IntroductionPeanut production is being increasingly threatened by water stress with the context of global climate change. Film mulching have been reported to alleviate the adverse impact of drought on peanut. Lower phosphorus use efficiency is another key factor limiting peanut yield. Application of iron-modified and phosphorus-loaded biochar (BIP) has been validated to enhance phosphorus utilization efficiency in crops. However, whether combined effect of film mulching and BIP could increase water use efficiency and enhance peanut production through regulating soil properties and root morphologies needs further investigation.MethodsA two-year (2021-2022) pot experiment using a split-plot design was conducted to investigate the effects of phosphorus fertilizer substitution using BIP on soil properties, root morphology, pod yield, and water use of peanut under film mulching. The main plots were two mulching methods, including no mulching (M0) and film mulching (M1). The subplots were four combined applications of phosphorus fertilizer with BIP, including conventional phosphorus fertilizer rates (PCR) without BIP, P1C0; 3/4 PCR with 7.5 t ha-1 BIP, P2C1; 3/4 PCR with 15 t ha-1 BIP, P2C2; 2/3 PCR with 7.5 t ha-1 BIP, P3C1; 2/3 PCR with 15 t ha-1 BIP, P3C2.Results and discussionThe results indicated that regardless of biochar amendments, compared with M0, M1 increased soil organic matter and root morphology of peanut at different growth stages in both years. In addition, M1 increased peanut yield and water use efficiency (WUE) by 18.8% and 51.6%, respectively, but decreased water consumption by 25.0%, compared to M0 (two-year average). Irrespective of film mulching, P2C1 increased length, surface area, and volume of peanut root at seedling by 16.7%, 17.7%, and 18.6%, at flowering by 6.6%, 19.9%, and 29.5%, at pod setting by 22.9%, 33.8%, and 37.3%, and at pod filling by 48.3%, 9.5%, and 38.2%, respectively (two-year average), increased soil pH and organic matter content during peanut growing season, and increased soil CEC at harvest. In general, the M1P2C1 treatment obtained the optimal root morphology, soil chemical properties, WUE, and peanut yield, which increased peanut yield by 33.2% compared to M0P1C0. In conclusion, the combination of film mulching with 7.5 t ha-1 BIP (M1P2C1) effectively improved soil chemical properties, enhanced root morphology of peanut, and ultimately increased peanut yield and WUE.

The species diversity of AMF is influenced by the cultivar of the host plant. For this study, six species of poplar (Populus spp.) were selected from the poplar germplasm conservation experimental forest in Tongzhou, Beijing, China. The aim of the study was to compare the chemical characteristics of the poplar stand soils, including total carbon, total nitrogen, total phosphorus, and available phosphorus. The composition of the AMF community was also analyzed using high-throughput sequencing techniques. Significant differences in soil nutrient content (total phosphorus, available phosphorus, carbon/nitrogen, carbon/phosphorus) were found between different species of Populus spp. (p < 0.05), although the total carbon, total nitrogen, and nitrogen/phosphorus of the soil did not differ significantly (p > 0.05). Notably, the Simpson index and Pielou index of the AMF community exhibited the most significant differences among the various poplar cultivars, with the highest mean values for P. × euramericana cl. ‘J6’ (0.98 and 0.77, respectively). Furthermore, significant correlations were observed between the relative abundance of AMF communities at each taxonomic level and soil nutrient content. At the generic level, the relative abundance of Glomus has the highest correlation with C/N and C/P (r = −0.79). Overall, the findings of this study highlight the impact of poplar species on the composition and structure of the soil AMF community, which is closely related to soil nutrient content. These results contribute to our understanding of the plant–AMF–soil interaction mechanisms and provide a solid basis for future research in this field.

Cross-species transmission of viruses from wildlife animal reservoirs, such as bats, poses a threat to human and domestic animal health. Previous studies have shown that domestic animals have important roles as intermediate hosts, enabling the transmission of genetically diverse coronaviruses from natural hosts to humans. Here, we report the identification and characterization of a novel canine coronavirus (VuCCoV), which caused an epidemic of acute diarrhea in Vulpes (foxes) in Shenyang, China. The epidemic started on November 8, 2019, and caused more than 39,600 deaths by January 1, 2022. Full-length viral genomic sequences were obtained from 15 foxes with diarrhea at the early stage of this outbreak. The VuCCoV genome shared more than 90% nucleotide identity with canine coronavirus (CCoV) for three of the four structural genes, with the S gene showing a larger amount of divergence. In addition, 67% (10/15) of the VuCCoV genomes contained an open reading frame (ORF3) gene, which was previously only detected in CCoV-I genomes. Notably, VuCCoV had only two to three amino acid differences at the partial RNA-dependent RNA polymerase (RdRp) level to bat CoV, suggesting a close genetic relationship. Therefore, these novel VuCCoV genomes represent a previously unsampled lineage of CCoVs. We also show that the VuCCoV spike protein binds to canine and fox aminopeptidase N (APN), which may allow this protein to serve as an entry receptor. In addition, cell lines were identified that are sensitive to VuCCoV using a pseudovirus system. These data highlight the importance of identifying the diversity and distribution of coronaviruses in domestic animals, which could mitigate future outbreaks that could threaten livestock, public health, and economic growth.

IntroductionThe above-ground parts of terrestrial plants are collectively known as the phyllosphere. The surface of the leaf blade is a unique and extensive habitat for microbial communities. Phyllosphere bacteria are the second most closely associated microbial group with plants after fungi and viruses, and are the most abundant, occupying a dominant position in the phyllosphere microbial community. Host species are a major factor influencing the community diversity and structure of phyllosphere microorganisms. MethodsIn this study, six Populus spp. were selected for study under the same site conditions and their phyllosphere bacterial community DNA fragments were paired-end sequenced using 16S ribosomal RNA (rRNA) gene amplicon sequencing. Based on the distribution of the amplicon sequence variants (ASVs), we assessed the alpha-diversity level of each sample and further measured the differences in species abundance composition among the samples, and predicted the metabolic function of the community based on the gene sequencing results. ResultsThe results revealed that different Populus spp. under the same stand conditions resulted in different phyllosphere bacterial communities. The bacterial community structure was mainly affected by the carbon and soluble sugar content of the leaves, and the leaf nitrogen, phosphorus and carbon/nitrogen were the main factors affecting the relative abundance of phyllosphere bacteria. DiscussionPrevious studies have shown that a large proportion of the variation in the composition of phyllosphere microbial communities was explained by the hosts themselves. In contrast, leaf-borne nutrients were an available resource for bacteria living on the leaf surface, thus influencing the community structure of phyllosphere bacteria. These were similar to the conclusions obtained in this study. This study provides theoretical support for the study of the composition and structure of phyllosphere bacterial communities in woody plants and the factors influencing them.

As an ecological index for plants, the diversity and structure of phyllosphere microbial communities play a crucial role in maintaining ecosystem stability and balance; they can affect plant biogeography and ecosystem function by influencing host fitness and function. The phyllosphere microbial communities reflect the immigration, survival, and growth of microbial colonists, which are influenced by various environmental factors and leaves' physical and chemical properties. This study investigated the structure and diversity of phyllosphere fungal communities in three different Populus spp., namely-P. × euramaricana (BF3), P. nigra (N46), and P. alba × P. glandulosa (84K). Leaves' chemical properties were also analyzed to identify the dominant factors affecting the phyllosphere fungal communities. N46 exhibited the highest contents of total nitrogen (Nt), total phosphorus (Pt), soluble sugar, and starch. Additionally, there were significant variations in the abundance, diversity, and composition of phyllosphere fungal communities among the three species: N46 had the highest Chao1 index and observed_species, while 84K had the highest Pielou_e index and Simpson index. Ascomycota and Basidiomycota are the dominant fungal communities at the phylum level. Results from typical correlation analyses indicate that the chemical properties of leaves, especially total phosphorus (Pt), total nitrogen (Nt), and starch content, significantly impact the structure and diversity of the phyllosphere microbial community. However, it is worth noting that even under the same stand conditions, plants from different species have distinct leaf characteristics, proving that the identity of the host species is the critical factor affecting the structure of the phyllosphere fungal community.

Flooding has become one of the major abiotic stresses that seriously affects plant growth and development owing to changes in the global precipitation pattern. Mulberry (Morus alba L.) is a desirable tree spePhysocarpus amurensis Maxim andcies with high ecological and economic benefits. To reveal the response and adaptive mechanisms of the photosynthetic functions of mulberry leaves to flooding stress, chlorophyll synthesis, photosynthetic electron transfer and the Calvin cycle were investigated by physiological studies combined with an analysis of the transcriptome. Flooding stress inhibited the synthesis of chlorophyll (Chl) and decreased its content in mulberry leaves. The sensitivity of Chl a to flooding stress was higher than that of Chl b owing to the changes of CHLG (LOC21385082) and CAO (LOC21408165) that encode genes during chlorophyll synthesis. The levels of expression of Chl b reductase NYC (LOC112094996) and NYC (LOC21385774), which are involved in Chl b degradation, were upregulated on the fifteenth day of flooding, which accelerated the transformation of Chl b to Chl a, and upregulated the expression of PPH (LOC21385040) and PAO (LOC21395013). This accelerated the degradation of chlorophyll. Flooding stress significantly inhibited the photosynthetic function of mulberry leaves. A Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of differentially expressed genes under different days of flooding stress indicated significant enrichment in Photosynthesis-antenna proteins (map00196), Photosynthesis (map00195) and Carbon fixation in photosynthetic organisms (map00710). On the fifth day of flooding, 7 and 5 genes that encode antenna proteins were identified on LHCII and LHCI, respectively. They were significantly downregulated, and the degree of downregulation increased as the trees were flooded longer. Therefore, the power of the leaves to capture solar energy and transfer this energy to the reaction center was reduced. The chlorophyll fluorescence parameters and related changes in the expression of genes in the transcriptome indicated that the PSII and PSI of mulberry leaves were damaged, and their activities decreased under flooding stress. On the fifth day of flooding, electron transfer on the PSII acceptor side of mulberry leaves was blocked, and the oxygen-evolving complex (OEC) on the donor side was damaged. On the tenth day of flooding, the thylakoid membranes of mulberry leaves were damaged. Five of the six coding genes that mapped to the OEC were significantly downregulated. Simultaneously, other coding genes located at the PSII reaction center and those located at the PSI reaction center, including Cytb6/f, PC, Fd, FNR and ATP, were also significantly downregulated. In addition, the gas exchange parameters (Pn, Gs, Tr, and Ci) of the leaves decreased after 10 days of flooding stress primarily owing to the stomatal factor. However, on the fifteenth day of flooding, the value for the intracellular concentration of CO2 was significantly higher than that on the tenth day of flooding. In addition, the differentially expressed genes identified in the Calvin cycle were significantly downregulated, suggesting that in addition to stomatal factors, non-stomatal factors were also important factors that mediated the decrease in the photosynthetic capacity of mulberry leaves. In conclusion, the inhibition of growth of mulberry plants caused by flooding stress was primarily related to the inhibition of chlorophyll synthesis, antenna proteins, photosynthetic electron transfer and the Calvin cycle. The results of this study provide a theoretical basis for the response and mechanism of adaptation of the photosynthetic function of mulberry to flooding stress.

Pinus sylvestris var. mongolica is widely planted in China as a windbreak and sand fixation tree. To improve the current situation of large-scale declines of forested areas planted as P. sylvestris var. mongolica monocultures, we investigated the biological and microbial effects of stand establishment using mixed tree species. The interactions during the mixed decomposition of the litter and leaves of different tree species are an important indicator in determining the relationships among species. In this experiment, a method of simulating the mixed decomposition of P. sylvestris var. mongolica and Morus alba litter under P. sylvestris var. mongolica forest was used to determine the total C, total N, and total P contents in the leaf litter, and the microbial structures were determined by using Illumina MiSeq high-throughput sequencing. It was found that with samples with different proportions of P. sylvestris var. mongolica and M. alba litters, the decomposition rate of P. sylvestris var. mongolica × M. alba litter was significantly higher than that of the pure P. sylvestris var. mongolica forest, and the microbial community and composition diversity of litter in a pure P. sylvestris var. mongolica forest could be significantly improved. The possibility of using M. alba as a mixed tree species to address the declines of pure P. sylvestris var. mongolica forest was verified to provide guidance for pure P. sylvestris var. mongolica forests by introducing tree species with coordinated interspecific relationships and creating a mixed forest.

Purpose To report the first complete fox coronavirus (CoV) genome sequence obtained through genome-wide amplifications and to understand the adaptive evolution of fox CoV. Methods Anal swab samples were collected from 35 foxes to detect the presence of CoV and obtain the virus sequence. Phylogenetic analysis was conducted using MrBayes. The possibility of recombination within these sequences was assessed using GARD. Analysis of the levels of selection pressure experienced by these sequences was assessed using methods on both the PAML and Data Monkey platforms. Results Of the 35 samples, two were positive, and complete genome sequences for the viruses were obtained. Phylogenetic analysis, using Bayesian methods, of these sequences, together with other CoV sequences, revealed that the fox CoV sequences clustered with canine coronavirus (CCoV) sequences, with sequences from other carnivores more distantly related. In contrast to the feline, ferret and mink CoV sequences that clustered into species-specific clades, the fox CoV fell within the CCoV clade. Minimal evidence for recombination was found among the sequences. A total of 7, 3, 14, and 2 positively selected sites were identified in the M, N, S, and 7B genes, respectively, with 99, 111, and 581 negatively selected sites identified in M, N, and S genes, respectively. Conclusion The complete genome sequence of fox CoV has been obtained for the first time. The results suggest that the genome sequence of fox CoV may have experienced adaptive evolution in the genes replication, entry, and virulence. The number of sites in each gene that experienced negative selection is far greater than the number that underwent positive selection, suggesting that most of the sequence is highly conserved and important for viral survive. However, positive selection at a few sites likely aided these viruses to adapt to new environments.

Background Dogs are domesticated wolves. Change of living environment, such as diet and veterinary care may affect the gut bacterial flora of dogs. The aim of this study was to assess the gut bacterial diversity and function in dogs compared with captive wolves. We surveyed the gut bacterial diversity of 27 domestic dogs, which were fed commercial dog food, and 31 wolves, which were fed uncooked meat, by 16S rRNA sequencing. In addition, we collected fecal samples from 5 dogs and 5 wolves for shotgun metagenomic sequencing to explore changes in the functions of their gut microbiome. Results Differences in the abundance of core bacterial genera were observed between dogs and wolves. Together with shotgun metagenomics, the gut microbiome of dogs was found to be enriched in bacteria resistant to clinical drugs ( P < 0.001), while wolves were enriched in bacteria resistant to antibiotics used in livestock ( P < 0.001). In addition, a higher abundance of putative α-amylase genes ( P < 0.05; P < 0.01) was observed in the dog samples. Conclusions Living environment of dogs and domestic wolves has led to increased numbers of bacteria with antibiotic resistance genes, with exposure to antibiotics through direct and indirect methods. In addition, the living environment of dogs has allowed the adaptation of their microbiota to a starch-rich diet. These observations align with a domestic lifestyle for domestic dogs and captive wolves, which might have consequences for public health.