UBL-UBA protein functions as a shuttle factor in the 26S ubiquitin degradation pathway, playing a critical role in plant growth and development, and responding to various biotic and abiotic stresses.  Although RAD23, a type of UBL-UBA protein, has been extensively studied in several plants, there is currently no comprehensive analysis available for kiwifruit (Actinidia chinensis).  In this study, we identified six AcRAD23 genes in kiwifruit and further analyzed their phylogenetic relationships, gene structure, conserved motif composition and cis-acting element in the promoter.  Subcellular localization experiments revealed that all AcRAD23 were localized in the nucleus and the cell membranes.  Quantitative real-time PCR (qRT-PCR) analysis demonstrated differential expression patterns of these AcRAD23 genes across different tissues and under various stress conditions (drought, waterlogging, salt stress, etc.), with AcRAD23D1 showing the highest responsiveness to abiotic stress.  Additionally, we investigated the biological function of AcRAD23D1 using VIGS-mediated gene silencing methods under drought stress conditions.  Suppression of AcRAD23D1 expression resulted in reduced relative water content (RWC) but increased malondialdehyde (MDA) content and relative electrolyte leakage (REL) levels in D1-VIGS lines compared to control lines.  Furthermore, D1-VIGS lines exhibited a higher accumulation of reactive oxygen species (ROS) along with decreased superoxide dismutase (SOD) and peroxidase (POD) enzyme activities.  These findings suggest that AcRAD23D1 may play a positive role in regulating kiwifruit’s response to drought stress.  Our results provide new insights into the potential involvement of AcRAD23 under abiotic stress conditions while offering a theoretical foundation for understanding the molecular mechanisms underlying kiwifruit’s adaptation to stresses. 

Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems, but how these root-associated fungi (RAF) differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.  Here, we constructed an 11-year experiment involving fungicide application (with or without) nested within four levels of experimental nitrogen (N) addition treatments in an alpine pasture, and the RAF communities, root traits, tissue nutrients, and shoot biomass of two dominant forage species (Carex capillifolia and Elymus nutans) were analyzed.  The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.  Fungicide, but not N application, dramatically reduced the RAF richness of all functional guilds in both plant species, and fungicide also simplified the co-occurrence network of the RAF for C. capillifolia.  The RAF community correlated strongly with root traits, whereas their relationships became weakened or even vanished at the level of the individual plant species.  The importance of RAF to plant nutrients and productivity varied between plant species, with significant contributions in C. capillifolia but not in E. nutans.  This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures, and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.

Streptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen that clinically causes severe swine and human infections (such as meningitis, endocarditis, and septicemia).  In order to cause widespread diseases in different organs, S. suis 2 must colonize the host, break the blood barrier, and cause exaggerated inflammation.  In the last few years, most studies have focused on a single virulence factor and its influences on the host.  Membrane vesicles (MVs) can be actively secreted into the extracellular environment contributing to bacteria-host interactions.  Gram-negative bacteria-derived outer membrane vesicles (OMVs) were recently shown to activate host Caspase-11-mediated non-canonical inflammasome pathway via deliverance of OMV-bound lipopolysaccharide (LPS), causing host cell pyroptosis.  However, little is known about the effect of the MVs from S. suis 2 (Gram-positive bacteria without LPS) on cell pyroptosis.  Thus, we investigated the molecular mechanism by which S. suis 2 MVs participate in endothelial cell pyroptosis.  In this study, we used proteomics, electron scanning microscopy, fluorescence microscope, Western blotting, and bioassays, to investigate the MVs secreted by S. suis 2.  First, we demonstrated that S. suis 2 secreted MVs with an average diameter of 72.04 nm, and 200 proteins in MVs were identified.  Then, we showed that MVs were transported to cells via mainly dynamin-dependent endocytosis.  The S. suis 2 MVs activated NLRP3/Caspase-1/GSDMD canonical inflammasome signaling pathway, resulting in cell pyroptosis, but it did not activate the Caspase-4/-5 pathway.  More importantly, endothelial cells produce large amounts of reactive oxygen species (ROS) and lost their mitochondrial membrane potential under induction by S. suis 2 MVs.  The results in this study suggest for the first time that MVs from S. suis 2 were internalized by endothelial cells via mainly dynamin-dependent endocytosis and might promote NLRP3/Caspase-1/GSDMD pathway by mitochondrial damage, which produced mtDNA and ROS  under induction, leading to the pyroptosis of endothelial cells.

The application of a male-sterile line is an ideal approach for hybrid seed production in non-heading Chinese cabbage (Brassica rapa ssp. chinensis).  However, the molecular mechanisms underlying male sterility in B. rapa are still largely unclear.  We previously obtained the natural male sterile line WS24-3 of non-heading Chinese cabbage and located the male sterile locus, Bra2Ms, on the A2 chromosome.  Cytological observations revealed that the male sterility of WS24-3 resulted from disruption of the meiosis process during pollen formation.  Fine mapping of Bra2Ms delimited the locus within a physical distance of about 129 kb on the A2 chromosome of B. rapa.  The Bra039753 gene encodes a plant homeodomain (PHD)-finger protein and is considered a potential candidate gene for Bra2Ms.  Bra039753 was significantly downregulated in sterile line WS24-3 compared to the fertile line at the meiotic anther stage.  Sequence analysis of Bra039753 identified a 369 bp fragment insertion in the first exon in male sterile plants, which led to an amino acid insertion in the Bra039753 protein.  In addition, the 369 bp fragment insertion was found to cosegregate with the male sterility trait.  This study identified a novel locus related to male sterility in non-heading Chinese cabbage, and the molecular marker obtained in this study will be beneficial for the marker-assisted selection of excellent sterile lines in non-heading Chinese cabbage and other Brassica crops.

Hydraulic theory predicts a positive coupling between leaf hydraulic conductance (K_leaf) and stomatal conductance (g_s); however, this theory has not been fully supported by observations, and the underlying mechanisms remain unclear.  Currently, subdividing K_leaf into leaf hydraulic conductance inside xylem (K_x) and outside xylem (K_ox) offers a new perspective for elucidating the regulatory mechanism of K_leaf on g_s.  Optimal planting density can enhance water use efficiency (WUE) by optimizing g_s; however, the changes in leaf hydraulic properties during this process and its regulation of g_s and WUE remain unclear.  We examined the relationships between K_x and K_ox with g_s, photosynthetic rate (A_N), and WUE, and investigated the structural basis determining K_ox in cotton under eight planting densities of 12, 18, 24, 36, 48, 60, 72, and 84 plant m^-².  The results showed that as the increase of planting density, K_leaf and A_N remained consistent while K_ox and g_s decreased significantly.  K_ox was significantly influenced by leaf thickness and the volume fraction of inter-cellular air space.  K_leaf and K_x showed no correlation with A_N or g_s, but K_ox exhibited a significant positive correlation with g_s.  Furthermore, K_ox is significantly negatively correlated with WUE.  These findings suggest that K_ox modulates g_s to reduce water loss while maintaining A_N, thereby enhancing WUE in cotton under various planting densities.

Excellent nitrogen (N) management techniques can improve crop yields while mitigating reactive N (Nr) losses. The synergistic effects of applying paired N management techniques have important implications for designing excellent N management strategies, but the interaction effects remain poorly known. Here, a meta-analysis was conducted to quantify the effects of optimized N management techniques (optimized N application rate, optimized topdressing, and applying enhanced-efficiency fertilizers) on wheat yield, N use efficiency (NUE), and Nr losses, as well as the interactive effects of paired N management techniques (combining an optimized N rate with topdressing or enhanced-efficiency fertilizers). The results demonstrated that an optimized N fertilizer rate reduced Nr losses by 28–31% while the wheat yield declined by 2%; however, the wheat yield increased by 2% when the reduction of N fertilizer was less than 20%. The adoption of topdressing and enhanced-efficiency fertilizers significantly increased wheat yields by 4–8% and NUE by 8–14%, while reducing Nr losses by 28–40%, and high topdressing frequency and nitrification inhibitors showed stronger positive effects on wheat yield. Paired N management techniques increased wheat yields by 3–4% and NUE by 37–38%, with additive or synergistic effects; and they also reduced Nr losses by 5–66% but showed an antagonistic effect. Such non-additive interactions amplified the positive effects on wheat production, but the benefits in terms of environmental risk reduction were weakened. Overall, this study highlights the importance of synergistic effects in innovative N management to address the trade-off between crop yield and Nr losses.

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.

Tick-borne encephalitis (TBE) is an important zoonotic viral disease transmitted by ticks. In recent decades, global climate change has increased human exposure to ticks, and mortality rates have gradually risen. Effective vaccines are essential for controlling TBE as specific antiviral treatment is unavailable. Vaccine candidates based on virus-like particles (VLPs) have previously been demonstrated to be efficient in eliciting excellent immune responses against influenza virus and SARS-CoV-2. Here, we constructed TBE virus (TBEV) VLPs containing the envelope and membrane proteins derived from the Far Eastern TBEV strain (WH2012) using an insect cell-baculovirus expression system. Induction of immune responses was investigated in mice following intramuscular injection with the TBEV VLPs vaccine candidates formulated of Poly(I:C) & Montanide ISA 201VG combination adjuvants. Mice produced memory T-cells and serum-specific IgG antibodies that averaged up to 1:10^4.6 and remained at 1:10⁴ (mean) for 24 weeks after three immunizations. TBEV VLPs vaccine was able to provide long-term antibody protection against TBEV, making it a promising subunit vaccine candidate for this disease.

In order to explore the molecular mechanisms underlying the contribution of autophagy to pepper’s heat tolerance, in previous study, we identified the zinc-finger protein B-BOX 9/CONSTANS-LIKE 13 (CaBBX9/CaCOL13) as an interaction partner of Autophagy regulated protein (ATG) CaATG8c, one of the core components in autophagy. However, the involvements of CaBBX9 in both autophagy and heat tolerance remain unclear. In this study, we further confirmed the interaction between CaBBX9 with CaATG8c, and defined the interaction regions of CaBBX9 are CONSTANS, CONSTANS-Like and TOC1 (CCT) domain and the fragment region. The expression of CaBBX9 can be induced by heat treatment. CaBBX9 is co-localized with CaATG8c in the nucleus and exhibits a transcriptional activity. When the expression of CaBBX9 is silenced, the heat-tolerance of pepper is enhanced, shown by the decrement of MDA content, H₂O₂, dead cells, and relative electrolyte leakage, and the increment of chlorophyll content and expression level of heat stress related genes. Overexpression of CaBBX9 in tomatoes displays the opposite effects. Taken together, our study demonstrates that CaBBX9 negatively regulates the heat-tolerance of peppers by exacerbating oxidative damage and inhibiting the expression of heat related genes. Our findings provide a new clue for guiding crop breeding for tolerance to adverse environment.