The accumulation of soil organic carbon (SOC) and total nitrogen (TN) is easily accomplished by returning crop straw, which strongly affects the formation and pore structure of aggregates, especially in black soil.  We returned maize straw at different rates (6,000, 9,000, 12,000 and 15,000 kg ha^–1) for nine years to investigate its influence on the SOC and TN contents in the SOC fractions of aggregates by combining size and density fractionation.  Their subsequent influences on pore morphology and size distribution characteristics were examined using X-ray micro-computed tomography scanning (μCT).  The results showed that returning straw significantly increased the contents of C and N in the SOC fractions of aggregates, especially at the return rates of 12,000 and 15,000 kg ha^–1, which in turn promoted aggregate formation and stability, and ultimately amended pore structure.  The pore size>100 μm, porosity (>2 μm), and morphological characteristics (anisotropy, circularity, connectivity and fractal dimension) significantly increased, but the total number of pores significantly decreased (P<0.05).  Our results indicated that the amendment of the pore morphology and size distribution of soil aggregates was primarily controlled by the higher contents of C and N in the density fractions of aggregates, rather than in the aggregate sizes.  Furthermore, this pore network reconfiguration favored the storage of C and N simultaneously.  The findings of this study offer valuable new insights into the relationships between C and N storage and the pore characteristics in soil aggregates under straw return. 

High-molecular-weight glutenin subunits (HMW-GSs) are the most critical grain storage proteins that determine the unique processing qualities of wheat. Although it is a part of the superior HMW-GS pair (Dx5+Dy10), the contribution of the Dy10 subunit to wheat processing quality remains unclear. In this study, we elucidated the effect of Dy10 on wheat processing quality by generating and analyzing a deletion mutant (with the Dy10-null allele), and by elucidating the changes to wheat flour following the incorporation of purified Dy10. The Dy10-null allele was transcribed normally, but the Dy10 subunit was lacking. These findings implied that the Dy10-null allele reduced the glutenin:gliadin ratio and negatively affected dough strength (i.e., Zeleny sedimentation value, gluten index, and dough development and stability times) and the bread-making quality; however, it positively affected the biscuit-making quality. The incorporation of various amounts of purified Dy10 into wheat flour had a detrimental effect on biscuit-making quality. The results of this study demonstrate that the Dy10 subunit is essential for maintaining wheat dough strength. Furthermore, the Dy10-null allele may be exploited by soft wheat breeding programs.

As intracellular fatty acid (FA) carriers, FA-binding proteins (FABPs) widely participate in the absorption, transport, and metabolism of FAs.  It is a key protein in insect lipid metabolism and plays an important role in various physiological activities of insects.  An FABP gene (HvFABP) was cloned from the transcriptional library of Heortia vitessoides Moore (Lepidoptera: Crambidae), and its expression patterns were determined using reverse transcription quantitative PCR (RT-qPCR).  Stage- and tissue-specific expression profiles indicated that HvFABP highly expressed from prepupal to adult stages and in larval midgut and adult wings.  HvFABP expression may be induced through starvation, mRNA expression was downregulated at 24 and 48 h and upregulated at 72 h after starvation.  Furthermore, 20-hydroxyecdysone can induce the upregulation of its expression.  RNA interference-mediated silencing of HvFABP significantly inhibited HvFABP expression, resulting in delayed development, abnormal molting or lethal phenotypes, and a significantly reduced survival rate.  These results indicate that HvFABP plays a key role in the molting of H. vitessoides

Soybean is one of the most important food crops worldwide.  Like other legumes, soybean can form symbiotic relationships with Rhizobium species.  Nitrogen fixation of soybean via its symbiosis with Rhizobium is pivotal for sustainable agriculture.  Type III effectors (T3Es) are essential regulators of the establishment of the symbiosis, and nodule number is a feature of nitrogen-affected nodulation.  However, genes encoding T3Es at quantitative trait loci (QTLs) related to nodulation have rarely been identified. Chromosome segment substitution lines (CSSLs) have a common genetic background but only a few loci with heterogeneous genetic information; thus, they are suitable materials for identifying candidate genes at a target locus.  In this study, a CSSL population was used to identify the QTLs related to nodule number in soybean.  Single nucleotide polymorphism (SNP) markers and candidate genes within the QTLs interval were detected, and it was determined which genes showed differential expression between isolines.  Four candidate genes (GmCDPK28, GmNAC1, GmbHLH, and GmERF5) linked to the SNPs were identified as being related to nodule traits and pivotal processes and pathways involved in symbiosis establishment.  A candidate gene (GmERF5) encoding a transcription factor that may interact directly with the T3E NopAA was identified.  The confirmed CSSLs with important segments and candidate genes identified in this study are valuable resources for further studies on the genetic network and T3Es involved in the signaling pathway that is essential for symbiosis establishment. 

Lipoxygenase (LOXs) is a kind of dioxygenase without heme and iron, which plays an important role in the development and adaptation of many plants to the environment.  However, the study of strawberry LOX gene family has not been reported.  In this study, 14 LOX genes were identified from the diploid woodland strawberry genome.  The phylogenetic tree divides the FvLOX gene into two subfamilies: 9-LOX and 13-LOX.  Gene duplication event analysis showed that whole-genome duplication (WGD)/segmental duplication and dispersed duplication effectively promoted the expansion of strawberry LOX family.  QRT-PCR analysis showed that FvLOX genes were expressed in different tissues.  Expression profile analysis showed that FvLOX1 and FvLOX8 were up-regulated under low temperature stress, FvLOX3 and FvLOX7 were up-regulated under drought stress, FvLOX6 and FvLOX9 were up-regulated under salt stress, FvLOX2, FvLOX3 and FvLOX6 were up-regulated under salicylic acid (SA) treatment, FvLOX3, FvLOX11 and FvLOX14 were up-regulated under methyl jasmonate (MeJA) treatment, FvLOX4 and FvLOX14 were up-regulated under abscisic acid (ABA) treatment.  Promoter analysis showed that FvLOX genes were involved in plant growth and development and stress response.  We analyzed and identified the whole genome of strawberry FvLOX family and characterized a variety of FvLOX candidate genes involved in abiotic stress response.  This study laid a theoretical and empirical foundation for the response mechanism of strawberry to abiotic stress.

Soluble sugar content in seeds is an important quality trait of soybean.  In this study, 57 quantitative trait loci (QTLs) related to soluble sugar contents in soybean seeds were collected from databases and published papers.  After meta-overview-collinearity integrated analysis to refine QTL intervals, eight consensus QTLs were identified.  To further verify the consensus QTLs, a population of chromosome segment substitution lines (CSSLs) was analyzed.  Two lines containing fragments covering the regions of consensus QTLs and the recurrent parent were selected: one line showed high soluble sugar contents associated with a consensus QTL fragment, and the other line showed low soluble sugar contents.  Transcriptome sequencing was conducted for these two lines at the early, middle, and late stages of seed development, which identified 158, 109 and 329 differentially expressed genes, respectively.  Based on the analyses of re-sequencing data of the CSSLs and the consensus QTL region, three candidate genes (Glyma.19G146800, Glyma.19G122500, and Glyma.19G128500) were identified in the genetic fragments introduced from wild soybean.  Sequence comparisons between the two CSSL parents SN14 and ZYD00006 revealed a single nucleotide polymorphism (SNP) mutation in the coding sequence of Glyma.19G122500, causing a non-synonymous mutation in the amino acid sequence that affected the predicted protein structure.  A Kompetitive allele-specific PCR (KASP) marker was developed based on this SNP and used to evaluate the CSSLs.  These results lay the foundation for further research to identify genes related to soluble sugar contents in soybean seeds and for future soybean breeding.

Mechanisms controlling phosphorus (P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood.  In the present study, we conducted a pot experiment for four consecutive wheat–maize seasons (2016–2018) using calcareous soils with high (30.36 mg kg^–1) and low (9.78 mg kg^–1) initial Olsen-P content to evaluate the effects of conventional P fertilizer application to both wheat and maize (Pwm) along with a reduced P fertilizer application only to wheat (Pw).  The microbial community structure along with soil P availability parameters and crop yield were determined.  The results showed that the Pw treatment reduces the annual P input by 33.3% without affecting the total yield for at least two consecutive years as compared with the Pwm treatment in the high Olsen-P soil.  Soil water-soluble P concentrations in the Pw treatment were similar to those in the Pwm treatment at the 12-leaf collar stage when maize requires the most P.  Furthermore, the soil P content significantly affected soil microbial communities, especially fungal communities.  Meanwhile, the relative abundances of Proteobacteria and alkaline phosphatase (ALP) activity of Pw were significantly higher (by 11.4 and 13.3%) than those of Pwm in soil with high Olsen-P.  The microfloral contribution to yield was greater than that of soil P content in soil with high Olsen-P.  Relative abundances of Bacillus and Rhizobium were enriched in the Pw treatment compared with the Pwm treatment.  Bacillus showed a significant positive correlation with acid phosphatase (ACP) activity, and Rhizobium displayed significant positive correlations with ACP and ALP in soil with high Olsen-P, which may enhance P availability.  Our findings suggested that the application of P fertilization only to wheat is practical in high P soils to ensure optimal production in the wheat and maize double cropping system and that the soil P availability and microbial community may collaborate to maintain optimal yield in a wheat–maize double cropping system.

This study investigated the carbon (C) and nitrogen (N) gas emissions (N₂O, NH₃, CO₂ and CH₄) from solid pig manure management in China.  Gas emissions were quantified from static piles over 60 days during summer in China’s Yangtze River Basin, using Drager-Tube and static chamber-gas chromatography techniques.  High emissions of NH₃ and N₂O were observed at the early stage of storage, but high emission of CH₄ occured later during storage.  Overall, 62% of the total C in the original pile was lost; CO₂ and CH₄ emissions accounted for 57 and 0.2% of C lost respectively.  Over the same time, 41% of the total N in the original pile was lost; NH₃ and N₂O emissions accounted for 15 and 0.3% of N lost respectively.  The volatilization of NH₃ during storage in summer was 4.56 g NH₃ per kg dry weight.  The total greenhouse gas (GHG) emissions during storage accounted for 67.93 g CO₂ equivalent per kg dry weight; N₂O and CH₄ contributed to 46 and 55% of total GHG emissions respectively.  Given China’s major role in pig production, further attention should given to pig manure management to mitigate its contribution to atmospheric pollution.

The composition and quantity of amino acids influence the protein content and nutritional value of soybeans and also have an important impact upon soybean quality.  After integrating and proofreading 140 original QTLs associated with amino acid contentfrom soybase (http://www.soybase.org/), 138 QTLs were further analyzed to determine high-confidence QTL regions.  Meta-analysis was first carried out using the BioMercator ver. 2.1 software, yielding 33 consensus QTLs.  The consensus QTL confidence intervals (CIs) ranged from 0.07 to 19.85 Mb.  Next, the overview method was used to optimize the CIs, and 57 “real” QTLs were mapped.  Candidate genes in the consensus QTL regions were obtained from Phytozome and were annotated using the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Swissprot, and gene annotation databases.  Finally, 16 unpublished candidate genes controlling the content of five types of amino acids were identified with Blast.  These results laid the foundation for fine mapping of soybean amino acid-related QTLs and marker-assisted selection.

    Obtaining transgenic plants is a common method for analyzing gene function. Unfortunately, stable genetic transformation is difficult to achieve, especially for plants (e.g., soybean), which are recalcitrant to genetic transformation. Transient expression systems, such as Arabidopsis protoplast, Nicotiana leaves, and onion bulb leaves are widely used for gene functional studies. A simple method for obtaining transgenic soybean callus tissues was reported recently. We extend this system with simplified culture conditions to gene functional studies, including promoter analysis, expression and subcellular localization of the target protein, and protein-protein interaction. We also evaluate the plasticity of this system with soybean varieties, different vector constructs, and various Agrobacterium strains. The results indicated that the callus transformation system is efficient and adaptable for gene functional investigation in soybean genotype-, vector-, and Agrobacterium strain-independent modes. We demonstrated an easy set-up and practical homologous strategy for soybean gene functional studies.

    Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations and is expected to generate economic benefits via progress in pig breeding. Cytochrome P450 family 19 subfamily A polypeptide 1 (CYP19A1) gene is a key enzyme of estradiol biosynthesis that plays an important role in the establishment of gestation and maintenance of pregnancy. In this study, the sequence and structure characteristics of the porcine CYP19A1 gene was analyzed and expression patterns of CYP19A1 in different tissues of adult female pigs were detected. Fourteen single-nucleotide polymorphisms (SNPs) in the exons and introns of porcine CYP19A1 were identified and genotyped using the Sequenom MassARRAY platform, after which the allele frequency of each SNP was analyzed. The association between CYP19A1 SNPs and litter size and piglet birth weight was assessed in a crossbred pig population (n=375). The expression pattern of CYP19A1 revealed that it was highly expressed in the ovary, spleen, and uterus and lowly expressed in the other tissues. Moreover, one SNP, rs341891833, was significantly associated with piglet birth weight during the multiparity period (P<0.01). We concluded that CYP19A1 could be used as a candidate molecular marker in breeding aimed at rapid improvement of the reproductive characteristics of pigs.  

To assess levels of contamination and human health risk, we analyzed the concentrations of the heavy metals lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni) in China’s main deciduous fruits - apple, pear, peach, grape, and jujube. The concentration order of the heavy metals was Ni>Cr>Pb>Cd. In 97.5% of the samples, heavy metal concentrations were within the maximum permissible limits. Among the fruits studied, the heavy metal concentrations in jujube and peach proved to be the highest, and those in grape proved to be the lowest. Only 2.2% of the samples were polluted by Ni, only 0.4% of the samples were polluted by Pb, and no samples were polluted by Cd or Cr. Compared with the other fruits, the combined heavy metal pollution was significantly higher (P<0.05) in peach and significantly lower (P<0.05) in grape. For the combined heavy metal pollution, 96.9% of the samples were at safe level, 2.32% at warning level, 0.65% at light level, and 0.13% at moderate level. In the fruits studied, the contribution of heavy metals to the daily intake rates (DIR) followed the order of Ni>Cr>Pb>Cd. The highest DIR came from apple, while the lowest DIR came from grape. For each of the heavy metals, the total DIR from five studied fruits corresponded to no more than 1.1% of the tolerable daily intake, indicating that no significant adverse health effects are expected from the heavy metals and the fruits studied. The target hazard quotients and the total target hazard quotients demonstrated that none of the analyzed heavy metals may pose risk to consumers through the fruits studied. The highest risk was posed by apple, followed in decreasing order by peach and pear, jujube, and grape. We suggest that the main deciduous fruits (apple, pear, peach, grape, and jujube) of China’s main producing areas are safe to eat.

    To investigate the genetic diversity of an edible fungus Pleurotus ferulae, a total of 89 wild samples collected from six geographical locations in the Xinjiang Uygur Autonomous Region of China and two geographical locations in Italy, were analyzed using three DNA fragments including the translation elongation factor (EF1α), the second largest subunit of the RNA polymerase II (RPB2) and the largest subunit of the RNA polymerase II (RPB1). The results indicated relatively abundant genetic variability in the wild resources of P. ferulae. The analysis of molecular variance (AMOVA) showed that the vast majority of the genetic variation was found within geographical populations. Both the Chinese populations and the Italian populations of P. ferulae displayed a limited genetic differentiation. The degree of differentiation between the Chinese populations and the Italian populations was obviously higher than that between the populations from the same region, and moreover the genetic differentiation among all the tested populations was correlated to the geographical distance. The phylogeny analyses confirmed that samples from China and Italy belonged to another genetic group separated from Pleurotus eryngii. They were closely related to each other but were clustered according to their geographical origins, which implied the Chinese populations were highly differentiated from the Italian populations because of distance isolation, and the two populations from different regions might be still in the process of allopatric divergence.

Blue and red lights differently regulate leaf photosynthesis. Previous studies indicated that plants under blue light generally exhibit better photosynthetic characteristics than those under red light. However, the regulation mechanism of related photosynthesis characteristics remains largely unclear. Here, four light qualities treatments (300 μmol m–2 s–1) including white fluorescent light (FL), blue monochromatic light (B, 440 nm), red monochromatic light (R, 660 nm), and a combination of red and blue light (RB, R:B=8:1) were carried out to investigate their effects on the activity of photosystem II (PSII) and photosystem I (PSI), and photosynthetic electron transport capacity in the leaves of cucumber (Cucumis sativus L.) seedlings. The results showed that compared to the FL treatment, the R treatment significantly limited electron transport rate in PSII (ETRII) and in PSI (ETRI) by 79.4 and 66.3%, respectively, increased non-light induced non-photochemical quenching in PSII (ΦNO) and limitation of donor side in PSI (ΦND) and reduced most JIP-test parameters, suggesting that the R treatment induced suboptimal activity of photosystems and inhibited electron transport from PSII donor side up to PSI. However, these suppressions were effectively alleviated by blue light addition (RB). Compared with the R treatment, the RB treatment significantly increased ETRII and ETRI by 176.9 and 127.0%, respectively, promoted photosystems activity and enhanced linear electron transport by elevating electron transport from QA to PSI. The B treatment plants exhibited normal photosystems activity and photosynthetic electron transport capacity similar to that of the FL treatment. It was concluded that blue light is more essential than red light for normal photosynthesis by mediating photosystems activity and photosynthetic electron transport capacity.

Aiming at searching for plant growth promoting rhizobacteria (PGPR), a bacterium strain coded as 7016 was isolated from soybean rhizosphere and was characterized in the present study. It was identified as Burkholderia sp. based on 16S rDNA sequence analysis, as well as phenotypic and biochemical characterizations. This bacterium presented nitrogenase activity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity and phosphate solubilizing ability; inhibited the growth of Sclerotinia sclerotiorum, Gibberella zeae and Verticillium dahliae; and produced small quantities of indole acetic acid (IAA). In green house experiments, significant increases in shoot height and weight, root length and weight, and stem diameter were observed on tomato plants in 30 d after inoculation with strain 7016. Result of 16S rDNA PCR-DGGE showed that 7016 survived in the rhizosphere of tomato seedlings. In the field experiments, Burkholderia sp. 7016 enhanced the tomato yield and significantly promoted activities of soil urease, phosphatase, sucrase, and catalase. All these results demonstrated Burkholderia sp. 7016 as a valuable PGPR and a candidate of biofertilizer.

From 1985, an increasing gap has emerged between the official statistical measures of meat production and meat consumption in China, which has raised concerns from many researchers using such data. In this paper we report the results of 428 observations (survey of 107 urban and rural households×4 quarters) from 7 provinces conducted in 2010, and compare them with the official statistical data from the National Bureau of Statistics of China (NBSC). We conclude that the main reason for the discrepancy is due to the underreporting of consumption, which is due mainly to the omission of consumption away from home.

Carbon sequestration in agricultural soils is a complex process controlled by farming practices, climate and some other environment factors. Since purple soils are unique in China and used as the main cropland in Sichuan Basin of China, it is of great importance to study and understand the impacts of different fertilizer amendments on soil organic carbon (SOC) changes with time. A research was carried out to investigate the relationship between soil carbon sequestration and organic carbon input as affected by different fertilizer treatments at two long-term rice-based cropping system experiments set up in early 1980s. Each experiment consisted of six identical treatments, including (1) no fertilizer (CK), (2) nitrogen and phosphorus fertilizers (NP), (3) nitrogen, phosphorus and potassium fertilizers (NPK), (4) fresh pig manure (M), (5) nitrogen and phosphorus fertilizers plus manure (MNP), and (6) nitrogen, phosphorus and potassium fertilizers plus manure (MNPK). The results showed that annual harvestable carbon biomass was the highest in the treatment of MNPK, followed by MNP and NPK, then M and NP, and the lowest in CK. Most of fertilizer treatments resulted in a significant gain in SOC ranging from 6.48 to 29.13% compared with the CK, and raised soil carbon sequestration rate to 0.10–0.53 t ha–1 yr−1. Especially, addition of manure on the basis of mineral fertilizers was very conducive to SOC maintenance in this soil. SOC content and soil carbon sequestration rate under balanced fertilizer treatments (NPK and MNPK) in the calcareous purple soil (Suining) were higher than that in the acid purple soil (Leshan). But carbon conversion rate at Leshan was 11.00%, almost 1.5 times of that (7.80%) at Suining. Significant linear correlations between soil carbon sequestration and carbon input were observed at both sites, signifying that the purple soil was not carbon-saturated and still had considerable potential to sequestrate more carbon.

Access to security and safe food is a basic human necessity and essential for a sustainable world. To perform hi-end food safety analysis and risk assessment with state of the art technologies is of utmost importance thereof. With applications as exemplified by microfluidic immunoassay, aptasensor, direct analysis in real time, high resolution mass spectrometry, benchmark dose and chemical specific adjustment factor, this review presents frontier food safety analysis and risk assessment technologies, from which both food quality and public health will benefit undoubtedly in a foreseeable future.

Apple replant disease (ARD) causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured: yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed: hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components, (E)-2-hexenal, hexanal and 1-hexanol, significantly increased. Eight characteristic aroma components were found in the rotational cropping fruits: hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, 2-methyl- butyl butyrate, hexyl acetate and hexyl propionate. There were four characteristic ester components (hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate) and two characteristic aldehyde aroma components ((E)-2-hexenal and hexanal) in the continuous cropping fruits. Compared with the rotational cropping fruits, four characteristic ester components were declined and two characteristic aldehyde aroma components were increased. Compared with the control, replanted apple plant ground diameter, plant height increment and the total length of the current-year shoots were reduced by 27.6, 40.6 and 72.2%, respectively.