( 483 )

HTML ( 33 )

PDF (667KB) ( 319 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Field experiments were conducted to explore the effects of different colored plastic film mulching and planting density on the topsoil temperature, evapotranspiration, grain yield of spring maize and precipitation utilization efficiency in the rain-fed area of Northeast China, in order to further tap the water production potential of dryland and rain-fed maize. 【Method】 Complete combination field, including three types of mulching ( non-mulching, transparent plastic film mulching and black plastic film mulching ) and three planting densities ( 60 000, 75 000 and 90 000 plants/hm ²) , were conducted to monitor the topsoil temperature dynamics in 0-25 cm depths and the soil moisture dynamics in 0-120 cm depths, and to analyze the water use efficiency combined with grain yield of maize in 2016-2018.【Result】 The results showed that the accumulated temperature of the plough layer in the transparent mulching film treatment was significantly higher than that in the black mulching film, and the accumulated temperature of the plough layer in the black mulching film treatment was significantly higher than that in the non-mulching treatment in the early growth stages of maize. The increase of planting density reduced the accumulated temperature of the plough layer after jointing stage of maize. For the evapotranspiration of the growing season, there was no significant difference between the black plastic film mulching treatment and the transparent plastic film mulching treatment, but they were significantly lower than the non-mulching treatment. The evapotranspiration increased with the increasing of the planting density whether in the normal precipitation year or the dry year. Maize grain yields and water use efficiency were significantly improved in the black plastic film mulching treatment, with an average of 4.3% and 4.6% higher than that of the transparent plastic film mulching treatment, respectively, and 9.2% and 13.3% higher than that of the non-mulching treatment, respectively. Yield and water use efficiency increased in tandem with planting density under the same mulching treatment. The plastic film mulching significantly improved the economic benefits under high-density treatment, and the profit of the black plastic film mulching was 807.82 yuan/hm ² more than that of the transparent plastic film mulching.【Conclusion】 The cultivation mode of black plastic film mulching and high density (90 000 plants/hm ²) combined treatment could improve the utilization rate of natural precipitation and achieve the highest water use efficiency on the basis of ensuring high grain yields. This paper provided a scientific and effective way to further tap the water and crop production potential in the dryland and rain-fed regions of China

Effect of Midgut Specific Binding Protein ABCC1 on Cry1Ac Toxicity Against Helicoverpa armigera

CHEN Lin,WEI JiZhen,LIU Chen,NIU LinLin,ZHANG CaiHong,LIANG GeMei

Scientia Agricultura Sinica. 2019, 52(19): 3337-3345. doi:10.3864/j.issn.0578-1752.2019.19.005

Abstract ( 252 )

HTML ( 17 )

PDF (857KB) ( 212 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The objective of this study is to research the binding characteristics of midgut protein ABCC1 from Helicoverpa armigera (HaABCC1) to Cry1Ac and the effect of ABCC1 on toxicity of Cry1Ac, and to clarify the role of HaABCC1 in the insecticidal mechanism of Cry1Ac. 【Method】 To verify the binding ability of HaABCC1 with Cry1Ac in vitro, the sequence of HaABCC1 was analyzed and the primers were designed, two heterologously transmembrane protein fragments of HaABCC1 were expressed, and then Ligand blot experiment was conducted. The changes of expression level of HaABCC1 and mortality of larvae exposed to Cry1Ac were tested after silenced HaABCC1 by microinjected siRNA into the abdomen of 3rd instar larvae. The cell mortality changes of Sf9 insect cell line treated by Cry1Ac were compared using cell bioassay method, after transfected HaABCC1 into Sf9 and confirmed the pAc-ABCC1 recombinant plasmid was successfully transferred into Sf9. The difference of full-length HaABCC1 between Cry1Ac-resistant strain (BtR) and susceptible strain (96S) was compared, the expression of HaABCC1 in BtR and 96S was detected using qRT-PCR. 【Result】 The two HaABCC1 transmembrane fragments, TMD1 and TMD2, were successfully expressed in Escherichia coli BL21 (DE3) cells, these two heterologously expressed HaABCC1 fragments could bind to actived-Cry1Ac in vitro. The expression level of HaABCC1 significantly reduced after injection of siABCC1 into abdomen of the H. armigera larvae. Compared with non-treated, DEPC water- and siEGFP-injected larvae, the mortality of H. armigera larvae which were knocked down HaABCC1 significantly decreased after treated with actived-Cry1Ac. It was showed the toxicity of Cry1Ac against H. armigera larvae significantly reduced after the HaABCC1 silence. Compared with Sf9 control, the mortality of cell line which HaABCC1 expressed in Sf9 obviously increased after treated by actived-Cry1Ac. The result indicated that transfection HaABCC1 into Sf9 could significantly increase the cell mortality after Cry1Ac treatment. There was no difference in the cDNA sequence and amino acid sequence of HaABCC1 between susceptible strain (96S) and Cry1Ac-resistant strain (BtR), but the expression level of HaABCC1 significantly reduced in BtR resistant strain compared with 96S susceptible strain. 【Conclusion】 HaABCC1 of H. armigera is a specific binding protein and may be a functional receptor protein of Cry1Ac, it may involve in the resistance of H. armigera to Cry1Ac.

Selection of Stable Internal Reference Genes for Transcript Expression Analyses in Laodelphax striatellus Under Near-Zero Magnetic Field

LIU FanQi,WAN GuiJun,ZENG LuYing,LI ChunXu,PAN WeiDong,CHEN FaJun

Scientia Agricultura Sinica. 2019, 52(19): 3346-3356. doi:10.3864/j.issn.0578-1752.2019.19.006

Abstract ( 306 )

HTML ( 20 )

PDF (486KB) ( 176 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】 The geomagnetic field (GMF) is not constant, it can change with time and space. At present, with the development of research on animal magnetic biology, the study on transcriptional profiling of magnetic response genes with quantitative real-time PCR (qRT-PCR) has greatly promoted the identification of magnetic response pathway and the uncovering of magnetoreception mechanism.【Objective】 The objective of this study is to screen the internal reference genes of the brachypterous small brown planthopper (Laodelphax striatellus) under near-zero magnetic field (NZMF), and to make the quantification of target genes more accurate.【Method】 The population of L. striatellus, a migratory insect, was collected from the experimental fields of Jiangsu Academy of Agricultural Sciences and expanded indoors using TN1 three-leaf rice seedlings (temperature: (25.0±1.0)℃, relative humidity: 70%-90%, photoperiod: 14L﹕10D). Helmholtz coils system was used to simulate the near-zero magnetic field (NZMF; ＜500 nT) vs. geomagnetic field (GMF; ~ 50 000 nT), the artificial simulated magnetic field intensity was homogeneous within a spherical space with a diameter of 30 cm. During the experiment, environmental factors other than the magnetic field intensity were strictly controlled (temperature: (25.0±1.0)℃, relative humidity: 75%, photoperiod: 14L﹕10D) and the artificial simulated magnetic field was calibrated and monitored daily using a fluxgate magnetometer. The L. striatellus and TN1 three-leaf rice seedlings were placed in a test tube for exposure treatment. Every two days, the rice seedlings in control and treatment magnetic fields were swapped to avoid the influence triggered by the potential magnetic response of rice seedlings on L. striatellus. Trizol method was used to extract the total RNA of the female and male adults of L. striatellus, respectively. The quality of total RNA was inspected and adjusted to the same mass, and cDNA was then made by reverse transcription. Using qRT-PCR technique and combined with the common internal reference selection software including geNorm, NormFinder, BestKeeper, and the online integrated analysis system RefFinder, the stability of internal reference genes in L. striatellus under NZMF and GMF was evaluated and screened. Among them, 11 common candidate internal reference genes to be evaluated included Actin1, Tubulin (α1TUB and α2TUB), Elongation factor 1 alpha (EF-1α), Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Ubiquitin (UBI), Ribosomal protein S11 (RPS11), Ribosomal protein S15e (RPS15), Ribosomal protein L8 (RPL8), Ribosomal protein L9 (RPL9), and ADP ribosylation factor2 (ARF2). 【Result】 For brachypterous female adults under different magnetic field environments (NZMF vs. GMF), the expression stability of EF-1α and RPL9 ranked as the top two in the two assessment software of geNorm and NormFinder, which was slightly different from the results of BestKeeper software. Furthermore, the stability of the above three methods was sorted by online tool RefFinder. The results showed that the stability of EF-1α was the best, followed by RPL9. For brachypterous male adults under different magnetic field environments (NZMF vs. GMF), based on the three evaluation methods of geNorm, NormFinder, and BestKeeper, the expression stability of α2TUB and RPL9 ranked as the top two. Although the expression stability of Actin1 was in the top two in NormFinder and BestKeeper, its stability was low in geNorm. Finally, through the online tool RefFinder synthesis analysis, it was shown that the stability of α2TUB was the best, followed by RPL9. 【Conclusion】 Stably expressed reference genes in the brachypterous male and female adults of L. striatellus were clarified under different magnetic field intensities (NZMF vs. GMF). For a double reference gene system, the combination of EF-1α and RPL9, and the combination of α2TUB and RPL9 can be used in the brachypterous female and male adults, respectively, which is a stable reference gene system. Also, RPL9 can be used alone as a stable reference gene in both male and female brachypterous adults of L. striatellus. The results of this study ensure the accurate quantification of transcription expression of key target genes in response to changes in magnetic field intensity, and provide a strong guarantee for the future analysis of transcription expression profile under changes in magnetic field intensity.

Regulation Function of Trehalose-6-phosphate Synthase Genes on Chitin Synthesis in Sogatella furcifera

ZHANG DaoWei,YU YaYa,PAN BiYing,KANG Kui,ZENG BoPing,CHEN Jing,TANG Bin

Scientia Agricultura Sinica. 2019, 52(19): 3357-3366. doi:10.3864/j.issn.0578-1752.2019.19.007

Abstract ( 327 )

HTML ( 16 )

PDF (1147KB) ( 209 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】 It is well known that trehalose-6-phosphate synthase (TPS) plays an important role in trehalose synthesis, which can mediate trehalose metabolism to regulate chitin synthesis and insect development. 【Objective】 In this study, the effect of silencing SfTPS was detected, the molting status of Sogatella furcifera was observed and the content of chitin and the quantitative expression of chitin synthase (CHS) gene were determined through inhibiting the expression of TPS by RNAi in S. furcifera. The purpose is to explore the potential regulatory effects of SfTPS on the chitin synthesis in S. furcifera.【Method】 The S. furcifera population, which has been fed in laboratory for many years, was used as experimental material. The double-stranded RNA (dsRNA) of SfTPS and GFP were synthesized in vitro in order to study the potential function of TPSs, the RNA of two dsSfTPSs (dsSfTPS1 and dsSfTPS2) was injected into S. furcifera, respectively. Firstly, after dsRNA injection, the total RNA of S. furcifera was extracted by Trizol method at 48 h, and the first strand DNA was synthesized as the template of quantitative real-time PCR (qRT-PCR). As well as qRT-PCR was used to detect the silencing of SfTPS expression for the effect of RNAi. Secondly, the whole chitin of S. furcifera was detected at 48 and 72 h after dsRNA injection, and photographs were taken of the winged developmental malformations. Finally, the relative expression level of SfCHS in S. furcifera was detected by qRT-PCR, and the roles of SfTPS1 and SfTPS2 in the regulation of chitin synthesis were analyzed.【Result】 Compared with dsGFP injection, the expression of SfCHS increased after dsSfTPS1 and dsSfTPS2 injection, as well as the chitin content increased, which lead to the wing deformity of S. furcifera. The qRT-PCR results showed that the expression of SfTPS was significantly inhibited after dsRNA injection of a single SfTPS, which was less than 30% of that in the control group injected with dsGFP. In addition, the expression of another SfTPS also decreased significantly after a single SfTPS dsRNA injection. The adult wings of S. furcifera were all long wings after dsSfTPS1 and dsSfTPS2 injection. Some deformities such as wing curl in a certain ratio had been found in these long wings, and a certain ratio of mortality was found at 48 and 72 h. The chitin content increased significantly at 72 h after these two dsSfTPSs RNA injection. Compared with the control group, the expression of SfCHS1 and SfCHS1a increased significantly at 72 h after dsSfTPS1 injection, followed it increased significantly at 48 and 72 h after dsSfTPS2 injection. In the same time, the expression of SfCHS1b increased significantly after dsSfTPS1 and dsSfTPS2 injection.【Conclusion】 The SfTPS can control the synthesis of chitin through the regulation of chitin synthase gene in S. furcifera. The results are helpful to evaluate the regulatory role of SfTPS in S. furcifera and other insects and as the potential pest control target. It provides a theoretical basis for further development and screening of effective trehalose-6-phosphate synthase inhibitors to control S. furcifera pests and so on.

Heavy Metal Accumulation in Irrigated Desert Soils and Their Crop Effect After Applying Different Organic Materials

SONG ZiRong,E ShengZhe,YUAN JinHua,JIA WuXia,ZENG XiBai,SU ShiMing,BAI LingYu

Scientia Agricultura Sinica. 2019, 52(19): 3367-3379. doi:10.3864/j.issn.0578-1752.2019.19.008

Abstract ( 299 )

HTML ( 22 )

PDF (531KB) ( 256 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 This study aimed to explore the long-term effects of organic materials application on heavy metal content, fractionation, crop uptake in irrigated desert soil, and in further to provide a theoretical basis and technical support to control soil heavy metals accumulation during fertilization with organic materials. 【Method】 A long-term (7 years) positioning experiment was conducted by applied with 6 types of organic materials, including chicken manure, cattle manure, pig manure, sludge, biogas residue and mushroom residue, in irrigated desert soil. Subsequently, soil heavy metal content, fractionation and crop uptake were analyzed. 【Result】 Application with chicken manure, pig manure or sludge significantly increased the soil Cu and Zn content, which was in the order of pig manure treatment＞chicken manure treatment＞sludge treatment. No significant effect on soil heavy metals was observed for the other organic materials. After application with pig manure, chicken manure and sludge, soil Cu content increased by 62.20%, 20.10% and 10.26%, respectively, while soil Zn increased by 79.98%, 39.24% and 18.31%, respectively, showing an increasing trend with application year; the average annual cumulative rates of Cu were 4.16, 1.25 and 0.97 mg·kg ^-1·a ^-1, while which for Zn were 11.04, 4.86 and 2.59 mg·kg ^-1·a ^-1, respectively; No significant effect on soil Cd, Cr, Pb and Ni was observed. The application of cattle manure, mushroom residue and biogas residue had no significant effect on the total content of Cu and Zn in soil. Application with Pig manure, chicken manure, cow manure and sludge significantly affected the forms of Cu and Zn in soil, and significantly increased the proportion of the effective forms and total content of Cu and Zn in soil. 【Conclusion】 Long-term application of pig manure, chicken manure and sludge could lead to the rapid accumulation of Cu and Zn and the increase in Cu and Zn bioavailability in irrigated desert soil, especially for pig manure. In the future, more concern is needed for the heavy metals in organic fertilizers during soil fertility improvement, so as to reduce heavy metal accumulation in soil and sustaining the soil healthy and agricultural use.

Effects of the Different Autumn Irrigation Years on Soil Bacterial Community in Hetao Irrigation District

ZHANG XiaoLi,ZHANG HongYuan,LU Chuang,PANG HuanCheng,JIN CunWang,GAO Xi,CHENG AiPing,LI YuYi

Scientia Agricultura Sinica. 2019, 52(19): 3380-3392. doi:10.3864/j.issn.0578-1752.2019.19.009

Abstract ( 295 )

HTML ( 25 )

PDF (846KB) ( 309 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Considering the phenomenon that farmers voluntarily gave up the water irrigation in autumn, We investigated the effects of different autumn irrigation years on soil bacterial community composition in Inner Mongolia Hetao Irrigation District, so as to provide corresponding scientific support for the improvement of saline-alkali land and reformation of autumn irrigation system.【Method】 By selecting five types of typical plots, including wasteland (CK), always irrigation in autumn (AUI1), 2-3 years with autumn irrigation (AUI2), 3-4 years without autumn irrigation (AUI3) and 6-7 years without autumn irrigation (AUI4), the characteristics of soil bacteria in different autumn irrigation years were analyzed by high-throughput sequencing (Illumina HiSeq), and redundantly and correlation analysis of the soil chemical properties with bacterial communities and with community composition were followed.【Result】 The results showed that the salt content of AUI1 and AUI2 treatments were significantly reduced in 0-30 cm soil layer, compared with CK, AUI3 and AUI4, which were reduced by 128.82% and 29.04%, 108.76% and 17.72%, 108.44% and 17.55%, respectively. The salt content of AUI1 treatment was significantly reduced than that of other treatments in 30-40cm soil layer; the pH of AUI2 treatment was the lowest in each soil layer, and compared with CK, AUI1, AUI3 and AUI4 treatments, which reduced by 0.28, 0.32, 0.16 and 0.88 units, respectively (P＜0.05). Compared with CK, AUI1, AUI3 and AUI4 treatments, the soil microbial biomass carbon content of AUI2 treatment were increased by 252.89%, 148.59%, 58.10% and 60.10%, respectively, and the soluble organic carbon content increased by 48.41%, 29.42%, 6.01% and 4.27%, respectively (P＜0.05). The abundance index (ACE and Chao1) of AUI1 and AUI2 treatments were significantly higher than CK, AUI3 and AUI4 treatments (P＜0.05). Proteobacteria, Acidobacteria and Bacteroidetes were the three dominant bacteria that were treated in different autumn years, accounting for 53.93% of all bacteria, while AUI2 and AUI3 treatment are beneficial to increase the Bacteroidetes and Acidobacteria relative abundance (P＜0.05). Correlation analysis showed that Proteobacteria and Chloroflexi were significantly negatively correlated with soil microbial biomass carbon and soluble organic carbon, and the correlation coefficient with microbial biomass carbon were (r =-0.559** and -0.522*), the correlation coefficients with soluble organic carbon were (r =-0.795** and -0.820**), respectively; Actinobacteria, Thaumarchaeota, Firmicutes and Verrucomicrobia were significantly negatively correlated with soil salinity and significantly positively correlated with soil microbial biomass carbon and dissolved organic carbon. Factor analysis showed that soil salinity, pH, microbial biomass and soluble organic carbon were main environmental factors on the soil bacterial community structure, total explaining 97% of the community changes. The order of contribution rate was soil SC＞pH＞MBC＞SOC.【Conclusion】 Comprehensive consideration, the 2-3 years with autumn irrigation (AUI2) treatment could not only effectively reduce the soil salinity and significantly increase the microbial biomass carbon and soluble organic carbon content in 0-40cm soil layer, but also improve the relative abundance of the dominant bacteria. In summary, the autumn irrigation (AUI2) was an optimization measure for the improvement of saline soil and water conservation in Hetao area.

Isolation and Application of Effective Rhizobium Strains in Peanut on Acidic Soils

LIU Peng,TIAN YingZhe,ZHONG YongJia,LIAO Hong

Scientia Agricultura Sinica. 2019, 52(19): 3393-3403. doi:10.3864/j.issn.0578-1752.2019.19.010

Abstract ( 615 )

HTML ( 23 )

PDF (1501KB) ( 295 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】 Peanut (Arachis hypogaea L.) is an important oil and economic crop in the world. Most of the peanut cultivation soils in South China are acidic. Since low pH value, nutrition deficiencies and aluminium (Al) toxicity on acidic soils severely limit yield and biological nitrogen fixation (BNF) capacity in peanut. 【Objective】 The purpose of this paper is to isolate acidic soil adaptive rhizobium stains to improve BNF and yield of peanut, as well as to remediate acidic soils.【Method】 Firstly, strains were isolated and purified from fresh peanut nodules by collecting from the field by streak plate method combined with microscope observation, the nodulation gene nodA and nitrogen fixing gene nifH were detected by PCR to preliminary identification of potential Rhizobia strains, and then 16S rRNA sequencing was used for further taxonomy identification of the isolate strains. The symbiotic nodulation and nitrogen fixation ability of potential Rhizobium strains were validated by inoculation to the peanut under hydroponics conditions. Further, the candidate rhizobium strains in the field trial on acidic soils were evaluated. 【Result】 A total of 256 microbe strains were isolated and purified from nodules of peanuts grown in different sites on acidic soils. Based on the results of 16S rRNA sequencing analysis, ten of them contained nodA and nifH, and were initially identified as potential rhizobium. Of which, 8 strains belonged to Bradyrhizobium sp. and 2 belonged to Rhizobium sp. Hydroponic experiments further confirmed that the 10 strains could form functional nodules with peanuts. Subsequently, 4 strains with higher BNF capacity were selected for field evaluation on acidic soils. The results showed that all the 4 strains successfully formed functional nodules with peanuts in the field. On contrary, none of nodules could be formed in peanuts without rhizobium inoculation. Besides, Rhizobia inoculation significantly improved N nutrition, and increased biomass and yield of peanut. By comparison with CK plants, biomass, yield and N content of peanuts inoculated with rhizobium strains were increased by 27.1%-38.0%, 24.7%-104.2% and 73.9%-151.3%, respectively. 【Conclusion】 Taken together, the peanut Rhizobia isolated and identified in this study could fix N₂ effectively and adapted well to acidic soils, and therefore which had great application potentials.

Cloning, Subcellular Localization and Expression Analysis of CitPG34 in Citrus

GE Ting,HUANG Xue,XIE RangJin

Scientia Agricultura Sinica. 2019, 52(19): 3404-3416. doi:10.3864/j.issn.0578-1752.2019.19.011

Abstract ( 393 )

HTML ( 18 )

PDF (4331KB) ( 256 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Polygalacturonases (PGs) play important roles in plant growth and development as well as organ abscission by degrading pectin in cell wall. In this study, a citrus PG gene (i.e., CitPG34) and its promoter (CitPG34-P) were cloned and expression analyzed based on our previous data, which would provide a basis for further elucidating the function of CitPG34 in citrus fruitlet abscission.【Method】 The full length of CitPG34 gene and its promoter was cloned from ‘Tarcocco’ blood orange (Citrus sinensis L. Osbeck). The protein characteristics and cis-acting elements on promoter were analyzed by ProtParam, Cello, CLUSTALX, MEGA5.2, and PlantCARE, etc. The gene expression level was detected by real-time Quantitative PCR (qRT-PCR). The PCAMBIA1302-CitPG34-GFP fusion protein expression vector for subcellular localization and CitPG34-P expression vector (CitPG34-P::gus) for promoter activity analysis were constructed by homologous recombination, respectively.【Result】 The ORF of CitPG34 was 1 194 bp in length, encoding 397 amino acids. The predicted molecular weight of CitPG34 was 41.47 kD, the theoretical pI was 5.19, and the instability coefficient was 30.23, indicating that CitPG34 belonged to stable protein. TMHMM analysis showed that CitPG34 was a transmembrane protein, the transmembrane domain locating between the amino acid residue 7 and 29. In the secondary structure of CitPG34, the alpha-helix structure, extended chain and random coil account for 15.37%, 29.72% and 54.91%, respectively, which were nearly consistent with its tertiary structure. NJ tree analysis showed that CitPG34 was close to PcPG3 (BAF42034), a pear PG, indicating that it might be related to fruit abscission and softening. qPCR analysis showed that CitPG34 dominantly expressed in flowers, followed by roots, leaves, abscission zone A (AZ A) and C (AZ C), and almost undetected in fruits. In AZ A, the expression level of CitPG34 was significantly up-regulated by ACC, whereas inhibited by IAA, showing the role in citrus fruitlet abscission. Subcellular localization revealed that CitPG34 was mainly located in cell wall. A 2 075 bp promoter sequence of CitPG34 was cloned, which contained several cis-regulatory elements, including TATA-box, enhancer CAAT-box and ABRE, etc. GUS histochemical staining revealed that the GUS activity in vein and trichomes was remarkably up-regulated by ethylene. 【Conclusion】 The ORF length of CitPG34 gene was 1 194 bp, encoding 397 amino acids. CitPG34 was mainly located in cell wall. qPCR analysis showed that CitPG34 dominantly expressed in flowers and was significantly associated with citrus fruitlet abscission. Taken together, these results indicated that CitPG34 played important roles in citrus fruitlet abscission and flower development.

Cloning and Function Analysis of Gibberellin Insensitive DkGAI2 Gene in Nantongxiaofangshi (Diospyros kaki Linn. cv. nantongxiaofangshi)

JIANG MengTing,ZHU Ning,GONG HongYong,HOU YingJun,YU XinYi,QU ShenChun

Scientia Agricultura Sinica. 2019, 52(19): 3417-3429. doi:10.3864/j.issn.0578-1752.2019.19.012

Abstract ( 324 )

HTML ( 26 )

PDF (6236KB) ( 273 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 In this study, the full-length sequence of gibberellin insensitive gene (GAI2) was obtained from the leaf of Nantongxiaofangshi (Diospyros kaki Linn. cv. nantongxiaofangshi), named as DkGAI2. The subcellular localization and expression characteristics of DkGAI2 gene were analyzed. Then DkGAI2 gene was transformed into plant tobacco, and the morphological and physiological indicators of the transgenic tobacco plants were determined. Our study would provide a theoretical basis for the future research of GAI gene.【Method】 The full-length sequence of DkGAI2 gene was cloned from Nantongxiaofangshi by RT-PCR, 3’ RACE and 5’ RACE using the labeled GAI2 gene as the original sequence of high-throughput transcriptome sequencing of Nantongxiaofangshi (Unpublished). Sequence characteristics were analyzed by bioinformatics. The expression characteristics of DkGAI2 gene in five different phenological stages of Dafangshi and Nantongxiaofangshi, and the expression level of DkGAI2 gene in different tissues of Nantongxiaofangshi was detected by real-time quantitative PCR (qRT-PCR). The transient expression vector pCAMBIA-GFP-1302-DkGAI2 was constructed and was transiently infected with tobacco to analyze the subcellular localization of DkGAI2 gene. DkGAI2 gene driven by the 35S promoter was constructed and delivered into plant tobacco by Agrobacterium-mediated transformation approach. Transgenic plants were identified by using GUS staining and RT-PCR. After transplanting, the plant height, internode length, leaf aspect ratio and the content of GA₁and GA₄ in transgenic tobacco plants were measured at the first flowering stage.【Result】 1 827 bp of DkGAI2 was cloned from Nantongxiaofangshi, the nucleotide sequence of DkGAI2 gene shared 72%-80% in homology compared with kiwifruit (KF588651.1), light skin (MF149049.1), pear (KX078214.1), apple (FJ535245.1) and grape (MG738718.1). DkGAI2 gene containing DELLA and GRAS conserved special domain, belonging to DELLA protein gene family. DkGAI2 gene encoding a putative protein about 608 amino acids, the relative molecular mass of DkGAI2 gene was 66.5 KD, the theoretical isoelectric point was 5.54, and the instability coefficient iwas 50.41, without obvious hydrophobic region, without transmembrane domain and signal peptide. Phylogenetic analysis showed that the DkGAI2 gene had close relationship with grape. qRT-PCR result showed that the expression level of DkGAI2 gene in five different phenological stages of Nantongxiaofangshi was higher than that of Dafangshi. DkGAI2 gene showed tissue expression specificity in different tissues of Nantongxiaofangshi, which had the highest expression in old leaves, followed by young leaves and shoot tips, while it had the lowest expression in fruitlet. The green fluorescent signal of the pCAMBIA-GFP- 1302-DkGAI2 fusion protein was located in the nucleus, indicating that DkGAI2 gene localized in the nucleus. After GUS staining and RT-PCR detection, 5 transgenic tobacco lines of DkGAI2 gene were obtained. The GA₁ content of transgenic tobacco leaves were increased, the GA₄ content were decreased, the total content of GA₁ and GA₄were decreased, and the transgenic tobacco plants showed plant dwarfing phenotypes with shortened internodes, reduced leaf aspect ratio, and delayed flowering.【Conclusion】 DkGAI2 gene had tissue expression specificity; DkGAI2 gene localized in the nucleus, the expression level of DkGAI2 gene in Nantongxiaofangshi was higher than that of Dafangshi at the five different phenological periods. It was speculated that DkGAI2 may cause plant dwarfing by reducing GA₄content.

State-of-the-Art on the Processing and Comprehensive Utilization of the Apricot Kernels

ZHANG QingAn,YAO JianLi

Scientia Agricultura Sinica. 2019, 52(19): 3430-3447. doi:10.3864/j.issn.0578-1752.2019.19.013

Abstract ( 416 )

HTML ( 31 )

PDF (876KB) ( 675 )

Save

Figures and Tables | References | Related Articles | Metrics

Apricot kernel is an excellent pharmaceutical and food resource, with high values of nutrition and commercial utilization. Recently, apricot kernel and its products are increasingly important in demand in the market, while about 80% of the total productions of apricot kernels are sold in the form of raw materials, and the highly value-added priority was not reflected by processing. The main reasons are that the industrial concentration of factories is lower, the amounts of large-scale companies are small, and the technology employed in the companies falls behind, which results in the lowly integrated utilization and lowly added value of the products from the apricot kernels, as well as great loss of some important constituents and pollution to the environment. Thus, it is significant and emergent to efficiently achieve the comprehensive utilization of the apricot kernels with the modern processing technology, to reduce the waste of apricot kernels resources and to improve its added value of products. Based on the literature available, the status and problems occurring were firstly reviewed about the skin-removing, debitterizing and drying of the apricot kernels in this paper. Afterwards, the summaries were concluded on the extraction and purification of the oils, essential oils, proteins and amygdalin of the apricot kernels, especially for the comparison of the advantages and disadvantages of the methods employed and the status of the products being developed from the components of apricot kernels, and then some suggestions were also put forward. All these contents would provide the theoretical basis and technical support for the comprehensive utilization of the apricot kernels and promote its added value, hence achieving a good development of the apricot kernels industry in China. Finally, the solutions and outlook were also made about the key technologies restricting the deeply processing of apricot kernels. To be specific, the first suggestion was that the modern green skin-removing technology should be adopted to replace the traditionally boiling-water blanching method, and to strengthen the efficient recycling and utilization of the active ingredients in water of blanching and the development of the removed skins for some highly value-added products. Secondly, some novel techniques including ultrasonically-accelerated debitterizing, etc should be employed in the debitterizing of apricot kernels, so as to reduce the nutrient loss and the discharge of wastewater during the debitterizing processing. Thirdly, the innovation should be strengthened about the technology of the simultaneous extraction and utilization of the main components of apricot kernels and its practice, by which the oils could be effectively extracted, and the activity of beta-glucosidase, the denaturation of the proteins and the degradation of amygdalin could also be inhibited and not influenced, so as to maximize the comprehensive utilization of apricot kernels. In a word, the research about the processing of apricot kernels should be centered on the recycling of the by-products and the development of some novel highly value-added products from apricot kernels, and the integration degree should also be improved about the industries of apricot kernels, hence raising the market value and the economic benefits of the apricot kernels. All these contents would promote the well development of the apricot kernels industry, and which was also the meaning and purpose of this paper.

Analysis of Volatile Components in Cerasus Humilis (Bge.) Sok by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry

LI XiaoYing,WANG HaiJing,XU NingWei,CAO CuiLing,LIU JianZhen,WU ChunCheng,ZHANG LiBin

Scientia Agricultura Sinica. 2019, 52(19): 3448-3459. doi:10.3864/j.issn.0578-1752.2019.19.014

Abstract ( 383 )

HTML ( 44 )

PDF (569KB) ( 232 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The objective of this study was to optimize the pretreatment conditions and to analyze the volatiles of Cerasus Humilis (Bge.) Sok, further to evaluate the characteristics of the main aroma components.【Method】 The fruit of Cerasus humilis (Bge.) Sok was used as material, the volatiles were determined by headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and the pretreatment conditions were optimized. Automatic Mass Spectral Deconvolution and Identification System (AMDIS), NIST11 database and retention index (RI) were applied to volatiles identify, internal standard to contents calculate, final the odor-activity values (OAVs) and aroma qualities were evaluated.【Result】 Total of 63 volatiles were identified, namely main of esters and alkanes, few of alcohols, arenes, aldehydes, terpenes, acid and ketone, with ranges from 0.01 to 3.25 μg·kg ^-1, in which ethyl benzoate as the highest. The OAVs showed ethyl hexanoate, phenethyl acetate, β-linalool, hexyl acetate, and nonanal were the main aroma components, alkanes almost the odorless. Green, fruity, floral, waxy and less woody and oily aromatic formed the odor qualities, while the former three performed the main odors reached 80% content. 【Conclusion】 The conditions were optimized as follows: samples loading for 5 g after cored and chipping, extraction temperature was 50℃, and both extraction and balance time was 30 min. The pretreatment had great influence on the volatiles detection, and preferable results would be yield by optimizing conditions. Results showed esters were the main components, except alkanes, and the most of them had aroma characteristics, presented medium or high strength, while green, fruity, floral were the major odor types.

Effects of Weaning Age and Dietary Nutritional Levels on Intestinal Morphology and Activity of Digestive Enzymes in 6-Month-Old Shaanbei White Cashmere Goats

QU XingMei,XUE FuLai,HUANG XiaoYu,ZHANG Yu,XING XiaoNan,ZHANG EnPing

Scientia Agricultura Sinica. 2019, 52(19): 3460-3470. doi:10.3864/j.issn.0578-1752.2019.19.015

Abstract ( 227 )

HTML ( 32 )

PDF (533KB) ( 280 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 This study aimed to investigate the effects of weaning age and dietary nutritional levels on intestinal morphology and activity of major digestive enzymes of 6-month-old Shaanbei white Cashmere goats.【Method】 Fifty-four Shaanbei White Cashmere female goats aged 54 days (live body weight was (10.73±1.03)kg) were randomly assigned to 6 groups, with 3 replications per group and 3 goats per replication. Group I, II, and III were fed standard diets, and the weaning age was 90 d, 75 d and 60 d, respectively. Goats in group IV, V and VI were all weaned at 60 d, and were fed diet with 85%, 115%, 130% digestive energy and protein levels of the standard diets, resptectively. Goats were fed to 6-month-old. At the end of the trial period, 1 goat were randomly selected from each replicate for slaughter (no fasting before slaughter), and 2 cm ² tissue samples were collected from upper middle section of duodenum, middle jejunum and distal ileum, respectively. Paraffin sections of sampling tissues were made to observe the morphology of the small intestine. Chyme from each segment of the small intestine was collected for the determination of the enzymes activity of trypsin, chymotrypsin, lipase, alpha-amylase, sucrase and maltase.【Result】 The results showed that: (1) Weaning age affected growth performance of lamb in 4-6 month. The lamb average daily gain of group Ⅲ was significantly greater than that of groupⅠ(P＜0.05). (2) Weaning age affected small intestine histological morphology of 6- month-old lambs. Muscular layer thickness of duodenum and villi surface area of jejunum of group Ⅲ was significantly greater than that of group I or group II (P＜0.05);the villi width of duodenum and the villi width of ileum groupII and group III was significantly higher than that of group I (P＜0.05). (3) weaning age affected the activity of digestive enzymes in small intestine. The activity of lipase in duodenum and ileum, the activity of chymotrypsin in jejunum and ileum, group III was significantly higher than that of groupI or group II (P＜0.05). (4) Nutrient level of diets affected small intestine histological morphology of 6-month-old lambs. The villi height, villi width, muscle layer thickness and villi surface area of duodenum, and the villi height, muscle layer thickness of jejunum, and the villi height, ratio of V/C, groupV and group VI was significantly higher than that of group III and group IV (P＜0.01). (5) Nutrient level of diets affected the activity of digestive enzymes in small intestine. The activity of chymotrypsin and trypsase in jejunum of group V and group VI was significantly higher than that of group III and group IV (P＜0.05); the activity of chymotrypsin in jejunum and the activity of trypsase in ileum of group V was significantly higher than that of each other group (P＜0.05). 【Conclusion】 In this study, in terms of growth performance, small intestine morphology and activity of main digestive enzymes in Shaanbei white Cashmere goat, the best weaning time of lamb was at 60 d, and the optimum dietary energy and protein level was recommended to use 1.15 times the setting standard.

Construction of Co-expression Network of lncRNA and mRNA Related to Hair Follicle Development of Subo Merino Sheep

CHEN HuaFeng,TIAN KeChuan,HUANG XiXia,Ablat Sulayman,HE JunMin,TIAN YueZhen,XU XinMing,FU XueFeng,ZHAO BingRu,ZHU Hua,Hanikezi Tulafu

Scientia Agricultura Sinica. 2019, 52(19): 3471-3484. doi:10.3864/j.issn.0578-1752.2019.19.016

Abstract ( 505 )

HTML ( 32 )

PDF (5017KB) ( 244 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 With the development and improvement of high-throughput sequencing technology, massive transcriptome sequencing data has emerged, and more and more methods of gene network have been used in research; the hair follicles development of fine wool sheep is regulated by multiple genes and lncRNAs. It is not enough to study a certain molecule alone to discover its regulatory mechanism. The aim of this study was to construct a co-expression network of lncRNAs and mRNAs related to hair follicle development, and to explore potential candidate genes for hair follicle development. 【Method】 The study was performed on fetal skin tissues of the 65th, 85th, 105th, and 135th days and lambs skin tissues of the 7th and 30th days from Subo Merino sheep, with 3 biological replicates in each period, a total of 18 samples were sequenced by transcriptome to obtain lncRNAs and mRNAs expression profiles of 6 different developmental stages, and the differential expressed lncRNAs and mRNAs in adjacent periods was screened to construct a co-expression module by Weighted Gene Co-expression Network Analysis (WGCNA) method, and GO (Gene Ontology) and KEGG pathway enrichment analysis of DAVID online tool was used to find hair follicle related modules. Finally, the high-interconnect lncRNAs and mRNAs were screened from the target module for network visualization using Cytoscape software.【Result】 From the expression profile data, 9070 differentially expressed lncRNAs and mRNAs were screened, and 11 modules were obtained by WGCNA method. The DAVID enrichment analysis revealed that the genes in the honeydew1 module, paleturquoise module, and skyblue2 module were involved in biological processes such as skin development, hair follicle development, hair follicle morphogenesis, negative regulation of Wnt signaling pathway, and cell adhesion, et al; and the signaling pathways involved in hair follicle development such as Wnt signaling pathway, TGF-β signaling pathway, Hedgehog signaling pathway, tight junction, MAPK signaling pathway, ECM-receptor interaction, et al. The sub-networks of lncRNAs and mRNAs with high connectivity were screened in these 3 modules, and the hair follicle development related genes including TGFB2, CTSB, SFN, SPINT1, FAM83G, GSDMA, MPZL3, VIM and CRABP1 were obtained, and possible target genes of 24 lncRNAs including ENSOART00000029117, TCONS_00489976, TCONS_00376759 were predicted.【Conclusion】 In this study, we first constructed a co-expression network of lncRNAs and mRNAs related to the hair follicles development of Subo merino sheep using WGCNA method, identified 3 co-expression modules related to hair follicle development, and found several potential candidate genes related to hair follicle development, and predicted possible target genes of 24 lncRNAs.

Biological Characteristics of Transcriptional Regulator GalR in Streptococcus suis Serotype 4

SUN Ke,ZHU HaoDan,HE KongWang,WANG DanDan,ZHOU JunMing,YU ZhengYu,Lü LiXin,NI YanXiu

Scientia Agricultura Sinica. 2019, 52(19): 3485-3494. doi:10.3864/j.issn.0578-1752.2019.19.017

Abstract ( 272 )

HTML ( 18 )

PDF (793KB) ( 277 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The study was carried out to investigate the effect of the deletion of the transcriptional regulator GalR gene of Streptococcus suis type 4 virulent strain SH1510 on the biological characteristics of bacteria in order to further study GalR regulation of galactose metabolism pathway and its pathogenesis, so as to provide a theoretical basis.【Method】 The SH1510ΔGalR, an SS4 virulent strain SH1510 transcriptional regulator GalR gene deletion strain, was constructed by homologous recombination double-crossover. Then, a preliminary screening of the deletion strain was performed by the internal amplification primers I1/I2 of GalR gene, and further identified the deletion strain SH1510ΔGalR by PCR and Western blotting. We performed Gram staining on the parental strain SH1510 and the deletion strain SH1510ΔGalR to compare morphological differences. We configured the basal medium, added glucose, sucrose and D-galactose to culture the bacteria, and plotted the bacterial growth curve to compare the bacteria’s utilization of different sugars. The bacterial concentration of the parent strain and the deletion strain were adjusted to 2.5×10 ⁹ CFU/mL, 5×10 ⁸ CFU/mL, 1×10 ⁸ CFU/mL and 2×10 ⁷ CFU/mL, respectively, and BALB/c mice were intraperitoneally injected. Then, the lethality of the mice was observed, and the strain LD₅₀ was calculated by using the Reed-Muench method. The parental strain and the deletion strain with a concentration of 2×10 ⁷CFU/mL were mixed in an equal volume of 1﹕1 and intraperitoneally injected into BALB/c mice. After 24 h, brain, spleen and blood were counted on chloramphenicol-resistant and non-resistant THB plates to compare the colonization ability of bacteria in mice. The internal environment with the whole blood of healthy pigs was simulated, and then the parent strain and the deletion strain were separately and added to whole blood of healthy pigs containing SS4 antiserum, and incubated at 37℃ for 2 h for plate counting to compare the viability of bacteria in whole blood.【Result】 PCR was performed by using the internal detection primer I1/I2, and the result showed that the deletion strain SH1510ΔGalR was negative. Further, primers C1/C2, O1/C2, O2/C1, and O1/O2 were used to identify the deletion strain SH1510ΔGalR, and 1 056, 2 121, 2 094, and 3 147 bp fragments were amplified, respectively, and the results were in agreement with expectations. The results of Western blotting showed that the parental strain SH1510 could specifically bind to the crude rabbit anti-GalR polyclonal serum, and a single band appeared at 37 kD, but the deletion strain SH1510ΔGalR showed no band. The results of PCR and Western blotting indicated that the deletion strain SH1510ΔGalR was successfully constructed. The parent strain and the deletion strain were stained by Gram. The optical microscopic observation showed that the parent strain and the deletion strain were arranged in a chain, the length was similar, and the morphology was not significantly different. Under the growth conditions of glucose and sucrose as the sole glycogen, the growth of the parent strain and the deletion strain was similar; when the glycogen was D-galactose, the growth rate and OD₆₀₀ value of the deletion strain were significantly lower than that of the parent strain. In addition, it could be seen from the highest OD₆₀₀value that the utilization rate of sugar by Streptococcus suis SH1510 was glucose>sucrose>D-galactose. In the mouse pathogenicity test, the LD₅₀ of the parent strain and the deletion strain were 1×10 ⁸ CFU and 1.62×10 ⁸ CFU, respectively, and the pathogenicity of the deletion strain to the mouse was decreased by 1.62 times. In vivo competitive infection test results showed that the number of bacteria isolated from deleted strains in the brain, spleen and blood of the mice was much lower than that of the parent strains, and the difference was extremely significant (P＜0.01). The whole blood survival test showed that the survival rate of the parent strain was 35.2%, the survival rate of the deletion strain was 27.3%, and the survival rate of the deletion strain SH1510ΔGalR in the whole blood was significantly lower than that of the parent strain SH1510 (P＜0.05).【Conclusion】 In summary, the GalR gene could promote the utilization of galactose by Streptococcus suis serotype 4, and had direct or indirect regulation of the virulence of SH1510.

Table of Content