Effects of LPA on the development of sheep in vitro fertilized embryos and attempt to establish sheep embryonic stem cells

Lysophosphatidic acid (LPA) is a small molecule glycerophospholipid, which regulates multiple downstream signalling pathways through G-protein-coupled receptors to achieve numerous functions on oocyte maturation and embryo development.  In this study, sheep in vitro fertilized embryos were applied to investigate the effects of LPA on early embryos development and embryonic stem cell establishment.  At first, the maturation medium containing estrus female sheep serum and synthetic oviduct fluid (SOF) were optimized for sheep IVF, and then the effects of LPA were investigated.  From 0.1 to 10 μmol L^–1, LPA had no significant effect on the cleavage rate (P>0.05), but the maturation rate and blastocyst rate increased dependently with LPA concentration (P<0.05), and the blastocyst morphology was normal.  When the LPA concentration was 15 μmol L^–1, the maturation rate, cleavage rate and blastocyst rate decreased significantly (P<0.05), and the blastocyst exhibited abnormal morphology and could not develop into high-quality blastocyst.  Besides, the exogenous LPA increases the expression of LPAR2, LPAR4, TE-related gene CDX-2 and pluripotency-related gene OCT-4 in sheep early IVF embryos with the raise of LPA concentration from 0.1 to 10 μmol L^–1.  The expression of LPAR2, LPAR4, CDX-2 and OCT-4 from the LPA-0.1 μmol L^–1 to LPA-10 μmol L^–1 groups in early embryos were extremely significant (P<0.05), while the expression of these genes significantly decreased in 15 μmol L^–1 LPA-treated embryos compared with LPA-10 μmol L^–1 group (P<0.05).  The inner cell mass in 15 μmol L^–1 LPA-treated embryos was also disturbed, and the blastocysts formation was abnormal.  Secondly, the sheep IVF blastocysts were applied to establish embryonic stem cells.  The results showed that LPA made the blastocyst inoculated cells grow towards TSC-like cells.  They enhanced the fluorescence intensity and mRNA abundance of OCT-4 and CDX-2 as the concentration increased from 0 to 10 μmol L^–1, while 15 μmol L^–1 LPA decreased OCT-4 and CDX-2 expression in the derived cells.  The expression of CDX-2 and OCT-4 in the blastocyst inoculated cells of LPA-1 μmol L^–1 group and LPA-10 μmol L^–1 group extremely significantly increased (P<0.05), but there was significant decrease in LPA-15 μmol L^–1 group compared with LPA-10 μmol L^–1 group (P<0.05).  Meanwhile, the protein expression of LPAR2 and LPAR4 remarkably increased after treatment of LPA at 10 μmol L^–1 concentration.  This study references the IVF embryo production and embryonic stem cell research of domestic animals.      

Nonphytotoxic copper oxide nanoparticles are powerful “nanoweapons” that trigger resistance in tobacco against the soil-borne fungal pathogen Phytophthora nicotianae

Investigations into the potential application of nanoparticles acting as nanofungicides in sustainable agriculture are rapidly expanding due to the high antimicrobial properties of these compounds, which do not risk inducing pathogen resistance to fungicides.  A detailed understanding of the impact of copper oxide nanoparticles (CuO NPs) on soil-borne phytopathogenic fungi is yet to be obtained.  This study aimed to explore the in vitro antifungal activity and control efficacy of CuO NPs applied via irrigation with respect to tobacco black shank (TBS) disease caused by Phytophthora nicotianae.  The results revealed that CuO NPs greatly interfered with the reproductive growth process of this fungus, repressing hyphal growth, spore germination and sporangium production.  Additionally, morphological damage, intracellular ROS accumulation and increased SOD enzyme activity in hyphae were the antifungicidal mechanisms of these NPs.  In pot experiments, treatment with CuO NPs at 100 mg L^–1 significantly suppressed TBS development, compared with the effect on control plants, and the control efficacy reached 33.69% without inducing phytotoxicity.  Exposure to CuO NPs significantly activated a series of defense enzymes, and resistance genes in tobacco can further explain the mechanisms by which CuO NPs suppressed fungal infection.  The Cu content in both the leaves and roots of P. nicotianae-infested plants increased by 50.03 and 27.25%, respectively, after treatment with 100 mg L^–1 CuO NPs, compared with that of healthy plants.  In particular, a higher Cu content was observed in infected roots than in leaves.  Therefore, this study showed the potential of CuO NPs applied as nanofungicides and as nanoinducers of fungus resistance genes for the management of TBS through inhibition of pathogen infection and stimulation of plant defenses.     

Investigation of Aegilopsumbellulatafor stripe rust resistance,heading date,and the contents of iron,zinc, and gluten protein

Aegilops umbellulata (UU) is a wheat wild relative that has potential use in the genetic improvement of wheat.  In this study, 46 Ae. umbellulata accessions were investigated for stripe rust resistance, heading date (HD), and the contents of iron (Fe), zinc (Zn), and seed gluten proteins.  Forty-two of the accessions were classified as resistant to stripe rust, while the other four accessions were classified as susceptible to stripe rust in four environments.  The average HD of Ae. umbellulata was significantly longer than that of three common wheat cultivars (180.9 d vs. 137.0 d), with the exception of PI226500 (138.9 d).  The Ae. umbellulata accessions also showed high variability in Fe (69.74–348.09 mg kg^–1) and Zn (49.83–101.65 mg kg^–1) contents. Three accessions (viz., PI542362, PI542363, and PI554399) showed relatively higher Fe (230.96–348.09 mg kg^–1) and Zn (92.46–101.65 mg kg^–1) contents than the others.  The Fe content of Ae. umbellulata was similar to those of Ae. comosa and Ae. markgrafii but higher than those of Ae. tauschii and common wheat.  Aegilops umbellulata showed a higher Zn content than Ae. tauschii, Ae. comosa, and common wheat, but a lower content than Ae. markgrafii.  Furthermore, Ae. umbellulata had the highest proportion of γ-gliadin among all the species investigated (Ae. umbellulata vs. other species=mean 72.11% vs. 49.37%; range: 55.33–86.99% vs. 29.60–67.91%).  These results demonstrated that Ae. umbellulata exhibits great diversity in the investigated traits, so it can provide a potential gene pool for the genetic improvement of these traits in wheat.     

Biosynthesis of artemisinic acid in engineered Saccharomyces cerevisiae and its attractiveness to the mirid bug Apolygus lucorum

Artemisia annua is an important preferred host of the mirid bug Apolygus lucorum in autumn.  Volatiles emitted from A. annua attract A. lucorum.  Volatile artemisinic acid of A. annua is a precursor of artemisinin that has been widely investigated in the Chinese herbal medicine field.  However, little is known at this point about the biological roles of artemisinic acid in regulating the behavioral trends of A. lucorum.  In this study, we collected volatiles from A. annua at the seedling stage by using headspace solid phase microextraction (HS-SPME).  Gas chromatography-mass spectrometry (GC-MS) analysis showed that approximately 11.03±6.00 and 238.25±121.67 ng h^–1 artemisinic acid were detected in volatile samples and milled samples, respectively.  Subsequently, a key gene for artemisinic acid synthesis, the cytochrome P450 gene cyp71av1, was expressed in engineered Saccharomyces cerevisiae to catalyze the production of artemisinic acid.  After the addition of exogenous artemisinic alcohol or artemisinic aldehyde, artemisinic acid was identified as the product of the expressed gene.  In electroantennogram (EAG) recordings, 3-day-old adult A. lucorum showed significant electrophysiological responses to artemisinic alcohol, artemisinic aldehyde and artemisinic acid.  Furthermore, 3-day-old female bugs were significantly attracted by artemisinic acid and artemisinic alcohol at a concentration of 10 mmol L^–1, whereas 3-day-old male bugs were attracted significantly by 10 mmol L^–1 artemisinic acid and artemisinic aldehyde.  We propose that artemisinic acid and its precursors could be used as potential attractant components for the design of novel integrated pest management strategies to control A. lucorum.     

Establishment of an efficient regeneration and genetic transformation system for Malus prunifolia Borkh. ‘Fupingqiuzi’

Malus prunifolia Borkh. ‘Fupingqiuzi’ has significant ecological and economic value and plays a key role in germplasm development and resistance research.  However, its long juvenile phase and high heterozygosity are barriers to the identification of ‘Fupingqiuzi’ progeny with excellent traits.  In-vitro regeneration techniques and Agrobacterium-mediated genetic transformation systems can efficiently produce complete plants and thus enable studies of gene function.  However, optimal regeneration and genetic transformation systems for ‘Fupingqiuzi’ have not yet been developed.  Here, we evaluated the factors that affect the in-vitro regeneration and transformation of ‘Fupingqiuzi’.  The best results were obtained when transverse leaf sections were used as explants, and they were grown in dark culture for three weeks with their adaxial sides contacting the culture medium (MS basal salts, 30 g L⁻¹ sucrose, 8 g L⁻¹ agar, 5 mg L⁻¹  6-benzylaminopurine (6-BA), 2 mg L⁻¹ thidiazuron (TDZ), and 1 mg L⁻¹ 1-naphthlcetic acid (NAA), pH 5.8).  A genetic transformation system based on this regeneration system was optimized: after inoculation with A. tumefaciens solution for 8 min, 4 days of co-culture, and 3 days of delayed culture, the cultures were screened with cefotaxime (150 mg L⁻¹) and kanamycin (15 mg L⁻¹).  We thus established an efficient regeneration and genetic transformation system for ‘Fupingqiuzi’, enabling the rapid production of transgenic material.  These findings make a significant contribution to apple biology research     

In vitro and in silico studies of salicylic acid on systemic induced resistance against bacterial leaf blight disease and enhancement of crop yield

Salicylic acid (SA) is an effective elicitor to promote plant defenses and growth.This study aimed to investigate rice(Oryza sativa L.) cv.Khao Dawk Mali 105 treated with salicylic acid (SA)-Ricemate as an enhanced plant protection mechanism against bacterial leaf blight (BLB) disease caused by Xanthomonas oryzae pv.oryzae (Xoo).Results indicated that the use of SA-Ricemate as a foliar spray at concentrations of more than 100 mg L^–1 can reduce the severity of BLB disease by 71%.SA-Ric...     

Quantifying in situ N2 fluxes from an intensively managed calcareous soil using the 15N gas-flux method

Denitrification-induced nitrogen (N) losses from croplands may be greatly increased by intensive fertilization.  However, the accurate quantification of these losses is still challenging due to insufficient available in situ measurements of soil dinitrogen (N₂) emissions.  We carried out two one-week experiments in a maize–wheat cropping system with calcareous soil using the ¹⁵N gas-flux (¹⁵NGF) method to measure in situ N₂ fluxes following urea application.  Applications of ¹⁵N-labeled urea (99 atom%, 130–150 kg N ha⁻¹) were followed by irrigation on the 1st, 3rd, and 5th days after fertilization (DAF 1, 3, and 5, respectively).  The detection limits of the soil N₂ fluxes were 163–1 565, 81–485, and 54–281 μg N m⁻² h⁻¹ for the two-, four-, and six-hour static chamber enclosures, respectively.  The N₂ fluxes measured in 120 cases varied between 159 and 2 943 (811 on average) μg N m⁻² h⁻¹, which were higher than the detection limits, with the exception of only two cases.  The N₂ fluxes at DAF 3 were significantly higher (by nearly 80% (P<0.01)) than those at DAF 1 and 5 in the maize experiment, while there were no significant differences among the irrigation times in the wheat experiment.  The N₂ fluxes and the ratios of nitrous oxide (N₂O) to the N₂O plus N₂ fluxes following urea application to maize were approximately 65% and 11 times larger, respectively (P<0.01), than those following urea application to wheat.  Such differences could be mainly attributed to the higher soil water contents, temperatures, and availability of soil N substrates in the maize experiment than in the wheat experiment.  This study suggests that the ¹⁵NGF method is sensitive enough to measure in situ N₂ fluxes from intensively fertilized croplands with calcareous soils.     

Expression profiling of transgenes (Cry1Ac and Cry2A) in cotton genotypes under different genetic backgrounds

Transgenic cotton carrying the Cry1Ac gene has revolutionized insect pest control since its adoption, although the development of resistance in insect pests has reduced its efficacy.  After 10 years of cultivating Bacillus thuringiensis (Bt) cotton with a single Cry1Ac gene, growers are on the verge of adopting Bt cotton that carries the double gene (Cry1Ac+Cry2A) due to its better effectiveness against insect pests.  Thus, the current study was designed to evaluate the role of each gene in the effectiveness of Bt cotton carrying the double gene.  The expression levels of the Cry1Ac and Cry2A genes were evaluated in the leaves of 10 genotypes (2 parents and 8 F₁ hybrids) at 30 days after sowing (DAS), while samples of leaves, bolls and flowers were taken from the upper and lower canopies at 70 and 110 DAS.  The F₁ hybrids were developed through reciprocal crosses between two Bt (CKC-1, CKC-2) and two non-Bt (MNH-786, FH-942) parents.  The differential expression of transgenes was evaluated through Enzyme Linked Immuno-Sorbent Assay (ELISA).  The results showed that the MNH786×CKC-1 hybrid had the highest concentrations of Cry1Ac gene at 30 DAS (3.08 µg g^–1) and 110 DAS (1.01 µg g^–1) in leaves.  In contrast, the CKC-2×MNH-786 hybrid showed the lowest concentrations of Cry1Ac gene at 30 DAS (2.30 µg g^–1) and 110 DAS (0.86 µg g^–1).  The F₁ hybrid FH-942×CKC-2 showed the highest concentrations of Cry2A gene at 30 DAS (8.39 µg g^–1) and 110 DAS (7.74 µg g^–1) in leaves, while the CKC-1×MNH-786 hybrid expressed the lowest concentrations of Cry2A gene at 30 DAS (7.10 µg g^–1) and 110 DAS (8.31 µg g^–1).  A comparison between the two stages of plant growth showed that leaves had the highest concentrations at 30 DAS, whereas the lowest concentrations were observed at 110 DAS for both genes in leaves.  When the expression pattern was compared between various plant parts in genotype CKC-2, it was found that leaves had higher concentrations of Cry1Ac (3.12 µg g^–1) and Cry2A (8.31 µg g^–1) at 70 DAS, followed by bolls (Cry1Ac (1.66 µg g^–1) and Cry2A (8.15 µg g^–1)) and flowers (Cry1Ac (1.07 µg g^–1) and Cry2A (7.99 µg g^–1)).  The genotype CKC-2 had higher concentrations of Cry1Ac (3.12 µg g^–1) and Cry2A (8.31 µg g^–1) in the upper canopy but less accumulation (2.66 µg g^–1 of Cry1Ac, 8.09 µg g^–1 of Cry2A) in the lower canopy at 70 DAS.  Similarly, at 110 DAS, the expression levels of Cry1Ac and Cry2A in upper and lower canopy leaves were 1.52 and 7.92 µg g^–1, and 0.99 and 7.54 µg g^–1, respectively.  Hence, the current study demonstrates that different genotypes showed variable expression for both of the Cry1Ac and Cry2A genes during plant growth due to different genetic backgrounds.  The Cry2A gene had three-fold higher expression than Cry1Ac with significant differences in expression in different plant parts.  The findings of this study will be helpful for breeding insect-resistant double-gene genotypes with better gene expression levels of Cry1Ac and Cry2A for sustainable cotton production worldwide.     

Dietary copper supplementation modulates performance and lipid metabolism in meat goat kids

Forty-eight male Lezhi black goat kids with similar body weight ((12.09±1.70) kg) and age ((60±5) d) were used to determine the effect of dietary copper (Cu), in the form of reagent grade Cu sulfate (CuSO₄∙5H₂O), on performance, serum lipid profile, and the relative mRNA abundance of genes involved in lipid metabolism.  Goat kids were stratified by body weight and randomly assigned to one of 4 treatment groups.  Each treatment consisted of 12 replicate pens with each pen containing one goat kid.  Treatment groups received the basal diet with no supplemental Cu (control), basal diet plus 10 mg of Cu kg^–1 of dry matter (DM), basal diet plus 20 mg of Cu kg^–1 of DM, or basal diet plus 30 mg of Cu kg^–1 of DM.  Goats were housed individually in pens and fed a high-concentrate pelleted diet for 60 d.  Average daily gain, average daily feed intake and feed:gain of goats were not affected by dietary Cu supplementation (P>0.10).  No differences were detected in serum total cholesterol, triglyceride, and high density lipoprotein cholesterol concentrations of goat kids fed with different Cu concentrations (P>0.05).  However, serum low density lipoprotein cholesterol concentrations decreased linearly (P=0.01) as the concentration of dietary Cu increased.  Intramuscular fat content of longissimus muscle increased (P=0.002) quadratically and liver Cu concentrations increased (P<0.001) linearly as dietary Cu concentration increased.  Compared with the control, dietary supplementation of 20 mg Cu kg^–1 DM decreased the relative mRNA abundance of fatty acid-binding protein 4 (P=0.01) and lipoprotein lipase (P=0.05), and tended to decrease the relative mRNA abundance of carnitine palmitoyltransferase I (P=0.06) in longissimus muscle of goats.  The relative mRNA abundance of peroxisome proliferator-activated receptor alpha (P<0.001), carnitine acetyltransferase (P=0.001), and carnitine palmitoyltransferase I (P=0.001) were also decreased in liver by Cu supplementation.  These results indicate that dietary supplementation of Cu modified lipid metabolism by increasing muscular fat and decreasing serum low density lipoprotein cholesterol, and the modification might be associated with the reduction of relative mRNA abundance of genes for oxidation of long-chain fatty acid in muscle and liver of Lezhi black goat kids.     

dep1 improves rice grain yield and nitrogen use efficiency simultaneously by enhancing nitrogen and dry matter translocation

The rice cultivars carrying dep1 (dense and erect panicle 1) have the potential to achieve both high grain yield and high nitrogen use efficiency (NUE).  However, few studies have focused on the agronomic and physiological performance of those cultivars associated with high yield and high NUE under field conditions.  Therefore, we evaluated the yield performance and NUE of two near-isogenic lines (NILs) carrying DEP1 (NIL-DEP1) and dep1-1 (NIL-dep1) genes under the Nanjing 6 background at 0 and 120 kg N ha^–1.  Grain yield and NUE for grain production (NUEg) were 25.5 and 21.9% higher in NIL-dep1 compared to NIL-DEP1 averaged across N treatments and planting years, respectively.  The yield advantage of NIL-dep1 over NIL-DEP1 was mainly due to larger sink size (i.e., higher total spikelet number), grain-filling percentage, total dry matter production, and harvest index.  N utilization rather than N uptake contributed to the high yield of NIL-dep1.  Significantly higher NUEg in NIL-dep1 was associated with higher N and dry matter translocation efficiency, lower leaf and stem N concentration at maturity, and higher glutamine synthetase (GS) activity in leaves.  In conclusion, dep1 improved grain yield and NUE by increasing N and dry matter transport due to higher leaf GS activity under field conditions during the grain-filling period.     

Halloween genes AhCYP307A2 and AhCYP314A1 modulate last instar larva–pupa–adult transition,ovarian development and oogenesis in Agasicles hygrophila(Coleoptera: Chrysomelidae)

Ininsects,ecdysteroidsaresynthesizedbygenesoftheHalloweenfamilyandplayimportantrolesinseveralkey developmentalevents,includingmoltingandmetamorphosis.However,therolesofthesegenesinAgasicles hygrophila are still largely unknown.In this study, the expression patterns of the two Halloween genesAhCYP307A2andAhCYP314A1weredeterminedbyquantitativePCR(qPCR)atdifferentdevelopmentalstages.Moreover,the functions of these two genes were explored using RNA interference (RNAi), and ovarian development was ob...     

Azole selenourea disrupted the midgut and caused malformed development of Plutellaxylostella

Chemical insecticides targeting the digestive system of diamondback moth (DBM), Plutella xylostella, have not been developed.  The discovery of an insecticide with novel mode of action is a challenge for the control of DBM.  In this study, a class of selenium- and difluoromethyl-modified azoles (fluoroazole selenoureas, FASU) were designed and synthesized for the control of DBM.  Of these azoles, compound B4 showed the highest insecticidal activity against DBM.  The LC₅₀ of third- and second-instar larvae reached 32.3 and 4.6 μg mL^–1, respectively.  The midgut tissue of larvae was severely disrupted, and the larval intestinal tissue was dotted with unique red spots after treatment with compound B4.  Compound B4 led to disintegration of the peritrophic matrix, swelling of the midgut epithelium, fracture of the microvilli, and extensive leakage of cellular debris in the midgut lumen.  Surviving larvae grew very slowly, and the larval duration was significantly prolonged after exposure to compound B4 at sublethal doses (LC₁₀, LC₂₅ and LC₅₀).  Furthermore, the pupation rate, emergence rate and pupae weight were significantly decreased.  Compound B4 also induced abnormal pupae, causing adults to be trapped in the cocoon or failure to fly due to twisted wings.  These results demonstrated that FASU could reduce the population of DBM in sublethal doses.  FASU is the first synthetic insecticidal lead compound that has been shown to disrupt the midgut tissue of the larvae of DBM, and its mode of action totally differs from that of commercial chemical insecticides.     

Functional analysis of MdSUT2.1, a plasma membrane sucrose transporter from apple

Sugar content is a determinant of apple(Malus×domestica Borkh.) sweetness. However, the molecular mechanism underlying sucrose accumulation in apple fruit remains elusive. Herein, this study reported the role of the sucrose transporter MdSUT2.1 in the regulation of sucrose accumulation in apples. The MdSUT2.1 gene encoded a protein with 612 amino acid residues that could be localized at the plasma membrane when expressed in tobacco leaf protoplasts.MdSUT2.1 was highly expressed in fruit and was ...     

镉胁迫下黑曲霉TL-F2的促生特征及其对黑麦草种子萌发、幼苗生长和镉含量的影响

以黑曲霉(Aspergillus niger)TL-F2为供试菌株,黑麦草为供试植物,研究Cd胁迫下A. niger TL-F2的促生特性,以及对黑麦草种子萌发、幼苗生长和Cd含量的影响。结果表明:与不加Cd的对照组相比,低浓度Cd(5 mg·L^-1)胁迫下,A. niger TL-F2产吲哚乙酸(IAA)和溶磷的能力无显著变化,但产铁载体的能力显著(P<0.05)降低48.18%;中(20 mg·L^-1)、高(50 mg·L^-1)浓度Cd胁迫下,A. niger TL-F2产IAA的能力分别显著(P<0.05)降低55.76%和65.69%,溶磷量分别显著(P<0.05)降低50.07%和78.19%,产铁载体的能力分别显著(P<0.05)降低69.71%和80.08%。接种高浓度(1×10⁸ mL^-1)A. niger TL-F2有助于促进Cd胁迫下黑麦草种子的萌发和生长,高浓度Cd胁迫下,黑麦草地上部Cd含量较不接菌的显著(P<0.05)增加,增幅为17.95%;接种低浓度(1×10⁶ mL^-1)A. niger TL-F2对黑麦草种子萌发、Cd含量无明显促进作用。综合来看,接种适当量的A. niger TL-F2有助于促进Cd胁迫下黑麦草种子的萌发和生长,增加黑麦草地上部Cd含量,可作为黑麦草修复Cd污染水体和土壤的强化措施。     

Growth and nitrogen productivity of drip-irrigated winter wheat under different nitrogen fertigation strategies in the North China Plain

Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).  Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses, while the performance of drip fertigation in winter wheat is limited by poor N scheduling.  A two-year field experiment was conducted to evaluate the growth, development and yield of drip-fertigated winter wheat under different split urea (46% N, 240 kg ha^–1) applications.  The six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) application.  The five N scheduling treatments were N0–100 (0% at sowing and 100% at jointing/booting), N25–75 (25% at sowing and 75% at jointing and booting), N50–50 (50% at sowing and 50% at jointing/booting), N75–25 (75% at sowing and 25 at jointing/booting), and N100–0 (100% at sowing and 0% at jointing/booting).  The SRF (43% N, 240 kg ha^–1) was only used as fertilizer at sowing.  Split N application significantly (P<0.05) affected wheat grain yield, yield components, aboveground biomass (ABM), water use efficiency (WUE) and nitrogen partial factor productivity (NPFP).  The N50–50 and SRF treatments respectively had the highest yield (8.84 and 8.85 t ha^–1), ABM (20.67 and 20.83 t ha^–1), WUE (2.28 and 2.17 kg m^–3) and NPFP (36.82 and 36.88 kg kg^–1).  This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat crops.  Although the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading, the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.     

大豆异黄酮对早期断奶仔猪生长性能、抗氧化功能及肠粘膜形态结构的影响

【目的】 研究饲粮中添加大豆异黄酮对早期断奶仔猪生长性能和抗氧化作用及免疫功能的影响。【方法】 选用160只5.5 kg 21日龄断奶的（杜×长×大）三元杂交仔猪,根据体重和性别随机分成5组,每组4个重复（公母各4只）。各处理组饲粮大豆异黄酮添加水平分别为0（空白对照组）、10、20、40、80 mg·kg^-1。试猪饲养至7、42d时每个重复分别选取平均体重的试猪屠宰并取样测定。【结果】 断奶后8—42 d和整个试验期阶段,大豆异黄酮40 mg·kg^-1组平均日采食量显著高于空白对照组、10 mg·kg^-1大豆异黄酮组和20 mg·kg^-1大豆异黄酮组（P<0.05）。断奶后8—42 d时,大豆异黄酮20 mg·kg^-1组料重比显著低于空白对照组和80 mg·kg^-1大豆异黄酮组（P<0.05）。断奶后7d,肝脏中丙二醛（MDA）含量随大豆异黄酮添加水平提高有降低的趋势,其中添加大豆异黄酮40和80 mg·kg^-1 组试验猪肝脏中的MDA含量显著低于空白对照组和10 mg·kg^-1 大豆异黄酮组。添加大豆异黄酮20 mg·kg^-1 组仔猪血清超氧化物歧化酶（SOD）活性显著高于空白对照组、40 mg·kg^-1 大豆异黄酮组和80 mg·kg^-1大豆异黄酮组（P<0.05）。添加大豆异黄酮10 mg·kg^-1 组肝脏组织谷胱甘肽过氧化物酶（GSH-Px）活性显著高于对照组和80 mg·kg^-1 大豆异黄酮组（P<0.05）。断奶后8—42 d时,20 mg·kg^-1大豆异黄酮组试验猪料重比显著低于空白对照组和80 mg·kg^-1大豆异黄酮组（P<0.05）。断奶42d时,添加大豆异黄酮40 mg·kg^-1 组血清SOD活性显著高于空白对照组、10 mg·kg^-1 大豆异黄酮组和80 mg·kg^-1大豆异黄酮组（P<0.05）。大豆异黄酮20 mg·kg^-1组肝脏的GSH-Px活性显著高于空白对照组和80 mg·kg^-1 大豆异黄酮组（P<0.05）。断奶后42d,大豆异黄酮40和80 mg·kg^-1组的空肠SOD活性显著高于对照组（P<0.05）;添加大豆异黄酮40 mg·kg^-1组空肠的GSH-Px活性显著高于对照组和10 mg·kg^-1大豆异黄酮组（P<0.05）;饲粮大豆异黄酮对空肠的金属硫蛋白（MT）含量有显著影响作用,其中大豆异黄酮10 mg·kg^-1组空肠的MT含量显著高于空白对照组（P<0.05）。断奶后7、42d对照组仔猪十二指肠绒毛成舌状排列,绒毛顶端凹陷且脱落严重,各处理组与对照组相比,十二指肠绒毛损伤程度降低,其中40 mg·kg^-1组仔猪十二指肠绒毛最完整,成柱状排列。添加大豆异黄酮对断奶仔猪42d的血液中CD4⁺的水平有显著影响作用,对淋巴细胞转化率、CD8⁺、CD4⁺/ CD8⁺无显著影响（P>0.05）,其中大豆异黄酮10和20 mg·kg^-1组血液中CD4⁺水平显著低于空白对照组和80 mg·kg^-1大豆异黄酮组（P<0.05）。【结论】 饲粮中添加大豆异黄酮能够提高断奶仔猪的生长性能,增强机体的抗应激能力,对肠绒毛有一定的保护作用,早期断奶仔猪大豆异黄酮适宜添加量为40mg·kg^-1。     

TIMP2 promotes intramuscular fat deposition by regulating the extracellular matrix in chicken

The interaction between myocytes and intramuscular adipocytes is a hot scientific topic.  Using a co-culture system, this study aims to investigate the regulation of intramuscular fat deposition in chicken muscle tissue through the interaction between myocyte and adipocyte and identify important intermediary regulatory factors.  Our proteomics data showed that the protein expression of tissue inhibitor of metalloproteinases 2 (TIMP2) increased significantly in the culture medium of the co-culture system, and the content of lipid droplets was more in the co-culture intramuscular adipocytes.  In addition, TIMP2 was significantly upregulated (P<0.01) in muscle tissue of individuals with high intramuscular fat content.  Weighted gene co-expression network analysis revealed that TIMP2 was mainly involved in the extracellular matrix receptor interaction signaling pathway and its expression was significantly correlated with triglyceride, intramuscular fat, C14:0, C14:1, C16:0, C16:1, and C18:1n9C levels.  Additionally, TIMP2 was co-expressed with various representative genes related to lipid metabolism (such as ADIPOQ, SCD, ELOVL5, ELOVL7, and LPL), as well as certain genes involved in extracellular matrix receptor interaction (such as COL1A2, COL4A2, COL5A1, COL6A1, and COL6A3), which are also significantly upregulated (P<0.05 or P<0.01) in muscle tissue of individuals with high intramuscular fat content.  Our findings reveal that TIMP2 promotes intramuscular fat deposition in muscle tissue through the extracellular matrix receptor interaction signaling pathway.     

Transcriptional profiling between yellow- and black-seeded Brassica napus reveals molecular modulations on flavonoid and fatty acid content

Brassica napus is an important cash crop broadly grown for the vegetable and oil values.  Yellow-seeded B. napus is preferred by breeders due to its improved oil and protein quality, less pigments and lignin compared with the black-seeded counterpart.  This study compared the differences in flavonoid and fatty acid contents between yellow rapeseed from the progenies of B. napus–Sinapis alba somatic hybrids and the black-seeded counterpart using RNA-seq analysis.  Through HPLC-PDA-ESI(−)/MS² analysis, it was found that phenylpropanoids and flavonoids (i.e., isorhamnetin, epicatechin, kaempferol, and other derivatives) in yellow seed were significantly lower than those in black seed.  The fatty acid (FA) content in yellow rapeseed was higher than that in black rapeseed due to the variation of C16:0, C18:0, C18:1, C18:2, and C18:3 contents.  RNA-seq analysis of seeds at four and five weeks after flowering (WAF) indicated that differentially expressed genes (DEGs) between black and yellow rapeseeds were enriched in flavonoid and FA biosynthesis, including BnTT3, BnTT4, BnTT18, and BnFAD2.  Also, genes related to FA biosynthesis, desaturation and elongation (FAD3, LEC1, FUS3, and LPAT2) in yellow seed were up-regulated compared to those in black seed, while genes involved in beta-oxidation cycle (AIM1 and KAT2) of yellow seed were down-regulated compared to those in black seed.  The DEGs related to the variation of flavonoids, phenylpropanoids, and FAs would help improve the knowledge of yellow seed character in B. napus and promote rapeseed improvement.     

Grain yield,nitrogen use efficiency and physiological performance of indica/japonica hybrid rice in response to various nitrogen rates

Utilizing the heterosis of indica/japonica hybrid rice (IJHR) is an effective way to further increase rice grain yield.Rational application of nitrogen (N) fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield potential.However,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain elusive.The purpose of this study was to clarify these issues.Three rice cultivars currently used...