Stigma color is a critical agronomic trait in watermelon that plays an important role in pollination.  However, there are few reports on the regulation of stigma color in watermelon.  In this study, a genetic analysis of the F₂ population derived from ZXG1553 (P₁, with orange stigma) and W1-17 (P₂, with yellow stigma) indicated that stigma color is a quantitative trait and the orange stigma is recessive compared with the yellow stigma.  Bulk segregant analysis sequencing (BSA-seq) revealed a 3.75 Mb segment on chromosome 6 that is related to stigma color.  Also, a major stable effective QTL Clqsc6.1 (QTL stigma color) was detected in two years between cleaved amplified polymorphic sequencing (CAPS) markers Chr06_8338913 and Chr06_9344593 spanning a ~1.01 Mb interval that harbors 51 annotated genes.  Cla97C06G117020 (annotated as zinc finger protein CONSTANS-LIKE 4) was identified as the best candidate gene for the stigma color trait through RNA-seq, quantitative real-time PCR (qRT-PCR), and gene structure alignment analysis among the natural watermelon panel.  The expression level of Cla97C06G117020 in the orange stigma accession was lower than in the yellow stigma accessions with a significant difference.  A nonsynonymous SNP site of the Cla97C06G117020 coding region that causes amino acid variation was related to the stigma color variation among nine watermelon accessions according to their re-sequencing data.  Stigma color formation is often related to carotenoids, and we also found that the expression trend of ClCHYB (annotated as β-carotene hydroxylase) in the carotenoid metabolic pathway was consistent with Cla97C06G117020, and it was expressed in low amounts in the orange stigma accession.  These data indicated that Cla97C06G117020 and ClCHYB may interact to form the stigma color.  This study provides a theoretical basis for gene fine mapping and mechanisms for the regulation of stigma color in watermelon. 

Quality and yield are the primary concerns in kiwifruit breeding, but research on the genetic mechanisms of fruit size, shape, and ascorbic acid (ASA) content is currently very limited, which restricts the development of kiwifruit molecular breeding.  In this study, we obtained a total of 8.88 million highly reliable single nucleotide polymorphism (SNP) markers from 140 individuals from the natural hybrid offspring of Actinidia eriantha cv. ‘White’ using whole genome resequencing technology.  A genome-wide association study was conducted on eight key agronomic traits, including single fruit weight, fruit shape, ASA content, and the number of inflorescences per branch.  A total of 59 genetic loci containing potential functional genes were located, and candidate genes related to single fruit weight, fruit length, ASA content, number of inflorescences per branch and other traits were identified within the candidate interval, such as AeWUSCHEL, AeCDK1 (cell cycle dependent kinase), AeAO1 (ascorbic oxidase) and AeCO1 (CONSTANS-like 4).  After constructing an RNAi vector for AeAO1 and injecting it into the fruit of cv. ‘Midao 31’ to interfere with the expression of the AeAO1 gene, the results showed that the activity of ascorbic oxidase in the fruit of ‘Midao 31’ significantly decreased, while the content of ASA significantly increased.  This study provides valuable insights into the genetic basis of variation in A. eriantha fruit traits, which may benefit molecular marker-assisted breeding efforts.

Global demand for farm animals and their meat products i.e., pork, chicken and other livestock meat, is steadily incresing. With the ongoing life science research and the rapid development of biotechnology, it is a great opportunity to develop advanced molecular breeding markers to efficiently improve animal meat production traits.  Hippo is an important study subject because of its crucial role in the regulation of organ size.  In recent years, with the increase of research on Hippo signaling pathway, the integrative application of multi-omics technologies such as genomics, transcriptomics, proteomics, and metabolomics can help promote the in-depth involvement of Hippo signaling pathway in skeletal muscle development research.  The Hippo signaling pathway plays a key role in many biological events, including cell division, cell migration, cell proliferation, cell differentiation, cell apoptosis, as well as cell adhesion, cell polarity, homeostasis, maintenance of the face of mechanical overload, etc.  Its influence on the development of skeletal muscle has important research value for enhancing the efficiency of animal husbandry production.  In this study, we traced the origin of the Hippo pathway, comprehensively sorted out all the functional factors found in the pathway, deeply analyzed the molecular mechanism of its function, and classified it from a novel perspective based on its main functional domain and mode of action.  Our aim is to systematically explore its regulatory role throughout skeletal muscle development.  We specifically focus on the Hippo signaling pathway in embryonic stem cell development, muscle satellite cell fate determination, myogenesis, skeletal muscle meat production and organ size regulation, muscle hypertrophy and atrophy, muscle fiber formation and its transformation between different types, and cardiomyocytes.  The roles in proliferation and regeneration are methodically summarized and analyzed comprehensively.  The summary and prospect of the Hippo signaling pathway within this article will provide ideas for further improving meat production and muscle deposition and developing new molecular breeding technologies for livestock and poultry, which will be helpful for the development of animal molecular breeding.

Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice.  This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.  The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble.  At the same time, a ¹³C stable isotope in-situ detection technology was used to fertilize the pot experiment.   The results showed significant interactions among varieties, water management, nitrogen application and stubble status.  Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes.  This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice.  Furthermore, the partitioning of ¹³C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice.  This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time.  We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental, coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.

Salinity is one of the most significant risks to crop production and food security as it harms plant physiology and biochemistry.  The salt stress during the rice emergence stages severely hampers the seed germination and seedling growth of direct-seeded rice.  Recently, nanoparticles (NPs) have been reported to be effectively involved in many plant physiological processes, particularly under abiotic stresses.  To our knowledge, no comparative studies have been performed to study the efficiency of conventional, chemical, and seed nanopriming for better plant stress tolerance.  Therefore, we conducted growth chamber and field experiments with different salinity levels (0, 1.5, and 3‰), two rice varieties (CY1000 and LLY506), and different priming techniques such as hydropriming, chemical priming (ascorbic acid, salicylic acid, and γ-aminobutyric acid), and nanopriming (zinc oxide nanoparticles).  Salt stress inhibited rice seed germination, germination index, vigor index, and seedling growth.  Also, salt stress increased the over accumulation of reactive oxygen species (H₂O₂ and O₂^-·) and malondialdehyde (MDA) contents.  Furthermore, salt-stressed seedlings accumulated higher sodium (Na⁺) ions and significantly lower potassium (K⁺) ions.  Moreover, the findings of our study demonstrated that, among the different priming techniques, seed nanopriming with zinc oxide nanoparticles (NanoZnO) significantly contributed to rice salt tolerance.  ZnO nanopriming improved rice seed germination and seedling growth in the pot and field experiments under salt stress.  The possible mechanism behind ZnO nanopriming improved rice salt tolerance included higher contents of α-amylase, soluble sugar, and soluble protein and higher activities of antioxidant enzymes to sustain better seed germination and seedling growth.  Moreover, another mechanism of ZnO nanopriming induced rice salt tolerance was associated with better maintenance of K⁺ ions content.  Our research concluded that NanoZnO could promote plant salt tolerance and be adopted as a practical nanopriming technique, promoting global crop production in salt-affected agricultural lands.

Certain outsourcing services for agricultural management in China, such as pest control in grain production, have experienced prolonged sluggishness, contrasting with the relatively high level of outsourcing services observed in harvesting, land preparation, and sowing.  This study examines the feasibility of implementing whole-step outsourcing in grain production by conducting a case study of rice and maize production in Jiangsu, Jilin, and Sichuan provinces in China.  The provision of outsourcing services hinges on two essential conditions: technological advancements fostering specialized production and economies of scale, coupled with a market size sufficient to realize the aforementioned potential economies of scale.  The results showed that outsourcing pest control or harvesting services had varying economies of scale.  The outsourcing services in pest control were less common than in harvesting services, and their marginal growth space of the economies of scale with technological change was also smaller.  Determined by the operational characteristics of pest control itself, the market scale of its professional services is small.  Therefore, achieving the whole-step outsourcing of grain production necessitates not only technological innovation but also effective policy interventions to overcome the constraints of market scale.  Such interventions include (1) optimizing crop layouts between planning regions and reducing land fragmentation and (2) supplying timely and effective inter-regional agricultural information for service providers aided by information technology.

Cyperus difformis L. is a troublesome weed in paddy fields and has attracted attention due to its resistance to acetohydroxyacid synthase (AHAS) inhibitors.  It was found that the amino acid mutation in AHAS was the primary cause for the resistance of Cyperus difformis.  However, the effect of different mutations on AHAS function is not clear in Cyperus difformis.  To confirm the effect of mutations on AHAS function, six biotypes were collected, including Pro197Arg, Pro197Ser, Pro197Leu, Asp376Glu, Trp574Leu and wild type, from Hunan, Anhui, Jiangxi and Jiangsu provinces, China and the function of AHAS was characterized.  The AHAS in vitro inhibition assay results indicated that the mutations decreased the sensitivity of AHAS to pyrazosulfuron-ethyl, in which the I₅₀ (the half maximal inhibitory concentration) of wild type AHAS was 0.04 μmol L^–1 and Asp376Glu, Pro197Leu, Pro197Arg, Pro197Ser and Trp574Leu mutations were 3.98, 11.50, 40.38, 38.19 and 311.43 μmol L^–1, respectively.  In the determination of enzyme kinetics parameters, the Km and the maximum reaction velocity (Vmax) of the wild type were 5.18 mmol L^–1 and 0.12 nmol mg^–1 min^–1, respectively, and the Km values of AHAS with Asp376Glu, Trp574Leu, Pro197Leu and Pro197Ser mutations were 0.38–0.93 times of the wild type.  The Km value of the Pro197Arg mutation was 1.14 times of the wild type, and the Vmax values of the five mutations were 1.17–3.33-fold compared to the wild type.  It was found that the mutations increased the affinity of AHAS to the substrate, except for the Pro197Arg mutation.  At a concentration of 0.0032–100 mmol L^–1 branched-chain amino acids (BCAAs), the sensitivity of the other four mutant AHAS biotypes to feedback inhibition decreased, except for the Pro197Arg mutation.  This study elucidated the effect of different mutations on AHAS function in Cyperus difformis and provided ideas for further study of resistance development.

 

Heavy metal contamination has been regarded as an environmental variable that affects the efficiency of pest biological control, but the parasitic fitness of parasitoids under heavy metal stress is poorly understood.  Herein, the effect of Cd exposure through the host pupa of Hyphantria cunea on the parasitic fitness of Chouioia cunea was investigated, and the mechanism by which Cd exposure affects the interaction between H. cunea and C. cunea from the perspective of innate immunity in host insect and the oxidative status in the parasitoid offspring was explored.  Our results indicated that Cd can be transferred from the H. cunea pupae to the parasitoid offspring, and the transfer coefficient reflected biological amplification.  There were no significant differences in the rates of parasitism success and offspring emergence between the untreated and Cd-treated groups.  However, after parasitizing Cd-accumulated pupae, the parasitic fitness of offspring wasps (e.g., the number, individual size and life span) decreased significantly.  Under Cd exposure, the cellular and humoral immunity of H. cunea pupae decreased significantly.  Compared with the untreated group, the H₂O₂ content of parasitoid offspring in the Cd-treated group was significantly increased.  Cd exposure significantly inhibited superoxide dismutase activity in parasitoid offspring, but the contents of ascorbic acid and glutathione were significantly increased by Cd stress.  Taken together, these results indicate that Cd exposure reduces the cyclic utilization efficiency of C. cunea on H. cunea pupae.  The oxidative status of parasitoid offspring triggered by Cd exposure could be responsible for the reduced parasitic fitness of C. cunea on Cd-accumulated H. cunea pupae.

In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including: malic acid (Mal), oxalic acid (Oxa), citric acid (Cit), lactic acid (Lac), succinic acid (Suc), fumaric acid (Fum), total organic acids (ToA, the sum of the six organic acids tested), titratable acid (TiA), acidity value (AcV), and pH value.  For most of the cultivars studied (85.8%), the order of the organic acid contents in apples was Mal>Oxa>Cit>Lac>Suc>Fum.  Mal was the dominant organic acid, on average, accounting for 94.5% of ToA.  Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%.  There were significant linear relationships between Mal and two indices (ToA and AcV) as well as between ToA and AcV.  There were significant logarithmic relationships between pH value and four indices: Mal, TiA, ToA, and AcV.  All the equations had very high fitting accuracy and can be used to accurately predict related indices.  According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution.  Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established.  The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal.  The grading standards of these five indices can be used to evaluate the sour flavor of apple.  This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.

Crop root system plays an important role in the water cycle of the soil-plant-atmosphere continuum. In this study, combined isotope techniques, root length density and root cell activity analysis were used to investigate the root water uptake mechanisms of winter wheat (Triticum aestivum L.) under different irrigation depths in the North China Plain. Both direct inference approach and multisource linear mixing model were applied to estimate the distribution of water uptake with depth in six growing stages. Results showed that winter wheat under land surface irrigation treatment (T_s) mainly absorbed water from 10–20 cm soil layers in the wintering and green stages (66.9 and 72.0%, respectively); 0–20 cm (57.0%) in the jointing stage; 0–40 (15.3%) and 80–180 cm (58.1%) in the heading stage; 60–80 (13.2%) and 180–220 cm (35.5%) in the filling stage; and 0–40 (46.8%) and 80–100 cm (31.0%) in the ripening stage. Winter wheat under whole soil layers irrigation treatment (Tw) absorbed more water from deep soil layer than T_s in heading, filling and ripening stages. Moreover, root cell activity and root length density of winter wheat under T_w were significantly greater than that of T_s in the three stages. We concluded that distribution of water uptake with depth was affected by the availability of water sources, the root length density and root cell activity. Implementation of the whole soil layers irrigation method can affect root system distribution and thereby increase water use from deeper soil and enhance water use efficiency.

The adsorption of Cu(II) from aqueous solution onto humic acid (HA) which was isolated from cattle manure (CHA), peat (PHA), and leaf litter (LHA) as a function of contact time, pH, ion strength, and initial concentration was studied using the batch method. X-ray absorption spectroscopy (XAS) was used to examine the coordination environment of the Cu(II) adsorbed by HA at a molecular level. Moreover, the chemical compositions of the isolated HA were characterized by elemental analysis and solid-state 13C nuclear magnetic resonance spectroscopy (NMR). The kinetic data showed that the adsorption equilibrium can be achieved within 8 h. The adsorption kinetics followed the pseudo-second-order equation. The adsorption isotherms could be well fitted by the Langmuir model, and the maximum adsorption capacities of Cu(II) on CHA, PHA, and LHA were 229.4, 210.4, and 197.7 mg g–1, respectively. The adsorption of Cu(II) on HA increased with the increase in pH from 2 to 7, and maintained a high level at pH>7. The adsorption of Cu(II) was also strongly influenced by the low ionic strength of 0.01 to 0.2 mol L–1 NaNO3, but was weakly influenced by high ionic strength of 0.4 to 1 mol L–1 NaNO3. The Cu(II) adsorption on HA may be mainly attributed to ion exchange and surface complexation. XAS results revealed that the binding site and oxidation state of Cu adsorbed on HA surface did not change at the initial Cu(II) concentrations of 15 to 40 mg L–1. For all the Cu(II) adsorption samples, each Cu atom was surrounded by 4 O/N atoms at a bond distance of 1.95 Å in the first coordination shell. The presence of the higher Cu coordination shells proved that Cu(II) was adsorbed via an inner-sphere covalent bond onto the HA surface. Among the three HA samples, the adsorption capacity and affinity of CHA for Cu(II) was the greatest, followed by that of PHA and LHA. All the three HA samples exhibited similar types of elemental and functional groups, but different contents of elemental and functional groups. CHA contained larger proportions of methoxyl C, phenolic C and carbonyl C, and smaller proportions of alkyl C and carbohydrate C than PHA and LHA. The structural differences of the three HA samples are responsible for their distinct adsorption capacity and affinity toward Cu(II). These results are important to achieve better understanding of the behavior of Cu(II) in soil and water bodies in the presence of organic materials.

Soil water is strongly affected by land use/cover in the Loess Plateau in China. Water stored in thick loessal soils is one of the most important resources regulating vegetation growth. However, soil water in the deep loess profile, which is critical for maintaining the function of the “soil water pool” is rarely studied because deep profile soil samples are difficult to collect. In this study, four experimental plots were established in 2005 to represent different farming systems on the Changwu Tableland: fallow land, fertilized cropland, unfertilized cropland, and continuous alfalfa. The soil water content in the 15-m-deep loess profiles was monitored continuously from 2007 to 2012 with the neutron probe technique. The results showed that temporal variations in soil water profiles differed among the four farming systems. Under fallow land, the soil water content increased gradually over time, first in the surface layers and later in the deep soil layers. In contrast, the soil water content decreased gradually under continuous alfalfa. The distributions of soil water in deep soil layers under both fertilized and unfertilized cropland were relatively stable over time. Thus farming system significantly affected soil water content. Seven years after the start of the experiment, the soil water contents in the 15-m-deep profiles averaged 23.4% under fallow land, 20.3% under fertilized cropland, 21.6% under unfertilized cropland, and 16.0% under continuous alfalfa. Compared to measurements at the start of the experiment, both fallow land and unfertilized cropland increased soil water storage in the 15-m loess profiles. In contrast, continuous alfalfa reduced soil water storage. Fertilized cropland has no significant effect on soil water storage. These results suggest that deep soil water can be replenished under the fallow and unfertilized farming systems. Dry soil layers (i.e., those which have soil water content less than the stable field water capacity) in the subsoil of the Changwu Tableland region can be classified as either temporary dry soil layers or persistent dry soil layers. Temporary dry soil layers, which typically form under annual crops, often disappear during wet years. Persistent dry soil layers generally develop under perennial vegetation. Even after removing the vegetation, persistent dry soil layers remain for several decades. This study provides information useful for the conservation and utilization of soil water resources in the Loess Tableland.

indica and japonica are the two most important subspecies of Asian cultivated rice. Identifying mechanisms responsible for population differentiation in these subspecies is important for indica-japonica hybridization breeding. In this study, subspecies and economic trait differentiation patterns were analyzed using morphological and molecular (InDel and Intron Length Polymorphism) data in F2 and F3 populations derived from indica-japonica hybridization. Populations were grown in Liaoning and Guangdong provinces, China, with F3 populations generated from F2 populations using bulk harvesting (BM) and single-seed descent methods (SSD). Segregation distortion was detected in F3-BM populations, but not in F3- SSD or in F2 populations. Superior performance was observed with respect to economic traits in Liaoning compared with that in Guangdong and 1 000-grain weight (KW), seed setting rate (SSR) and grain yield per plant (GYP) were significantly correlated with indica and japonica subspecies types. Analysis of molecular and morphological data demonstrated that the environment is the main factor giving rise to population differentiation in indica-japonica hybridization. In addition, we also found that KW, SSR and GYP are related to subspecies characteristics and kinship, which is possibly a significant factor resulting in economic trait differentiation and determining environmental adaptability. Our study has provided new insights into the process of population differentiation in these subspecies to inform indica-japonica hybridization breeding.

A set of 240 introgression lines derived from the advanced backcross population of a cross between a japonica cultivar,Xiushui 09, and an indica breeding line, IR2061, was developed to dissect QTLs affecting cold tolerance (CT) at seedlingstage and heat tolerance (HT) at anthesis. Survival rate of seedlings (SRS) and spikelet fertility (SF), the index traits of CTand HT, showed significant differences between the two parents under stresses. A total of four QTLs (qSRS1, qSRS7,qSRS11a and qSRS11b) for CT were identified on chromosomes 1, 7, 11, and the Xiushui 09 alleles increased SRS at all lociexcept qSRS7. Four QTLs for SF were identified on chromosomes 4, 5, 6, and 11. These QTLs could be classified into twomajor types based on their behaviors under normal and stress conditions. The first was QTL expressed only under normalcondition; and the second QTL was apparently stress induced and only expressed under stress. Among them, two QTLs(qSF4 and qSF6) which reduced the trait difference between heat stress and normal conditions must have contributed toHT because of their obvious contribution to trait stability, and the IR2061 allele at the qSF6 and the Xiushui 09 allele at the qSF4improved HT, respectively. No similar QTL was found between CT at seedling stage and HT at anthesis. Therefore, it ispossible to breed a new variety with CT and HT by pyramiding the favorable CT- and HT-improved alleles at above locifrom Xiushui 09 and IR2061, respectively, through marker-assisted selection (MAS).

Streptococcus suis serotype 2 (SS2) is an emerging zoonotic pathogen that causes meningitis in humans and pigs. It not only brings huge economic losses to the pig industry but also seriously threatens public health security. However, the mechanisms by which SS2 enters the brain and induces meningitis is not fully understood. Here, we investigated the role and mechanism of the SS2 collagenase-like protease (Clp) in promoting the passage of the bacterium across the blood-brain barrier (BBB). We found that SS2 Clp enhanced virulence and tissue colonization, and promoted the destruction of the BBB in mice. Compared with wild-type SS2, the ability of a Δclp mutant to cross human brain microvascular endothelial (hCMEC/D3) cell monolayers

decreased, whereas the addition of recombinant protein rClp increased permeability. rClp also significantly promoted the adhesion of SS2 to hCMEC/D3, inhibited the expression of intercellular tight junction proteins ZO-1, Occludin, and Claudin-5 independent of its enzyme activity, and induced hCMEC/D3 apoptosis through the cell receptor ligand apoptosis and mitochondrial apoptosis pathways partly dependent on its enzyme activity, resulting in BBB destruction and increased permeability. Moreover, Clp increased macrophage (F4/80+), monocytes (F4/80-Ly6C+), and neutrophils (Ly6G+) infiltration into the brain after SS2 infection. Thus, SS2 Clp is required for the passage of the bacterium across the BBB, and the results, provide a theoretical basis for better prevention and treatment of SS2-induced meningitis.

Long-term excessive nitrogen (N) application does not increase or even decreases grain yield and N use efficiency (NUE) of maize, in which the roles of root morphological and physiological characteristics are not clear.  The goal of this study was to explain the mechanism underlying no increment in grain yield under excessive N application from the perspective of root morpho-physiological characteristics.  A 10-year long-term N fertilizer trial was conducted in Jilin Province, Northeast China, growing maize at three N fertilizer levels (zero N, N0; recommended N, N2; and high N level, N4) in 2019, 2020 and 2021.  Two widely planted maize genotypes: ‘Xianyu 335’ (XY335) and ‘Zhengdan 958’ (ZD958) were used.  Grain yield, N content, root morphology and other physiological characteristics were analyzed to further evaluate the relationships between N uptake, N utilization, plant growth, and root systems under different N treatments.  Compared with N0, root biomass, post-silking N uptake and grain yield were significantly improved with increased N input, whereas no significant differences were observed between recommended N and high N.  High N application increased root length and root surface area, but decreased root activity (measured by TTC (2,3,5-triphenyltetrazolium chloride) method), nitrate reductase activity and root activity absorbing area regardless of genotypes.  Root length and root to shoot ratio negatively contributed to N uptake (by -1.2% and -24.6%), while root surface area, root activity, nitrate reductase activity and root activity absorbing area were positively contributed to N uptake.  The interaction effect between cultivar and N application was significant on NUE.  XY335 obtained the highest NUE (11.6%) and N recovery efficiency (18.4%) through higher root surface area (23.6%), root activity (12.5%), nitrate reductase activity (8.3%) and root activity absorbing area (6.9%) compared with other treatments.  Overall, recommended N application promoted Post N uptake, NUE and grain yield by root surface area and root activity, nitrate reductase activity and root activity absorbing area, while high N application did not increase or even decreased NUE by reducing root surface area, root activity, nitrate reductase activity and root activity absorbing area.  Our case study successfully revealed that root surface area, root activity, nitrate reductase activity and root activity absorbing area were the limiting factors of NUE increase under high N application.

Germplasm resources are essential for the sustainable development of biodiversity and husbandry of local chickens, as well as for the breeding and industry of superior quality chickens. Unfortunately, many local and indigenous chicken breeds are at risk of declining numbers, emphasizing the need to conserve breed resources for endangered chickens. Primordial germ cells (PGCs) are crucial for preserving germplasm resources by inheriting genetic information from parents to offspring and ensuring stability of genetic material between germlines. In this study, PGCs were isolated from chicken embryos' gonads and cultured in FAcs medium without feeder cells. Over a period of approximately 40 days, the cells proliferated to a number of up to 10⁶, establishing various cell lines. Particularly, 18 PGC lines were created from Rugao Yellow Chicken and Shouguang Chicken, with an efficiency ranging from 39.1% to 45%. Furthermore, PGCs that had been cultured for 40 passages exhibited typical PGC characteristics, such as glycogen staining reaction, and expression of pluripotency and reproductive markers. These results confirm that PGCs maintain stem cell properties even after long-term in vitro culture. Additionally, PGCs cryopreserved for up to 120 days remained viable, maintained typical PGC morphologies, and possessed stable cell proliferation ability. Through intravascular injection into chicken embryos, green fluorescent protein (GFP)-PGCs were found in the recipient embryos' gonads and could develop into gametes to produce offspring, indicating that even after extended culture, PGCs retain their migratory and lineage-transmitting capabilities. This research offers valuable insights into the in vitro cultivation and preservation of PGCs of Chinese indigenous chickens. The findings of this study can be applied in transgenic chicken production and the preservation of genetic resources of indigenous chicken breeds.

Sulforaphane (SFN), a naturally occurring isothiocyanate found in cruciferous vegetables, is known for its anti-inflammatory and antioxidant effects in the body. However, whether its dietary addition impact porcine liver health, and if so, by which mechanims remains unclear. In this study, the diet of growing pigs was supplemented with 1 g kg^-1 SFN and was found to improve growth performance and hepatocellular proliferation. Further analyses revealed that SFN decreased hepatic and serum malondialdehyde levels, while increasing glutathione peroxidase (GSH-PX) activity in the liver. Transcriptomic and proteomic studies demonstrated that SFN down-regulated multiple pathways, including oxidative phosphorylation, inflammatory responses, IL-6-JAK-STAT3 signaling, and TNFα signaling via NFκB. Meanwhile, it upregulated NRF2/GPX4/HO-1 expression and reduced IL-6 and TNFα expression. Mechanistic studies identified potential NR1D1 and NRF2 binding elements in the promoters of the GPX4 and HO-1 genes in the liver. Furthermore, Metabolomic profiling revealed a decline in serum β-hydroxybutyrate levels after the administration of SFN, while further analysis confirmed that SFN enhanced a type of epigenetic modification in the liver, lysine β-hydroxybutyrylation (Kbhb).  These results highlight SFN protective roles against liver inflammation and oxidative damage and propose a novel mechanism involving NRF2 and NR1D1 synergy, with SFN’s promotion of hepatic Kbhb necessitating further exploration.

Soil compaction has become a seriously limitation for further increasing grain yield of maize (Zea mays L.) in the North China Plain (NCP).  However, considerable variability exists among maize hybrids in their grain yield response to soil compaction.  To understand the physiological processes relate to the variation of responses to various soil compactions among maize hybrids, a two-year field experiment was conducted with 17 maize hybrids and three soil compaction treatments (NC, no compaction, SBD, soil bulk density=1.0-1.3 g cm^-3; MC, moderate compaction, SBD=1.4-1.5 g cm^-3, and HC, heavy compaction, SBD>1.6 g cm^-3) to examine the root and shoot morphological traits, dry matter accumulation, and grain yield.  Compared to NC, MC and HC significantly decreased maize yield by 0.9-26.7% and 5.9-41.1% across hybrids and years, respectively.  High compaction tolerance (H) had greater grain yield than hybrids of middle compaction tolerance (M) and low compaction tolerance (L), particularly under HC.  Yield benefits obtained from H hybrid were enhanced due to better root and shoot growth under HC condition.  Greater root length, root surface area, and root weight, as well as root activity, absorption capacity, and antioxidant capacity for H hybrid were found under HC condition, and then maintained increased leaf area index and dry matter accumulation.  Moreover, the increases of root growth indices for H hybrid were greater than that of shoot growth, particularly under HC condition, leading to an increased root/shoot ratio.  We conclude that soil compaction impacts maize root and shoot growth differently depending on genotype, and root growth advantages of H hybrid were more obviously than shoot growth, which enhanced the yield benefits from H hybrid under heavy compaction condition.

CRISPR/Cas9-based gene editing research has advanced greatly and shows broad potential for practical application in life sciences, but the Cas9 system is often constrained by the requirement of a protospacer adjacent motif (PAM) at the target site. While xCas9, a variant derived from Streptococcus pyogenes Cas9 (SpCas9), can recognize a broader range of PAMs, its application in non-model insects is lacking. In this study, we explored xCas9 activity in gene editing by selecting corazonin (Crz) and the target sites with various PAMs in Locusta migratoria, a destructive insect pest worldwide. We found that xCas9 could cleave the target site with AG PAM while SpCas9 could not, although xCas9 appeared to have lower activity than SpCas9 at the canonical NGG PAMs. The heritable homozygous Crz^-/- locust strain was generated by the application of xCas9. The Crz^-/- strain showed an albino body color, with significantly downregulated expression of several body color-related genes including Pale, Vermilion, Cinnabar, White and β-carotene-binding protein. In addition, Crz^-/- mutants exhibited significantly reduced expression of Chitin synthase 1, along with a markedly lower chitin content as well as compact and rigid cuticles. Furthermore, Crz^-/- mutants displayed impaired performance under low-temperature stress, including prolonged lifespan, reduced body weight and smaller body size. Our results suggest that xCas9 is effective for insect genome editing, and Crz plays essential roles in insect body color, cuticle development and adaptation to low-temperature stress. The findings of this study extend the application of xCas9 in non-model insects and provide new insights into our understanding of the regulation of insect cuticle development and environmental adaptation.

Tartary buckwheat (Fagopyrum tataricum), an under-utilized pseudocereal, has important nutritional and pharmaceutical properties and is resistant to drought and nutrient deficiency.  However, this environmentally friendly crop is sensitive to salt stress that can result in water loss, stomatal closure, affect photosynthesis and metabolism, and reduce yield and quality of Tartary buckwheat.  Thus, it is important to understand the mechanism of salt stress tolerance in buckwheat. In this study, we identified a locus including 35 candidate genes on chromosome 2 that is significantly associated with salt tolerance of Tartary buckwheat by genome-wide association analysis (GWAS).  Transcriptome analysis revealed that the serine/threonine-protein kinase Aurora-3 (FtAUR3) family gene was up-regulated in response to salt stress.  The deletion of a single nucleotide in the FtAUR3 promoter leads to increased FtAUR3 expression and enhanced salt tolerance in Tartary buckwheat.  Overexpression of FtAUR3 in buckwheat hairy roots leads to the accumulation of flavonoids, including rutin and cinnamic acid, as well as the induction of the expression of flavonoid biosynthesis genes, such as PAL, C4H, F3H and F3’H, under salt stress.  In addition, it was shown that over-expression of FtAUR3 in Arabidopsis thaliana induced the expression of salt-resistant genes (SOS1, AVP1, etc.) and enhanced salt tolerance compared to wild type plants.  Furthermore, under salt stress, FtAUR3 can significantly enhances the levels of reactive oxygen species pathway components, including superoxide dismutase, catalase, and peroxidase, thereby improving plant salt tolerance.  Thus, we demonstrated that FtAUR3 interacts with the critical enzyme FtGAPB in the ROS pathway, suggesting a potential mechanism through which FtAUR3 contributes to ROS signaling.  Taken together, these results demonstrated that FtAUR3 may play a critical positive role in Tartary buckwheat resistance against salt stress.