Climate warming and soil microplastic pollution seriously threaten agricultural production safety. Clarifying the ecological response characteristics and physiological molecular mechanisms of rice (Oryza sativa) under these dual environmental stresses is the core key to coping with agricultural ecological adversity. This study used greenhouse pot experiments to simulate a 1.5 ℃ warming treatment and set polyethylene microplastic (PE-MPs) pollution gradients of 0%, 1%, 2%, 5%, and 10% (w/w). The study systematically evaluated the apparent growth parameters, photosynthetic pigment content, and oxidative stress indicators of rice under the combined stresses of warming and soil microplastics. The results showed that the single PE-MPs treatment significantly promoted the accumulation of the basal stem and aboveground and belowground biomass of rice (P<0.05), had no significant effect on the chlorophyll content, and the oxidative damage in the roots was significantly higher than that in the leaves (P<0.05). The warming treatment changed the morphology of rice, leading to a significant increase in plant height, root length and basal stem (P<0.05). Although it had no significant effect on the aboveground biomass, it significantly increased the belowground biomass. At the same time, it caused a significant increase in the chlorophyll content, as well as the contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in the leaves (P<0.05). The combined treatment of both factors had a more pronounced inhibition on and photosynthetic content of root length and stem diameter compared to the single treatment. For the roots, the combined treatment only significantly increased SOD at 1% and 2% concentrations and alleviated the warming-induced increase in catalase (CAT), peroxidase (POD), and MDA. In summary, the effects of PE-MPs and warming on rice were not entirely synergistic, and PE-MPs caused mechanical damage to the rice roots. This study revealed the traits and complex interactive effects of global warming and PE-MPs on rice growth and development, providing experimental evidence for the risk assessment of agricultural ecosystems under climate change and theoretical support to develop pollution prevention and control strategies in agriculture.

Winter Brassica rapa is an important oilseed crop in China, with strong adaptability, excellent agronomic traits and high production efficiency. Low-temperature adversity ranks among the most critical abiotic constraints throughout its developmental stages. To understand the molecular mechanism of cold resistance of winter B. rapa, in this study, two-dimensional electrophoresis was employed to identify differentially expressed proteins in the shoot apical meristem of winter B. rapa 'Longyou 7' exposed to low-temperature stress. Furthermore, bioinformatics approaches were utilized to perform functional annotation and pathway enrichment analysis on these differentially expressed proteins. The results showed that low-temperature stress induced 24 significantly differentially expressed proteins, among which 8 were up-regulated, 10 were down-regulated, and 6 were induced expression proteins. Go annotation results revealed that the majority of differentially expressed proteins participated in the response to low-temperature stress, antioxidant defense, energy metabolism, and cell structure maintenance processes. Analysis based on the KEGG database uncovered the pivotal roles played by differentially expressed proteins in carbon metabolism, photosynthetic carbon fixation, as well as multiple amino acid biosynthetic pathways. S-adenosylmethionine synthase 2 (SAMS2) gene was associated with low-temperature response and had the highest expression level at 12 h of low-temperature treatment. The encoded protein was a stable hydrophilic protein with a conserved domain, and its promoter region contained cis-acting elements such as low-temperature response. BrSAMS2 might participate in the low-temperature response by regulating methyl donors and ethylene synthesis. This study provides new candidate genes and protein targets for revealing the molecular mechanism of cold tolerance in winter rapeseed.

Acid phosphatase (ACP) is a key enzyme in plant phosphate metabolism, and elucidation of its gene expression regulation mechanism is of great theoretical value for improving plant phosphorus utilization efficiency. In this study, qPCR was used to detect the tissue expression pattern of SlACP (Gene ID: Solyc06g062380.3) in tomato (Solanum lycopersicum). The promoter of SlACP gene was cloned and fused to the GUS reporter gene in the p1300GN expression vector, and transgenic Arabidopsis thaliana was obtained via Agrobacterium tumefaciens-mediated transformation. The expression pattern of SlACP in transgenic plants were detected by GUS histochemical staining. Additionally, bioinformatics analysis was used to predict the cis-acting elements of the promoter. The qPCR results showed that SlACP was predominantly expressed in tomato roots. GUS histochemical staining showed that SlACP was highly expressed in Arabidopsis thaliana roots. Bioinformatics analysis revealed that promoter of SlACP contained multiple root-specific expression elements. The combination of GUS histochemical staining and qPCR results indicated that the promoter of the SlACP gene was a root-specific promoter. The findings above provide important theoretical basis and genetic resources for developing molecular breeding of phosphorus-efficient crops using this promoter.

Solanum nigrum (Solanaceae) is an important plant for both food and medicine. The F-box family gene UNUSUAL FLORAL ORGANS (UFO) plays a critical role in the regulation of the inflorescence structure establishment and floral organ development. Previous study showed that overexpression of a truncated SnUFO2 gene (lacking 23 amino acids at the C-terminus) leads to abnormal floral organ development. To further investigate the function of SnUFO2 in flower development, this study conducted spatiotemporal expression analysis of SnUFO2, creating overexpression transgenic lines, morphological observations, and detecting the expression of class B floral organ identity genes. Spatiotemporal expression analysis showed that SnUFO2 was specifically expressed in the apical meristem at the flowering stage. qPCR analysis revealed that SnUFO2 was expressed in the sepals, petals, stamens, and pistils of early flower buds, and its expression in sepals and petals was significantly higher than leaves, stamens and carpels (P<0.05). Morphological observations showed that transgenic S. nigrum plants overexpressing SnUFO2 exhibited dwarfism, early flowering, conversion of cyme inflorescences into single flowers, petaloid sepals, and carpels transformed into stamen-carpel fused organs. Furthermore, qPCR analysis revealed that the expression levels of the B-class floral organ identity genes SnGLOBOSA (SnGLO), SnPISTILLATA (SnPI28), SnDEFICIENS (SnDEF), and SnDEFICIENS 64 (SnDEF64) were significantly upregulated in the transgenic flowers (P<0.05), implying that SnUFO2 played a conserved role in inflorescence architecture and floral organ development by positively regulating expression of the B-class floral organ identity genes. This study provides a theoretical reference and research ideas for flower and fruit thinning using biotechnology approaches.

Lactate dehydrogenase (LDH) is not only a key enzyme for energy supply in plants under hypoxic conditions but also participates in various abiotic stress responses. In this study, members of the LDH gene family were first screened and identified from the genome of Salvia miltiorrhiza. Subsequently, bioinformatics methods were employed to investigate the physicochemical properties, sequence characteristics, phylogenetic evolution, and expression regulation of these family members. Finally, qPCR was used to study the expression of LDH family members under different stresses. The result showed that a total of 12 SmLDH genes were identified and classified into 3 subfamilies based on evolutionary relationships and conserved motifs. The encoded proteins of SmLDH contained 318~456 amino acids with molecular weights ranging from 34.42 to 48.51 kD. The isoelectric points of SmLDHs varied greatly among members, and the proteins were mainly localized in chloroplasts and cytoplasm. Chromosomal localization showed that SmLDH1/2/3/4 were located on chromosome 1, SmLDH5/6/7 on chromosome 2, SmLDH8/9 on chromosome 4, and SmLDH10/11/12 on chromosome 8. miRNA target prediction analysis indicated that SmLDH5/6 were regulated by members of the smi-miR390 family, while SmLDH10/11 were targeted by smi-miR156-like. Promoter cis-acting element analysis showed that, besides anaerobic-inducible cis-elements, the promoter regions of LDH family members contained numerous stress-responsive cis-acting elements, as well as hormone-responsive elements for abscisic acid (ABA), auxin and other phytohormones. Transcriptome data and qRT-PCR analysis indicated that SmLDH1/4/6/10 exhibited relatively high expression in roots. Under flooding stress, SmLDH4/6 were upregulated at different stages, while SmLDH1 responded continuously during the detection period. Under salt stress, the expression of SmLDH6 was first upregulated and then downregulated, whereas SmLDH1/4 were inhibited. After polyethylene glycol (PEG)-simulated drought treatment, SmLDH4/6/10 were upregulated. Additionally, SmLDH6/10 were induced by GA₃. The root-highly expressed SmLDH1/4/6/10 in S. miltiorrhiza played roles under multiple stresses. SmLDH1 was critical in flooding stress, while SmLDH6 functions in various stresses including salt and gibberellin A₃ (GA₃). This study lays a foundation for further dissecting the functions of LDH family members and their roles in regulating stress resistance of S. miltiorrhiza, and provides theoretical references and gene resources for stress-tolerant molecular breeding of S. miltiorrhiza.

The single-petaled pink tuberose (Polianthes tuberosa) variety 'Sensation' is an excellent variety with excellent color and fragrance. However, during the flowering process, there are phenomena such as difficulty in petal expansion and abnormal flower opening (stiff flowers), and the color becomes severely lighter and whiter during the opening process and anthocyanin synthesis of P. tuberosa. Due to the scarcity of research on its functional genes, the key genes and molecular mechanisms regulating the flowering process and flower color are still unknown. Based on the transcriptome sequencing analysis of tuberose, the MYB86 gene was identified. Bioinformatics analysis showed that encoded protein of PtMYB86 gene (GenBank No. PZ156279) possessed typical conserved regions of homologous proteins. Expression characteristic analysis indicated that its expression level continuously increased during flower blooming. A constitutive expression vector was constructed, and transient overexpression in tuberose petals showed that PtMYB86 had dual functions in tuberose. On the one hand, transient overexpression of PtMYB86 could significantly promote petal expansion and accelerate flower blooming, effectively overcoming the problem of "stiff flowers" problem in cut and potted tuberoses during cultivation, production and transportation. On the other hand, transient overexpression of PtMYB86 in tuberose petals could significantly change the petal color, resulting in a shift from pink to lighter and whiter shades, indicating that PtMYB86 negatively regulated anthocyanin formation. This study provides important functional genes for elucidating the molecular mechanisms underlying flower blooming and dynamic changes in flower color in tuberose.

Mulberry (Morus alba) is an important economically and ecologically significant tree species. Leaf development directly influences mulberry leaves yield and quality, which is also one of the key indexes for identification and evaluation of mulberry varieties. The TCP transcription factor family plays pivotal roles in plant organogenesis and stress responses; however, its systematic characterization in mulberry has been limited to date. In this study, 22 TCP genes (MnTCPs) were identified in the mulberry genome, and their structural characteristics and expression patterns were systematically analyzed. Phylogenetic analysis classified the MnTCPs into 3 subfamilies—PCF, CIN and CYC/TB1. Genes within each subfamily exhibited conserved exon structures and motif compositions, whereas inter-subfamily differences were evident, including a characteristic amino acid deletion in the BASIC domain of CYC/TB1 subfamily members. Analysis of promoter cis-elements revealed that MnTCPs promoters contained abundant hormone-, light- and stress-responsive cis-elements. Expression analysis further revealed significant temporal and varietal divergence: in 'Luoyu 1', most MnTCPs showed peak expression at early developmental stages or exhibited minimal variation, whereas in 'Fengyuan1', the majority reached maximal expression in mature leaves. These findings suggested that MnTCPs might play critical roles in late-stage leaf development and adaptive responses. Overall, this study presents a genome-wide characterization of the TCP gene family in mulberry and provides a theoretical basis for elucidating their regulatory functions and advancing molecular breeding efforts.

The intestine is the largest barrier organ of the body, and its structural and functional homeostasis serve as a critical foundation for yaks (Bos grunniens) to tolerate hypoxic stress. To investigate the role of YAP1/β-catenin/HIF-1α signaling pathway-related factors in the hypoxic adaptation of the yak small intestine, this study used 5 juvenile yaks and 5 juvenile cattle (Bos taurus) as experimental subjects. qRT-PCR, Western blot, immunohistochemistry (IHC), and immunofluorescence (IF) were employed to detect the expression and distribution of Yes1-associated transcriptional regulator (YAP1), β-catenin, hypoxia-inducible factor-1α (HIF-1α), and the tight junction proteins claudin-1 and occludin in the duodenal, jejunal, and ileal tissues. The qRT-PCR and Western blot results demonstrated that the expression levels of all 5 factors were extremely significantly higher in the duodenum, jejunum, and ileum of yaks compared with cattle (P<0.01), suggesting that yaks may possess a stronger adaptive capacity to hypoxia in the small intestine. Additionally, in both yaks and cattle, the mRNA and protein expression levels of YAP1, β-catenin, HIF-1α, claudin-1, and occludin in the ileum were extremely significantly higher than those in the duodenum and jejunum (P<0.01). IHC and IF results revealed that YAP1, β-catenin, and HIF-1α were predominantly localized in the nuclei of crypt stem cells within the small intestinal mucosal epithelium, with scattered distribution also observed in the nuclei of fibroblasts and lymphocytes in the lamina propria. Claudin-1 and occludin were mainly distributed in the cytoplasm of absorptive cells and goblet cells in the small intestinal mucosal epithelium, as well as in fibroblasts, lymphocytes, and glandular goblet cells in the lamina propria. Furthermore, YAP1, β-catenin and HIF-1α were co-localized in the nuclei of stem cells at the base of small intestinal crypts together with the intestinal stem cell marker—leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5), suggesting that factors related to the YAP1/β-catenin/HIF-1α signaling pathway might play a protective role in the mucosal epithelium and crypt stem cells of yak small intestinal tissues. This study provides basic data for further exploration of the molecular mechanisms underlying hypoxic adaptation in the yak digestive tract.

The key to bull (Bos taurus) fertility lies in the development of testes and sperm production, with testosterone synthesis and secretion by Leydig cells influencing testicular physiological function. The transition protein 1 (TNP1) gene is highly expressed in adult bull testes; however, its impact on Leydig cells remains unclear. In this study, bovine Leydig cells were isolated and cultured, and overexpression and interference of TNP1 were conducted. The effects of TNP1 on cell proliferation, apoptosis, and testosterone synthesis were assessed by qRT-PCR, Western blot, 5-ethynyl-2'-deoxyuridine (EdU) staining, flow cytometry, and ELISA. The results showed that overexpression of TNP1 significantly upregulated the expression of proliferation-related genes proliferating cell nuclear antigen (PCNA) and cyclin-dependent kinase 2 (CDK2)(P<0.05); extremely significantly increased the proportion of cells in an active proliferative state; downregulated the expression of apoptosis-related gene B-cell lymphoma-2 associated X protein (BAX) (P<0.01), extremely significant reduced the apoptosis rate; upregulated the expression of testosterone synthesis-related genes cytochrome P450 family 17 subfamily A member 1 (CYP17A1), 17 β-hydroxysteroid dehydrogenase 3 (HSD17B3), and steroidogenic acute regulatory protein (STAR) as well as testosterone levels (P<0.01). Conversely, interference of TNP1 extremely significantly downregulated the expression of PCNA and CDK2 (P<0.01), decreased the proportion of cells in an active proliferative state; upregulated the expression of BAX (P<0.01), significantly increased the apoptosis rate; downregulated the expression of CYP17A1, HSD17B3, and STAR as well as testosterone levels (P<0.05). These results indicated that TNP1 promoted proliferation and testosterone synthesis while inhibiting apoptosis in bovine Leydig cells. This study provides a foundation for exploring the mechanism by which TNP1 regulates bovine Leydig cells and offers a theoretical basis for enhancing the reproductive performance of bulls.

Insulin-like growth factor 1 receptor (IGF1R) belongs to the insulin receptor family and plays a vital role in multiple biological processes. To investigate the impact of polymorphisms in exon 2 of the IGF1R gene on growth traits in yaks (Bos grunniens) on the Qinghai Plateau, this study examined 400 yaks as research subjects. Single nucleotide polymorphism (SNP) detection and genetic analysis of this region were performed using DNA sequencing and haplotype typing techniques. The results identified 4 SNPs within exon 2 (g.7167773C>T, g.7167851C>T, g.7167890C>T, and g.7167938G>A), among which g.7167938G>A conformed to Hardy-Weinberg equilibrium, while the other loci exhibited disequilibrium. Polymorphism information content (PIC) analysis revealed that g.7167773C>T and g.7167938G>A were moderately polymorphic, indicating good genetic potential. Association analysis demonstrated that these loci were significantly correlated with yak growth traits (P<0.05). Specifically, individuals with the TT genotype at the g.7167773C>T locus exhibited extremely significantly superior performance across all growth metrics compared with other genotypes (P<0.01). At the g.7167938G>A locus, individuals with GA and AA genotypes had an extremely significantly higher body weight than those with GG genotype (P<0.01). Meanwhile, the slant body length of individuals with GA genotype was also extremely significantly greater than that of GG genotype individuals (P<0.01). Further analysis revealed that the 4 loci formed 7 haplotypes (Hap1~Hap7), with Hap2 being the dominant haplotype (frequency: 0.420). Based on this, diplotype analysis identified 9 combinations. Association analysis indicated that individuals with the diplotype combination H6H7 had extremely significantly higher body weight, withers height, body length, chest girth, and cannon bone circumference than other combinations (P<0.01), suggesting that H6H7 might represent the optimal diplotype combination influencing yak growth traits, and could serve as potential molecular markers for the selection of growth traits in yaks. This study provides a theoretical basis for genetic improvement and molecular breeding of plateau yaks.

Follicular atresia is a key physiological process affecting ovarian reserve and fertility. This study aimed to delineate the molecular mechanisms underlying atretic granulosa cells (AGC) in sheep (Ovis aries) and to evaluate the role of protein lactylation regulation in this process. Based on Gene Expression Omnibus (GEO), differentially expressed genes (DEGs) between AGC and healthy granulosa cells (HGC) were identified and subjected to KEGG pathway enrichment. Weighted gene co-expression network analysis (WGCNA) was performed to construct gene modules associated with the atresia phenotype. Candidate regulators were further mined by integrating protein-protein interaction (PPI) networks with a lactylation-related gene set. Ovine HGC and AGC were collected to measure lactate dehydrogenase (LDH) levels, and key genes were validated by RT-qPCR and Western blot. In vitro, granulosa cells (GCs) were treated with Na-lactate and transduced to overexpress LGALS1, yielding 4 groups: GC, GC+Na-lactate, GC+Na-lactate+OE-NC, and GC+Na-lactate+OE-LGALS1. Cell proliferation (CCK-8), apoptosis (TUNEL), migration/invasion (Transwell), and LDH release (ELISA) were assessed. Adhesion/EMT (epithelial-mesenchymal transition) markers (αVβ3, E-cadherin, N-cadherin, ICAM-1, VCAM-1) were examined by RT-qPCR/Western blot, and pathway proteins (FAK, p-FAK, Src, p-Src, MMP-2, MMP-9) were examined by Western blot. Results showed that a total of 726 DEGs were identified and were enriched mainly in cell adhesion molecule pathways. WGCNA revealed a module closely associated with atretic GCs, from which 22 hub genes were obtained via PPI analysis. Intersecting these with 12 lactylation-related DEGs pinpointed LGALS1 as a key candidate gene, which was highly expressed in HGC and functionally linked to cell adhesion, immune regulation, and apoptosis. In primary samples, the LDH level in the AGC group was extremely significantly higher than that in the HGC group (P<0.001), whereas the expression level of LGALS1 was extremely significantly decreased (P<0.001). In vitro experiments showed that Na-lactate treatment decreased proliferation, increased apoptosis, and weakened migration/invasion, accompanied by downregulation of E-cadherin, upregulation of αVβ3/N-cadherin/ICAM-1/VCAM-1, and activation of the FAK/Src-MMP axis. Under the same conditions, LGALS1 overexpression enhanced proliferation, reduced apoptosis, impaired migration and invasion capacity, upregulated E-cadherin, downregulated αVβ3 and related markers, and suppressed p-FAK, p-Src, MMP-2, and MMP-9. Experimental results indicated that LGALS1 might serve as a lactylation-associated key regulator in the granulosa-cell atresia process. This study provides a potential molecular target and theoretical basis for elucidating adhesion-mediated mechanisms of follicular atresia and for developing fertility-preserving interventions.

T-2 toxin is a highly toxic Fusarium toxin commonly found in grains and feed. It can activate apoptosis pathways by inducing oxidative stress and mitochondrial dysfunction, and damage important organs. The kidney, as a key organ for toxin metabolism and excretion, is more vulnerable to attack. However, effective protective strategies against its nephrotoxicity are still limited. As a phenolic antioxidant, tertiary butylhydroquinone (TBHQ) can activate the Nrf2/HO-1 pathway and counteract oxidative stress and apoptosis. Therefore,this study aims to investigate the protective effect of TBHQ against T-2 toxin-induced nephrotoxicity in male rats and to explore its molecular mechanisms. 40 male SD rats (Rattus norvegicus) were divided into Control group, T-2 group (T-2 toxin only), TBHQ+T-2 group (TBHQ i.p. for 14 d, followed by T-2 gavage for 7 d), and M group (simultaneous TBHQ and T-2 for 7 d). End-point analysis included serum markers (SCR, Cys-C, β₂-MG), renal oxidative stress (SOD, CAT, GSH-PX, TAC, MDA), antioxidant gene expression (Sod,Cat,Gpx), histopathology (HE, Masson, PAS staining), and the cell apoptosis rate (TUNEL). The results showed that compared with Control group, serum levels of SCR and Cys-C were significantly elevated in rats of the T-2 group (P<0.05); renal SOD and MDA contents as well as the renal cell apoptosis rate were significantly increased (P<0.05), accompanied by damage to renal structure. However, TBHQ pretreatment significantly reversed these pathological changes: It reduced serum renal markers and MDA content (P<0.05), markedly reduced cell apoptosis (P<0.01), significantly improved histopathological lesions, and upregulated the mRNA expression of antioxidant genes Gpx (P<0.05) compared with the T-2 group. Furthermore, the protective effect of the TBHQ pretreatment regimen was superior to the M group. In conclusion, TBHQ mitigated T-2 toxin-induced renal injury in male rats by enhancing its anti-oxidative stress and anti-apoptotic effects, with pretreatment offering a more effective strategy. This study provides experimental evidence for elucidating the oxidative stress apoptosis mechanism of T-2 toxin nephrotoxicity as well as theoretical references for preventive protective measures against feed mycotoxin related kidney injury.

Adipocyte fatty acid-binding protein (AFABP), a member of the fatty acid-binding protein family, is predominantly expressed in adipocytes, macrophages, and endothelial cells. While traditionally regarded as an intracellular fatty acid transporter, mammalian AFABP has been identified as a secretory adipokine that regulates systemic metabolism via the circulatory system. However, it remains unclear whether chicken (Gallus gallus) AFABP exhibits similar secretory property and possesses extracellular functions. In this study, Western blot analysis was used to verify the secretory capacity of chicken AFABP; CCK8 and RT-qPCR assays were used to examine its effect on chicken preadipocyte proliferation. Western blot analysis showed that chicken AFABP protein was present in the culture supernatants of the transfected cells, indicating that AFABP possessed secretory property. CCK8 and RT-qPCR assays revealed that the secreted chicken AFABP promoted preadipocyte proliferation. This study provides a foundation for further investigation into the function and mechanism of chicken AFABP.

Hemibagrus guttatus is a rare freshwater fish species, sexual dimorphism is the basis of its reproduction, but the mechanism of sex differentiation in H. guttatus remains unclear. The cytochrome P450 family 19 subfamily A member 1A(cyp19a1a) is a critical gene that influences estrogen biosynthesis and is essential for both sex differentiation and ovarian development. To investigate the mechanism of the cyp19a1a gene in sex differentiation of H. guttatus, qPCR was used to analyze the expression levels of cyp19a1a in different tissues, at different developmental stages, and in the gonads of sex-reversed individuals. Fluorescence in situ hybridization (FISH) was employed to determine the expression of cyp19a1a in gonadal cells of H. guttatus. The results revealed that the ORF sequence of cyp19a1a in H. guttatus was 1 587 bp in length, encoding 528 amino acids, and contained conserved functional domains of the aromatase amino acid sequence. The qPCR results showed that cyp19a1a was expressed in all examined tissues of H. guttatus, with the highest expression levels in the gonads, followed by the brain and liver. The expression profile of cyp19a1a in pseudofemales was consistent with that of normal females at the same age. Moreover, the expression of cyp19a1a in ovaries was significantly higher than that in testes at corresponding stages (P<0.05) and gradually increased with gonadal development. FISH results showed that the signal for cyp19a1a was weaker in sperm and mature oocytes but stronger in oogonia and early oocytes. The above findings indicated that the cyp19a1a gene played an important role in gonadal development, germ cell growth, and sex reversal in H. guttatus. This study provides a reference for understanding the function of the cyp19a1a gene and the sex determination mechanisms in H. guttatus.

Cellulases are key catalysts for the efficient utilization of cellulose resources, but their insufficient catalytic efficiency and thermostability have seriously restricted their widespread application. In this study, endoglucanase EG-20SJ from the glycoside hydrolase family 5 (GH5), derived from Bacillus velezensis, was used as the research object. First, non-conservative sites in the loop region near the active center were screened through homology modeling and conservation analysis. Then, combined with alanine scanning and site-saturation mutagenesis, mutants were constructed, and their enzymatic properties were analyzed. Results showed that among the saturation mutants at the Asp99 and Ser264 sites, the single mutants D99R, S264R, and the double mutant D99R/S264R exhibited significantly improved activity. Specifically, the double mutant had an enzyme activity of 544.2 U/mg, which was 2.51 times that of the wild-type (217.1 U/mg). Regarding enzymatic properties, the optimal reaction temperature of the double mutant increased by 10 ℃ (reaching 60 ℃), and its residual activity after incubation at 70 ℃ for 1 h reached 61.7%. Kinetic analysis revealed a 44.0% reduction in michaelis constant (K_m) and a 1.2-fold higher catalytic constant (k_cat)/K_m, indicating significant improvements in substrate affinity and catalytic efficiency. Molecular docking results confirmed that Arg99 and Arg264 in the double mutant enhanced substrate binding through additional hydrogen bonds and stabilized the conformation of the loop region. This study revealed the regulatory mechanism of non-conservative loop sites on enzyme function, providing a theoretical basis for the molecular modification and broad application of GH5 family enzymes.

Yak pathogenic Escherichia coli (YPEC) is the primary causative agent of diarrhea, enterotoxemia, and mastitis in yaks (Bos grunniens) on the Qinghai-Tibet Plateau. To identify the pathogens causing diarrhea in yaks at a farm in Qinghai Province, and to analyze the phylogenetic grouping, antimicrobial resistance status and virulence characteristics of YPEC. Fecal samples from diarrheic yak calves were collected under aseptic conditions in this study. Pathogens were identified through isolation and culture, morphological observation, biochemical identification, and PCR detection of the E. coli specific phoA gene and 16S rRNA. Subsequently, phylogenetic tree construction, evolutionary grouping, K-B method antimicrobial susceptibility testing, PCR identification of resistance and virulence genes, and mouse (Mus musculus) pathogenicity tests were employed to analyze their biological characteristics. The results showed that 4 E. coli strains were isolated, identified, and named Qinghai-1 (QH-1), Qinghai-2 (QH-2), Qinghai-3 (QH-3) and Qinghai-4 (QH-4). Phylogenetic tree results showed QH-1, QH-2, QH-3, and QH-4 clustered into a small group, suggesting they likely evolved from a common ancestor with close phylogenetic relationships. Among them, QH-2 and QH-4 belonged to the same branch and were most closely related. Phylogenetic grouping results indicated that QH-1 and QH-4 belonged to group D, while QH-2 and QH-3 were classified in group B2. 4 E. coli strains exhibited multidrug resistance (resistance to ≥11 drugs), with 100% resistance to sulfonamides and glycopeptides. Among the drug resistance genes, 4 E. coli strains showed detection of resistance genes in 7 major classes of antimicrobial agents, excluding amides. Notably, the positive rates of the resistance genes blaCIT, blaTEM, and VanA were 100%. Among the virulence genes, 4 E. coli strains carried 7 virulence genes including F17, csgA and irp2, whereas 11 virulence genes such as K88, ST1, and LT1 were all negative. The challenge test results showed that mice began to exhibit clinical symptoms 12 h post infection, and all animals in the experimental group died within 96 h, indicating that the 4 E. coli strains were all YPEC. Histopathological examination revealed varying degrees of pathological changes in the spleen and lung tissues of mice. Taken together, this study confirmed that the pathogen responsible for diarrhea in yaks at a yak farm in Qinghai Province was YPEC. The 4 isolated YPEC strains carried multiple virulence and antimicrobial resistance genes, exhibited multidrug resistant phenotypes and pathogenicity, and phylogenetic homology analysis suggested a potential transmission risk of YPEC within yak farms in Qinghai Province. This study provides a scientific basis for the precise use and effective control of YPEC antibiotics in pastoral areas of the Tibetan Plateau.

As the most widely cultivated grain crop, the safe production of rice (Oryza sativa) is vital to the staple food source for nearly half of the global population. With the promotion of the simplified cultivation model, the planting area of direct seeding rice has continued to expand. However, the outbreak of drug-resistant weed populations such as Leptochloa chinensis and Echinochloa crus-galli has become a key biological stress factor restricting the improvement of rice yield and quality. Chemical weed control, as the primary method of management, faces issues such as limited selectivity, evolution of weed resistance, and ecological residue. This review summarized the molecular mechanisms of herbicide resistance in rice and recent advances in molecular breeding for herbicide-resistant rice varieties, while also analyzing technical bottlenecks and challenges in current herbicide application. The aim is to provide insights for the development and industrialization of herbicide-resistant rice.

Sturgeon (Acipenseriformes) is one of the oldest groups of bony fish and holds an important position in the evolutionary history of vertebrates. Most sturgeon species follow a ZW-type female heterogametic sex-determination system, although this is not the only mechanism involved. Slow progress in sturgeon sex differentiation research is attributed to the lack of obvious sexual dimorphism and the long gonadal development cycle. In recent years, various techniques have been employed to screen for candidate genes associated with sex in sturgeon, but no major sex-determining gene has been identified. Since female sturgeon produce roe with higher market value, research into sex control mechanisms has significant potential for applications in breeding and sex regulation. This review systematically summarizes research on sex determination and differentiation in sturgeon, with a focus on the role of transcription factors and transforming growth factor-beta (TGF-β) family genes in the process of sex determination and differentiation. The aim is to provide insights into sturgeon sex determination and differentiation, deepen our understanding of the evolutionary history of sex determination mechanisms in vertebrates, and provide a theoretical basis for sex control breeding in sturgeon.

Choosing appropriate reference genes is crucial for enhancing the accuracy of real-time fluorescence quantitative PCR (qRT-PCR) analysis results. To screen for stable expression of internal reference genes suitable for heat stress in Chinese flowering cabbage (Brassica campestris ssp. chinensis var. utilis), this study selected 16 candidate reference genes based on RNA-seq data. The expression stability of these genes was evaluated using GeNorm, NormFinder, BestKeeper, and RefFinder at different times, tissues, and cultivars under heat stress.The results showed that casein kinaseⅠ (CKⅠ) exhibited optimal expression stability under different time and tissue treatments of heat stress; The gene with the most stable expression among different cultivars under heat stress was 28S ribosomal protein S27 (28SRPS27). The comprehensive analysis of all heat stress samples shows that CKⅠ has the best overall stability. The validation experiment confirmed that using CKⅠ as an internal reference gene effectively and accurately quantifies the expression changes of heat-responsive genes, indicating its suitability for standardizing qRT-PCR data related to heat stress in Chinese flowering cabbage. This study identified stable reference genes suitable for heat stress in Chinese flowering cabbage, and providing a basis for functional analysis of heat-resistant genes and molecular breeding in the future.