Understanding the molecular responses of tea leaves to mechanical stress is crucial for elucidating the mechanisms of post-harvest quality formation during oolong tea processing.  This study employed an integrated multi-omics strategy to characterize the changes and interactions among metabolomic (MB), transcriptomic (TX), and proteomic (PT) profiles in mechanically stressed tea leaves.  Mechanical stress initially activated damage-associated molecular patterns (DAMPs), including Ca²⁺ signaling, jasmonic acid signaling, and glutathione metabolism pathways.  These processes subsequently induced quality-related metabolic pathways (QRMPs), particularly α-linolenic acid and phenylalanine metabolism.  Up-regulated expression of LOX, ADH1, and PAR genes, together with the increased abundance of their encoded proteins, respectively promoted the accumulation of jasmine lactone, benzyl alcohol, and 2-phenylethanol.  These findings indicate that mechanical stress influences the metabolite biosynthesis in tea leaves through coordinated molecular responses.  This study provides new insights into the molecular mechanisms underlying tea leaf responses to mechanical stress and a foundation for future investigations into how early molecular events may contribute to post-harvest metabolic changes during oolong tea processing.

Porcine epidemic diarrhea virus (PEDV), an enteric coronavirus, is widely spread worldwide and causes huge economic losses.  The effective measure to control the viral infection is to develop ideal vaccines.  Here, the collagenase equivalent domain (COE) of PEDV was displayed on the surface of nanoparticles (NPs) in order to develop a newer, safer and more effective subunit vaccine against PEDV.  The monomeric COE was displayed on the mi3 protein, which self-assembles into nanoparticles composed of 60 subunits, using the SpyTag/SpyCatcher system.  The size, zeta potential, microstructure of the COE-mi3 virus-like particles (VLPs) were investigated.  The COE-mi3 VLPs that possessed good security, stability and better retention can be more efficiently taken up by antigen-presenting cells (APCs) and help promote dendritic cells (DCs) maturation.  Moreover, COE-mi3 VLPs could prominently improve specific antibody levels including neutralizing antibodies (NAbs), and serum IgG, mucosal IgA.  Moreover, COE-mi3 VLPs elicited more activation of CD4⁺ and CD8⁺ T cells and production of IFN-γ and IL-4 cytokines.  In particular, COE-mi3 VLPs is an effectual antigen-delivery platform to enhance germinal center (GC) B cell responses.  This structure-based self-assembly of NP gives great potential to be developed as a new subunit vaccines attractive platform, and may also provide new ideas for the development of other enteric coronavirus vaccines.

Avian metapneumovirus (aMPV), a paramyxovirus, causes acute respiratory diseases in turkeys and swollen head syndrome in chickens.  This study established a reverse genetics system for aMPV subtype B LN16-A strain based on T7 RNA polymerase.  Full-length cDNA of the LN16-A strain was constructed by assembling 5 cDNA fragments between the T7 promoter and hepatitis delta virus ribozyme.  Transfection of this plasmid, along with the supporting plasmids encoding the N, P, M2-1, and L proteins of LN16-A into BSR-T7/5 cells, resulted in the recovery of aMPV subtype B.  To identify an effective insertion site, the enhanced green fluorescent protein (EGFP) gene was inserted into different sites of the LN16-A genome to generate recombinant LN16-As.  The results showed that the expression levels of EGFP at the site between the G and L genes of LN16-A were significantly higher than those at the other two sites (between the leader and N genes or replacing the SH gene).  To verify the availability of the site between G and L for foreign gene expression, the VP2 gene of very virulent infectious bursal disease virus (vvIBDV) was inserted into this site, and recombinant LN16-A (rLN16A-vvVP2) was successfully rescued.  Single immunization of specific-pathogen-free chickens with rLN16A-vvVP2 induced high levels of neutralizing antibodies and provided 100% protection against the virulent aMPV subtype B and vvIBDV.  Establishing a reverse genetics system here provides an important foundation for understanding aMPV pathogenesis and developing novel vector vaccines.

Metalloid arsenic (As) is not a necessary element for plants, but its excessive accumulation is toxic to plants, and it also poses a great health risk to humans via the food chain.  Plants absorb and metabolize As through a variety of processes.  Arsenate in the form of As5+ is absorbed by phosphate transporters, but methylated As and As³⁺ enter plant tissues mainly through aquaporin channels.  Various strategies and practices have been proposed and applied to alleviate As toxicity or reduce As accumulation in plants, but an efficient and environment-friendly approach has yet to be developed.  This review comprehensively explores As sources and uptake mechanisms, as well as the interactions of phosphorus (P) and As in their uptake, transportation and influences on plant growth and physiological activities.  This comprehensive review covers the transport, metabolism, and tolerance processes that plants exhibit in response to As stress and the addition of P.  In addition, we also present recent advances in reducing As toxicity and accumulation by improving P nutrition, manipulating P transporter genes and optimizing the plant microbial community.  Finally, the future research directions and main challenges are briefly discussed.  

Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.  However, research focusing on this aspect in the production of fresh maize is limited.  Therefore, this study analyzed the effects of nitrogen application rates on the yields of 40 sweet and 44 waxy maize varieties at five sites in Zhejiang Province, China, from 2015 to 2019.  The nitrogen application rates were categorized as either relatively high (RHN, >300 kg ha^–1 for sweet maize and >320 kg ha^–1 for waxy maize) or relatively low (RLN).  An increase in nitrogen application rates significantly reduced nitrogen fertilizer partial productivity in both sweet and waxy maize (R²=0.616, P<0.01; R²=0.643, P<0.01), indicating that the optimum nitrogen application rates in this study might be the lowest values (160 kg ha^–1 for sweet maize and 180 kg ha^–1 for waxy maize).  The kernel number per ear of sweet maize had a potentially more significant impact on fresh grain yield than the 1,000-fresh kernel weight under both RLN and RHN.  In waxy maize, 1,000-kernel weight contributed more to fresh grain yield under RLN, while kernel number per ear and 1,000-kernel weight cooperatively affected the yield under RHN.  This study found that sweet maize required taller plant and ear heights, along with an optimal ear–plant height ratio, to enhance dry matter accumulation and increase source size, particularly under RLN, and to ultimately achieve a higher fresh grain yield.  In contrast, a lower ear height and ear–plant height ratio in waxy maize probably contributed more to the greater kernel number and weight under RLN, likely due to a lower ear height which can reduce the distance between sink and source, enabling more efficient photoassimilate allocation to the ear

Avian metapneumovirus (aMPV) is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys, resulting in serious economic losses.  Subtype B aMPV has recently become the dominant epidemic strain in China.  We developed an attenuated aMPV subtype B strain by serial passaging in Vero cells and evaluated its safety and efficacy as a vaccine candidate.  The safety test showed that after the 30th passage, the LN16-A strain was fully attenuated, as clinical signs of infection and histological lesions were absent after inoculation.  The LN16-A strain did not revert to a virulent strain after five serial passages in chickens.  The genomic sequence of LN16-A differed from that of the parent wild-type LN16 (wtLN16) strain and had nine amino acid mutations.  In chickens, a single immunization with LN16-A induced robust humoral and cellular immune responses, including the abundant production of neutralizing antibodies, CD4⁺ T lymphocytes, and the Th1 (IFN-γ) and Th2 (IL-4 and IL-6)

cytokines.  We also confirmed that LN16-A provided 100% protection against subtype B aMPV and significantly reduced viral shedding and turbinate inflammation.  Our findings suggest that the LN16-A strain is a promising live attenuated vaccine candidate that can prevent infection with subtype B aMPV.

The Janus kinase (JAK)–signal transducer and activator of transcription (STAT) signaling pathway plays a crucial role in innate immunity by inducing antiviral proteins in response to interferon signals. Marek’s disease virus (MDV), a member of the alpha-herpes virus family, exerts potent tumorigenic and immunosuppressive effects. Recent studies have primarily focused on the tumorigenic mechanisms of MDV, and the mechanism of immune evasion has not been fully understood. In this study, we showed that MDV reduced the production of interferon-stimulated gene (ISGs) by inhibiting the phosphorylation and nuclear translocation of STAT1. Using a dual-luciferase reporter system, we screened for viral proteins that significantly suppress interferon-stimulated response element (ISRE) promoter activity. Meq overexpression markedly reduced ISRE promoter activity and ISG expression, whereas infection with Meq-deficient MDV induced higher ISG production in vitro and in vivo than infection with wild-type MDV. Meq also inhibited the phosphorylation and nuclear translocation of STAT1. Further experiments showed that Meq interacted with JAK1 and tyrosine kinase 2 (TYK2) and thereby inhibited JAK1–STAT1 interactions. Meq degraded TYK2 via a caspase-mediated pathway. The Meq-deficient MDV mutant replicated less efficiently than the wild-type MDV, both in vitro and in vivo. Collectively, these findings demonstrate that Meq played an immunosuppressive role in MDV by attenuating the JAK–STAT signaling pathway, which facilitated escape from innate immune-surveillance mechanisms.

Plastic film mulching (PFM) increases crop yields in semi-arid regions by reducing water losses and increasing soil temperature, while crop production in these areas also serves as a significant source of ammonia (NH₃) emissions.  The effects of PFM on NH₃ emissions are nearly unknow because of interactions between larger N mineralization at higher temperature and film cover preventing NH₃ diffusion.  Therefore, our objectives were to (1) evaluate the effects of PFM on NH₃ emissions under field conditions, and (2) identify the maize yield and NH₃ emissions under climate change and atmospheric N deposition using the DeNitrification-DeComposition (DNDC) model.  The experimental treatments included four treatments: (1) no plastic film mulching without N fertilization (control), (2) plastic film mulching without N fertilization (PFM), (3) N fertilization without plastic film mulching (N), and (4) plastic film mulching with N fertilization (PFM+N).  The PFM increased maize yields by 211% and yield stability across the years when combined with N fertilization.  PFM reduced NH₃ emissions by 35% through three mechanisms: i) high water content under PFM saturates soil pores, hindering NH₃ gas movement to atmosphere, ii) the hot and wet conditions under PFM accelerates nitrification rate, thus increasing pH buffering capacity during urea hydrolysis, and iii) the physical barrier created by PFM reduced NH₃ exchange between soil and air.  Daily NH₃ emissions increased with soil temperature, NH₄⁺ content, and pH, but declined with soil moisture under N fertilization.  The NH₃ emissions under PFM+N increased with NH₄⁺ content.  The parameterised DNDC model simulated very well the yield and daily NH₃ emissions. PFM+N increased yield and reduced NH₃ emissions under the shared socioeconomic pathway (SSP) scenario and the N deposition.  Yield under PFM+N increased with increasing N deposition, while NH₃ emissions under N deposition increased under the high radiative forcing scenario (SSP5-8.5).  Concluding, PFM increase yields and mitigate NH₃ emissions, and it also has the potential to achieve similar benefits under future conditions.

Triticeae represents one of the most significant sources of cereal crops in Poaceae, including wheat, barley, and rye. Global annual production reaches 900 million tons, constituting 30% of total grain production. The utilization of wild relatives is crucial for enhancing crop resilience. Sea barley (Hordeum marinum Huds), a wild relative species of wheat and barley, demonstrates exceptional salt/waterlogging tolerance and other valuable traits. Moreover, it exhibits partial cross-compatibility with common wheat. Sea barley has emerged as an essential donor of elite genes for crop breeding, with potential applications both as a de novo domesticated crop and as forage cultivated in saline-alkali soils and waterlogged areas. This review synthesizes current knowledge regarding sea barley, emphasizing its origin, evolution, genome characteristics, genetic transformation, mechanisms of stress tolerance, fungal resistance, and cross-compatibility with wheat. Additionally, we identify key knowledge gaps and future research directions to enhance its utilization for crop breeding and novel crop development, aiming to transform sea barley from an underutilized wild grass into a genetic resource for climate-smart agriculture.

Photosynthesis serves as the primary source of nutrients synthesized in higher plants, and enhancing photosynthetic efficiency can significantly improve crop yield and fruit quality. Leaf color mutants, which are ideal materials for studying chloroplast development and photosynthesis mechanisms, have been extensively investigated in field crops. However, the study on their application in watermelon remains limited. In this study, we identified a yellow-green phenotype mutant, PKH352, from an EMS mutagenesis watermelon mutant library. The chlorophyll content and maximal photochemical efficiency in PKH352 was significantly reduced. Genetic analysis showed that the mutated trait was controlled by a single nuclear gene, which named as Clygp (Citrullus lanatus yellow-green plant). Through MutMap and linkage analysis in an F₂ population of 440 plants, we identified a single nucleotide polymorphism (SNP) mutation in ClG42_04g0106300, which encoded a signal recognition particle 54 kDa protein, as the causal variant for the yellow-green phenotype. Further validation using a CRISPR/Cas9-mediated system confirmed that knockout of ClG42_04g0106300 results in the yellow-green phenotype in watermelon. In addition, comparative transcriptomic analysis revealed that the ClG42_04g0106300 mutations greatly affected the expression of key genes associated with chloroplast development and photosynthesis, providing strong evidence that it plays a critical role in these biological pathways. Taken together, these findings provide insights into the molecular mechanisms underlying chloroplast development and photosynthetic efficiency, offering a theoretical basis for breeding watermelon varieties with high photosynthetic efficiency.

Poor soil structure and low soil fertility are the main factors limiting crop yield in Vertisol. Although deep tillage and organic fertilization are potential amelioration strategies, their interactive effects remain insufficiently explored. The high salinity in commercial organic fertilizer may negatively affect soil structure and crop growth. The objectives were to: (1) evaluate whether the combination of deep tillage and commercial organic fertilization could more effectively enhance soil structure and fertility; (2) quantify the primary factors and their contributions to crop yield. A 9-year experiment was conducted under a wheat–maize rotation system in a Vertisol, involving two tillage practices—rotary tillage (RT) and deep ploughing (DP)—and three fertilization treatments: mineral fertilizer (NPK), 100% organic fertilizer (OM), and a combination of mineral with 50% organic fertilizer (NPKOM). Soil physicochemical properties were determined, and soil physical quality was quantified by the least limiting water range (LLWR). Our results showed that, compared to NPK, OM and NPKOM treatment decreased soil bulk density (r_b), increased saturated water conductivity (K_s), enlarged LLWR, and enhanced SOC and soil nutrient contents in the 10-30cm layer. When combined with DP, soils became more porous and nutrient-rich, particularly in deeper soil layers. However, long-term commercial organic fertilization introduced substantial amounts of salt ions (Na⁺, K⁺, Cl^-, SO₄^2-), leading to significantly increased soil EC_1:1 and decreased aggregate stability (MWD). The EC in the soil pore solution even exceeded the crop tolerance thresholds during the growth season. Among several soil indicators, EC_1:1 is represented as the primary factor limiting wheat yield. While maize yield was promoted by the increased TN due to the greater nutrient requirement and salt leaching into deeper layers under higher precipitation. The intensified reduction in wheat yield with the prolonged fertilization duration further confirmed the increased negative effect of salt stress under organic fertilization. By incorporating surface salts into deeper soil layers, DP mitigated soil salt stress and reduced yield losses than RT. Our results demonstrated that the long-term application of commercial organic fertilizers led to salt accumulation that adversely affects crop yields in Vertisols. Although deep tillage mitigated the salt stress, it cannot fully offset the yield reduction caused by salt accumulation. Further studies across a wider variety of soil types, organic fertilizer sources, and fertilization gradients are needed to elucidate the wide-ranging effects of commercial organic fertilization.

Overapplication of nitrogen (N) is an important limiting factor in sustainable agricultural development. Breeding N-efficient genotypes is an effective approach to reduce crop N input, increase N-efficiency, and improve crop productive. However, the molecular mechanisms underlying low-N adaptations in peanut (Arachis hypogaea L.) roots are unknown. Herein, we compared root adaptation mechanisms to low-N stress between the N-efficient genotype JH15 (JH) and the N-inefficient genotype HY20 (HY), focusing on N metabolism and antioxidant capacity. Under N deficiency, JH exhibited a more developed root architecture, higher antioxidant activity, and higher N-metabolic enzyme levels under N deficiency. The expression of both high- and low-affinity nitrate transporter proteins (NRT2.5, NRT1.6), and the chloride channel protein CLC was upregulated in JH, with higher expression of genes encoding glutamine synthetase and asparagine synthase. However, only the low-affinity N transporters (NPF5.2, NPF7.3) were upregulated in HY. Flavonoid and isoflavonoid biosynthesis were the main metabolic pathways underlying the differences between the two genotypes under low-N treatment. The results of weighted gene co-expression network analysis and correlation network analysis revealed that differential expression of the key genes encoding caffeoyl-CoA O-methyltransferase, chalcone synthase, 2'-hydroxyisoflavone reductase, and shikimate hydroxycinnamoyl-CoA transferase affected key metabolites levels (epicatechin, kaempferol, calycosin, and biochanin A). We also found that WRKY40 and MYB30, MYB4, and bHLH35 may regulate flavonoids accumulation as positive and negative regulators, respectively. In summary, enhanced N uptake and assimilation and flavonoid accumulation in JH enhanced N metabolism and antioxidant capacity, improving N-efficiency.

The root system is an important organ for cotton to absorb water and nutrients. Different cotton varieties respond differently to drought stress. Therefore, this study firstly conducted an indoor experiment using 384 cotton varieties as materials, to screen long and short root varieties. Subsequently, a field experiment was performed to analyze the differences in drought responses between these two types of varieties. And then through genome-wide association analysis (GWAS), screened for candidate genes. The research results showed that, based on the total root length (TRL) as the main indicator in the indoor experiment, five long-root type varieties PD2164, B557, CCRI No.30, Super Jijiao Dezi Mian and Dunn HS120, and five short-root type varieties Bole 34, Henan No.79, CCRI No.50, V83-013 and Ari3696 were selected. The results of the drought stress experiment showed that under drought conditions, the average TRL increase of long-root type varieties (5.49%) was smaller than that of short-root type varieties (15.45%, P<0.05); the yields of long-root type varieties and short-root type varieties decreased by 19-35% and 10-37% respectively. It is notable that under drought conditions, the TRL increase of short-root type variety HN79 was the highest, at 69%, and the yield decrease was the lowest, at 10%, demonstrating higher drought resistance. We also identified SNPs related to the primary root traits in the At02 region 101.2-101.6 Mb through GWAS, and determined that GhAIL6 is a root development-related gene. This study identified ten cotton varieties exhibiting extreme long-root and short-root phenotypes. Further analysis showed that some short-root varieties exhibited greater increases in total root length and smaller reductions in yield under drought stress, indicating stronger drought resistance. Additionally, the study elucidated the pivotal role of GhAIL6 in promoting root growth during the cotton seedling stage.