1.Trend analysis of pulmonary tuberculosis incidence among the elderly in Shanghai, 2014‒2023
Yu HUANG ; Lixin RAO ; Biao XU ; Qi ZHAO ; Xin SHEN
Shanghai Journal of Preventive Medicine 2025;37(3):227-233
ObjectiveTo describe the epidemiological characteristics and trend of pulmonary tuberculosis among the elderly in Shanghai from 2014 to 2023, to estimate the incidence between 2024‒2025, so as to provide references for optimizing the prevention and control strategies of pulmonary tuberculosis for elderly in Shanghai. MethodsData of pulmonary tuberculosis patients aged ≥60 years in Shanghai registered in the Tuberculosis Registration and Management System of Chinese Center for Disease Control and Prevention from 2014 to 2023 was derived to describe the demographic characteristics of the elderly patients with pulmonary tuberculosis, and to calculate the reported incidence rate and annual percentage change (APC) of pulmonary tuberculosis. The autoregressive integrated moving average (ARIMA) model was constructed using monthly reported incidence data from January 2014 to June 2023, and data from July to December in 2023 were used to validate the model and predict the reported incidence rate of pulmonary tuberculosis among elderly in 2024 and 2025. ResultsA total of 19 208 elderly pulmonary tuberculosis patients were registered and reported in Shanghai from 2014 to 2023, with an average annual reported incidence rate of 35.04/100 000. The reported incidence rate of pulmonary tuberculosis in elderly showed an overall decreasing trend, APC=-3.34% (t=-3.360,P=0.010). While, the proportion of elderly pulmonary tuberculosis patients showed a yearly increasing trend among the total registered and reported cases, APC=5.65% (t=10.820, P<0.001). The difference in the average annual reported incidence rate of pulmonary tuberculosis in elderly was statistically significant in different regions (χ2=31.762, P=0.007), with the central urban areas(33.23/100 000) being lower than that in suburban areas (36.46/100 000), and the annual decreasing rate was faster in central urban area, APC=-4.88% (t=-4.838, P<0.001) and -2.76% (t=-2.811, P=0.023), respectively. The incidence rate was significantly higher in males than that in females (χ2=514.395, P<0.001). Additionally, the difference in reported incidence rate was statistically significant among different age groups(χ2=119.751,P<0.001), among which patients aged ≥80 years had the highest average annual incidence rate (59.69/100 000), and those aged ≤60 years had the lowest average annual incidence rate (28.57/100 000). Compared with the non-residential permanent elderly population (47.68/100 000), the average annual incidence rate of pulmonary tuberculosis among the elderly with household registration in Shanghai was lower (33.82/100 000) (χ2=24.295, P<0.001). The ARIMA (0,0,1) (0,1,1) 12 model was used to predict the incidence rate of pulmonary tuberculosis among the elderly in Shanghai in 2024 and 2025, and which was predicted to be 37.41/100 000 and 35.92/100 000, respectively. ConclusionThe reported incidence rate of pulmonary tuberculosis among the elderly in Shanghai showed an overall yearly downward trend from 2014 to 2023, but its proportion in the total number of reported pulmonary tuberculosis cases increased year by year. Prevention and control efforts should still not be slackened and emphasis should be placed on male, suburban and non-residential permanent elderly populations.
2.Single-cell and spatial transcriptomic analysis reveals that an immune cell-related signature could predict clinical outcomes for microsatellite-stable colorectal cancer patients receiving immunotherapy.
Shijin YUAN ; Yan XIA ; Guangwei DAI ; Shun RAO ; Rongrong HU ; Yuzhen GAO ; Qing QIU ; Chenghao WU ; Sai QIAO ; Yinghua XU ; Xinyou XIE ; Haizhou LOU ; Xian WANG ; Jun ZHANG
Journal of Zhejiang University. Science. B 2025;26(4):371-392
Recent data suggest that vascular endothelial growth factor receptor inhibitor (VEGFRi) can enhance the anti-tumor activity of the anti-programmed cell death-1 (anti-PD-1) antibody in colorectal cancer (CRC) with microsatellite stability (MSS). However, the comparison between this combination and standard third-line VEGFRi treatment is not performed, and reliable biomarkers are still lacking. We retrospectively enrolled MSS CRC patients receiving anti-PD-1 antibody plus VEGFRi (combination group, n=54) or VEGFRi alone (VEGFRi group, n=32), and their efficacy and safety were evaluated. We additionally examined the immune characteristics of the MSS CRC tumor microenvironment (TME) through single-cell and spatial transcriptomic data, and an MSS CRC immune cell-related signature (MCICRS) that can be used to predict the clinical outcomes of MSS CRC patients receiving immunotherapy was developed and validated in our in-house cohort. Compared with VEGFRi alone, the combination of anti-PD-1 antibody and VEGFRi exhibited a prolonged survival benefit (median progression-free survival: 4.4 vs. 2.0 months, P=0.0024; median overall survival: 10.2 vs. 5.2 months, P=0.0038) and a similar adverse event incidence. Through single-cell and spatial transcriptomic analysis, we determined ten MSS CRC-enriched immune cell types and their spatial distribution, including naive CD4+ T, regulatory CD4+ T, CD4+ Th17, exhausted CD8+ T, cytotoxic CD8+ T, proliferated CD8+ T, natural killer (NK) cells, plasma, and classical and intermediate monocytes. Based on a systemic meta-analysis and ten machine learning algorithms, we obtained MCICRS, an independent risk factor for the prognosis of MSS CRC patients. Further analyses demonstrated that the low-MCICRS group presented a higher immune cell infiltration and immune-related pathway activation, and hence a significant relation with the superior efficacy of pan-cancer immunotherapy. More importantly, the predictive value of MCICRS in MSS CRC patients receiving immunotherapy was also validated with an in-house cohort. Anti-PD-1 antibody combined with VEGFRi presented an improved clinical benefit in MSS CRC with manageable toxicity. MCICRS could serve as a robust and promising tool to predict clinical outcomes for individual MSS CRC patients receiving immunotherapy.
Humans
;
Colorectal Neoplasms/drug therapy*
;
Male
;
Female
;
Immunotherapy
;
Middle Aged
;
Aged
;
Tumor Microenvironment/immunology*
;
Retrospective Studies
;
Microsatellite Instability
;
Transcriptome
;
Single-Cell Analysis
;
Programmed Cell Death 1 Receptor/immunology*
;
Gene Expression Profiling
;
Immune Checkpoint Inhibitors/therapeutic use*
;
Adult
;
Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors*
3.Mechanism of auraptene in improving acute liver injury induced by diquat poisoning in mice.
Renyang OU ; Shan HUANG ; Lihong MA ; Zhijie ZHAO ; Shengshan LIU ; Yuanliang WANG ; Yezi SUN ; Nana XU ; Lijun ZHOU ; Mei LI ; Manhong ZHOU ; Guosheng RAO
Chinese Critical Care Medicine 2025;37(6):590-594
OBJECTIVE:
To investigate whether auraptene (AUR) exerts a protective effect on acute diquat (DQ)-induced liver injury in mice and explore its underlying mechanisms.
METHODS:
Forty SPF-grade healthy male C57BL/6 mice were randomly divided into normal control group (Control group), DQ poisoning model group (DQ group), AUR treatment group (DQ+AUR group), and AUR control group (AUR group), with 10 mice in each group. The DQ poisoning model was established via a single intraperitoneal injection of 40 mg/kg DQ aqueous solution (0.5 mL); Control group and AUR group received an equal volume of pure water intraperitoneally. Four hours post-modeling, DQ+AUR group and AUR group were administered 0.5 mg/kg AUR aqueous solution (0.2 mL) by gavage once daily for 7 consecutive days, while Control group and DQ group received pure water. Blood and liver tissues were collected after anesthesia on day 7. Liver ultrastructure was observed by transmission electron microscopy. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured via enzyme-linked immunosorbent assay (ELISA). Hepatic glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected using WST-1, thiobarbituric acid (TBA), and enzymatic reaction methods, respectively. Protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues was analyzed by Western blotting.
RESULTS:
Transmission electron microscopy revealed that mitochondria in the Control group exhibited mild swelling, uneven distribution of matrix, and a small number of cristae fractures. In the AUR group, mitochondria showed mild swelling, with no obvious disruption of cristae structure. In the DQ group, mitochondria demonstrated marked swelling and increased volume, matrix dissolution, loss and fragmentation of cristae, and extensive vacuolization. In contrast, the DQ+AUR group showed significantly reduced mitochondrial swelling, volume increase, matrix dissolution, cristae loss and fragmentation, and vacuolization compared to the DQ group. Compared with the DQ group, the DQ+AUR group exhibited significantly lower serum AST levels (U/L: 173.45±23.60 vs. 255.33±41.51), ALT levels (U/L: 51.77±21.63 vs. 100.70±32.35), and hepatic MDA levels (μmol/g: 12.40±2.76 vs. 19.74±4.10), along with higher hepatic GSH levels (mmol/g: 37.65±14.95 vs. 20.58±8.52) and SOD levels (kU/g: 124.10±33.77 vs. 82.81±22.00), the differences were statistically significant (all P < 0.05). Western blotting showed upregulated Nrf2 expression (Nrf2/β-actin: 0.87±0.37 vs. 0.53±0.22) and HO-1 expression (HO-1/β-actin: 1.06±0.22 vs. 0.49±0.08), and downregulated Keap1 expression (Keap1/β-actin: 0.82±0.12 vs. 1.52±0.76) and activated caspase-9 expression (activated caspase-9/β-actin: 1.16±0.28 vs. 1.71±0.30) in the DQ+AUR group compared to the DQ group (all P < 0.05).
CONCLUSION
AUR attenuates DQ-induced acute liver injury in mice by activating the Keap1/Nrf2 signaling pathway.
Animals
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Male
;
Mice
;
Mice, Inbred C57BL
;
Liver/pathology*
;
Chemical and Drug Induced Liver Injury/drug therapy*
;
Diquat/poisoning*
;
NF-E2-Related Factor 2/metabolism*
;
Oxidative Stress
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Apoptosis
;
Coumarins
4.Therapeutic role of Prunella vulgaris L. polysaccharides in non-alcoholic steatohepatitis and gut dysbiosis.
Meng-Jie ZHU ; Yi-Jie SONG ; Pei-Li RAO ; Wen-Yi GU ; Yu XU ; Hong-Xi XU
Journal of Integrative Medicine 2025;23(3):297-308
OBJECTIVE:
Prunella vulgaris L. has long been used for liver protection according to traditional Chinese medicine theory and has been proven by modern pharmacological research to have multiple potential liver-protective effects. However, its effects on non-alcoholic steatohepatitis (NASH) are currently uncertain. Our study explores the effects of P. vulgaris polysaccharides on NASH and intestinal homeostasis.
METHODS:
An aqueous extract of the dried fruit spikes of P. vulgaris was precipitated in an 85% ethanol solution (PVE85) to extract crude polysaccharides from the herb. A choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) was administrated to male C57BL/6 mice to establish a NASH animal model. After 4 weeks, the PVE85 group was orally administered PVE85 (200 mg/[kg·d]), while the control group and CDAHFD group were orally administered vehicle for 6 weeks. Quantitative real-time polymerase chain reaction analysis, Western blotting, immunohistochemistry and other methods were used to assess the impact of PVE85 on the liver in mice with NASH. 16S rRNA gene amplicon analysis was employed to evaluate the gut microbiota abundance and diversity in each group to examine alterations at various taxonomic levels.
RESULTS:
PVE85 significantly reversed the course of NASH in mice. mRNA levels of inflammatory mediators associated with NASH and protein expression of hepatic nucleotide-binding leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) were significantly reduced after PVE85 treatment. Moreover, PVE85 attenuated the thickening and cross-linking of collagen fibres and inhibited the expression of fibrosis-related mRNAs in the livers of NASH mice. Intriguingly, PVE85 restored changes in the gut microbiota and improved intestinal barrier dysfunction induced by NASH by increasing the abundance of Actinobacteria and reducing the abundance of Proteobacteria at the phylum level. PVE85 had significant activity in reducing the relative abundance of Clostridiaceae at the family levels. PVE85 markedly enhanced the abundance of some beneficial micro-organisms at various taxonomic levels as well. Additionally, the physicochemical environment of the intestine was effectively improved, involving an increase in the density of intestinal villi, normalization of the intestinal pH, and improvement of intestinal permeability.
CONCLUSION
PVE85 can reduce hepatic lipid overaccumulation, inflammation, and fibrosis in an animal model of CDAHFD-induced NASH and improve the intestinal microbial composition and intestinal structure. Please cite this article as: Zhu MJ, Song YJ, Rao PL, Gu WY, Xu Y, Xu HX. Therapeutic role of Prunella vulgaris L. polysaccharides in non-alcoholic steatohepatitis and gut dysbiosis. J Integr Med. 2025; 2025; 23(3): 297-308.
Animals
;
Non-alcoholic Fatty Liver Disease/drug therapy*
;
Male
;
Dysbiosis/drug therapy*
;
Mice, Inbred C57BL
;
Gastrointestinal Microbiome/drug effects*
;
Polysaccharides/therapeutic use*
;
Prunella/chemistry*
;
Mice
;
Liver/metabolism*
;
Plant Extracts/therapeutic use*
;
Disease Models, Animal
;
Diet, High-Fat
5.Map-based cloning and abiotic stress response analysis of rust spotted leaf 1 in rice.
Jun LIU ; Xiaoyan LIU ; Yiyun GE ; Yiting WEI ; Kangjie LING ; Luyao TANG ; Jiangmin XU ; Yuchun RAO
Chinese Journal of Biotechnology 2025;41(7):2871-2884
Rice (Oryza sativa L.) is an important food crop. The appearance of lesion mimics in rice leads to phytohormone disorders, which affects rice adaptation to environmental stresses and ultimately reduces the yield and quality. To explore whether the changes in the adaptability of rice lesion-mimic mutants to stressful environments are caused by the disorder of phytohormone metabolism in plants. In this study, we screened an ethyl methane sulfonate-treated population of the japonica cultivar 'Taipei 309' for a mutant with rust-like spots on leaves at the early tillering stage and brown-red spots at maturity and named it rsl1 (rust spotted leaf 1). Compared with the wild type, rsl1 showed decreases in plant height, panicle length, primary branch number, secondary branch number, filled grains per panicle, seed-setting rate, and 1 000-grain weight, and an increase in number of effective panicles. Genetic analysis indicated that rsl1 was controlled by a single recessive nuclear gene. RSL1 was localized between two molecular markers, B7-7 and B7-9, on rice chromosome 7 by map-based cloning. PCR sequencing of the annotated genes in this interval revealed a mutation of C1683A on the eighth exon of SPL5 (LOC_Os07g10390) in rsl1, which resulted in premature termination of protein translation. Exogenous phytohormone treatments showed that rsl1 was less sensitive to salicylic acid (SA), abscisic acid (ABA), and indo-3-acetic acid (IAA) and more sensitive to methyl jasmonate (MeJA) and gibberellin acid (GA) than the wild type. In addition, the survival rate of rsl1 was lower than that of the wild type under salt, alkali, drought, and high temperature stresses, and it was higher than that of the wild type under cold stress. Quantitative real-time polymerase chain reaction (qRT-PCR) results showed that RSL1 was involved in the regulation of ABA, SA, MeJA, IAA, and GA-related genes under abiotic stresses. The present study showed that the RSL1 mutation led to the appearance of lesion mimics and affected the growth, development, and stress resistance of rsl1 under abiotic stresses. The study of the functional mechanism of this gene can provide theoretical guidance for the research on rice stress resistance.
Oryza/microbiology*
;
Stress, Physiological/genetics*
;
Plant Diseases/genetics*
;
Cloning, Molecular
;
Chromosome Mapping
;
Plant Growth Regulators/metabolism*
;
Plant Proteins/genetics*
;
Mutation
;
Cyclopentanes
;
Genes, Plant
;
Plant Leaves/genetics*
;
Oxylipins
6.Metabolic engineering of Escherichia coli for de novo synthesis of L-theanine.
Siquan ZHOU ; Di ZHANG ; Meijuan XU ; Xian ZHANG ; Taowei YANG ; Zhiming RAO
Chinese Journal of Biotechnology 2025;41(9):3459-3472
L-theanine is an important natural non-protein amino acid that is widely used in food and medicine. Although in previous studies, a microbial fermentation method for L-theanine without the addition of ethylamine has been developed, the conversion rate of this process needs to be further improved. In this study, we constructed a de novo synthesis pathway of L-theanine with glucose as the substrate. First, an in vitro transformation pathway containing ω-transaminase (TA) and γ-glutamylmethylamide synthetase (GMAS) was designed, optimized, and introduced into the chassis strain Escherichia coli K12 W3110 to achieve de novo synthesis of L-theanine. To improve the synthesis efficiency through metabolic engineering, we increased the copies of the GMAS gene gams and the TA gene spuC and enhanced the expression of the aldehyde dehydrogenase gene eutE to provide sufficient acetaldehyde substrate, knocked out the lactate dehydrogenase gene ldhA and the pyruvate formate lyase gene pflB to block bypass metabolism, and introduced the alanine dehydrogenase gene alD to recycle alanine. Furthermore, we over-expressed the phosphoenolpyruvate carboxylase gene ppc to enhance the carbon flux of the TCA cycle, knocked out the succinyl-CoA synthase gene sucCD to reduce the loss of downstream flux of TCA, and integrated the glutamate dehydrogenase gene gdh to enhance the supply of L-glutamate. Finally, the polyphosphate kinase gene ppk was introduced to the ATP cycle, which enhanced the energy supply in L-theanine production. The recombinant strain Tea11 produced 22.60 g/L L-theanine in a 5 L fermenter in 28 h, with a conversion rate of 41.71%. This synthetic pathway in this study balanced the relationship between the supply of ethylamine and the production of theanine, providing a new idea for metabolic engineering of microorganisms to produce L-theanine.
Glutamates/biosynthesis*
;
Metabolic Engineering/methods*
;
Escherichia coli/genetics*
;
Fermentation
;
Transaminases/metabolism*
;
Amide Synthases/metabolism*
;
Glucose/metabolism*
7.Whole-cell catalytic synthesis of β-hydroxy-β-methylbutyric acid by constructing recombinant Escherichia coli.
Jiawei YE ; Hong XU ; Yaxin LIAO ; Zhiming RAO ; Meijuan XU
Chinese Journal of Biotechnology 2025;41(9):3487-3503
β-hydroxy-β-methylbutyric acid (HMB) is widely applied in sports nutrition, disease prevention and other fields. However, chemical synthesis methods, limited by toxic reagents and violent reactions, can hardly meet the demands of green production. The biosynthesis method mainly utilizes enzymatic catalysis or metabolic engineering techniques for synthesis, and has the advantages of high efficiency, low cost, and sustainability. Therefore, the production of HMB by the biosynthesis method has a good application prospect. In this research, a biosynthesis-based production strategy for HMB was developed. By using L-leucine as the substrate and constructing a dual-enzyme co-expression system, we established an efficient catalytic process. At first, the enzymatic properties of L-amino acid deaminase (PvL-AAD) from Proteus vulgaris and 4-hydroxyphenylpyruvate dioxygenase (Rn4-HPPD) from Rattus norvegicus were characterized. Rn4-HPPD had low relative activity and required an acidic environment for catalysis. Based on the surface charge modification strategy of the enzyme protein, site-directed mutagenesis and combinatorial mutagenesis were conducted on 10 sites of Rn4-HPPD. A double mutant Rn4-HPPDH18R/N302R was thus obtained, with the enzyme activities being 2.00 times and 2.39 times that of the wild type at pH 5.5 and pH 6.5, respectively. Subsequently, the expression of the two enzymes in Escherichia coli was optimized. After the optimal expression ratio of the two enzymes was determined as 1:3 and under the conditions of OD600 of 70, pH 6.0, 35 ℃, Fe2+ concentration of 1.5 mmol/L, and feeding of the substrate in batches in a 5 L fermenter, the maximum yield of HMB reached 8.60 g/L. This study not only enhances the optimal pH and activity of Rn4-HPPD but also provides new approaches for the efficient microbial synthesis of HMB.
Escherichia coli/metabolism*
;
Valerates/metabolism*
;
Recombinant Proteins/biosynthesis*
;
Animals
;
Metabolic Engineering/methods*
;
Rats
;
Catalysis
8.Whole-cell transformation for the synthesis of tyrosine by a multi-enzyme cascade.
Fei YANG ; Yue WANG ; Xuanping SHI ; Jiajia YOU ; Minglong SHAO ; Meijuan XU ; Zhiming RAO
Chinese Journal of Biotechnology 2025;41(9):3537-3552
L-tyrosine is one of the 20 amino acids that make up proteins and is an essential amino acid for mammals, often used as a nutritional supplement. The conventional methods for synthesizing L-tyrosine have some problems such as the production of many by-products, high requirements for production conditions, and environmental pollution. In this study, we designed and constructed a multi-enzyme cascade for the synthesis of L-tyrosine with alanine, glutamate, ammonium chloride, and phenol as substrates. Initially, the sources of glutamate oxidase, alanine aminotransferase, and tyrosine phenol lyase were screened and analyzed, which was followed by the identification of the rate-limiting enzyme in the reaction process. A colorimetric screening method was established, and the rate-limiting enzyme DbAlaA was engineered to enhance its activity by 40.0%. Subsequently, the reaction conditions, including temperature, pH, cell concentration, and surfactant and coenzyme dosages, were optimized. After optimization, the yield of L-tyrosine reached 9.93 g/L, with a alanine conversion rate of 54.90%. Finally, a feed-batch fermentation strategy was adopted, and the yield of L-tyrosine reached 56.07 g/L after 24 h, with a alanine conversion rate of 65.22%. This study provides a reference for the whole-cell catalytic synthesis of L-tyrosine and its industrialization.
Tyrosine/biosynthesis*
;
Escherichia coli/metabolism*
;
Tyrosine Phenol-Lyase/genetics*
;
Multienzyme Complexes/metabolism*
;
Fermentation
9.Application and prospects of synthetic biology in the genetic improvement of rice.
Luyao TANG ; Yiting WEI ; Yuqing XU ; Yuexing WANG ; Yuchun RAO
Chinese Journal of Biotechnology 2025;41(10):3840-3862
Synthetic biology, recognized as one of the most revolutionary interdisciplinary fields in the 21st century, has established innovative strategies for the genetic improvement of rice through the integration of multidisciplinary technologies including genome editing, genetic circuit design, metabolic engineering, and artificial intelligence. This review systematically summarizes recent research advancements and breakthrough achievements in the application of synthetic biology in the genetic improvement of rice, focusing on three critical domains: yield improvement, nutritional quality fortification, and reinforcement of disease resistance and abiotic stress tolerance. It elucidates that synthetic biology enables precise genomic and metabolic pathway engineering through modular, standard, and systematic approaches, effectively overcoming the limitations of conventional breeding methods characterized by prolonged cycles and restricted trait modification capabilities. The implementation of synthetic biology has facilitated synergistic improvement of multi-traits, thereby providing critical technical references for developing elite rice cultivars with superior productivity and nutritional value. These technological breakthroughs hold significant implications for ensuring global food security and promoting green and sustainable development of agriculture.
Oryza/growth & development*
;
Synthetic Biology/methods*
;
Metabolic Engineering
;
Plant Breeding/methods*
;
Gene Editing
;
Genetic Engineering/methods*
;
Plants, Genetically Modified/genetics*
;
Disease Resistance/genetics*
10.Quantitative trait locus(QTL) mapping and candidate gene expression analysis of cold tolerance of rice at plumule and seedling stages.
Beibei ZHAO ; Zhining ZHANG ; Yanan JIANG ; Chengxiang HU ; Luyi ZHANG ; Jun LIU ; Jiangmin XU ; Yuexing WANG ; Yuchun RAO
Chinese Journal of Biotechnology 2025;41(10):3939-3955
Rice (Oryza sativa L.), as a thermophilic crop, is highly susceptible to cold stress during its growth process. Chilling injury at the plumule stage and seedling stage often affects the morphological development and leads to yield reduction of rice. The exploration and utilization of cold tolerance genes are among the most direct and effective approaches to address cold stress in rice. To identify quantitative trait loci (QTLs) associated with cold tolerance at plumule and seedling stages, in this study, we measured the seedling rates and survived seedling rates of the indica rice cultivar 'HZ', the japonica cultivar 'Nekken2', and their 120 recombinant inbred lines (RILs) under cold stress. A previously constructed high-density genetic linkage map was used for the mapping of the QTLs conferring cold tolerance at the plumule and seedling stages. A total of 4 QTLs for plumule-stage cold tolerance and 9 QTLs for seedling-stage cold tolerance were detected, with the maximum limit of detection reaching 5.20. Notably, a genetically overlapping QTL for both plumule and seedling stages was identified on chromosome 8, spanning a physical interval of 24 432 953-25 295 129 bp. Candidate genes within the detected QTL intervals were screened, and quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze the gene expression during the plumule and seedling stages. The results revealed that LOC_Os03g06570, LOC_Os03g07100, LOC_Os06g08280, LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540 exhibited significantly differential expression between the parental lines. These genes were either significantly downregulated or upregulated under cold stress. Among them, the first three gene (LOC_Os03g06570, LOC_Os03g07100, and LOC_Os06g08280) were hypothesized to be key candidates regulating the cold tolerance of rice seedlings, while the latter three genes (LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540) were identified as comprehensive regulators of cold tolerance during both plumule and seedling stages. These findings lay a foundation for the fine mapping and cloning of cold tolerance genes at the plumule and seedling stages, providing valuable insights for breeding cold-tolerant rice varieties.
Quantitative Trait Loci/genetics*
;
Oryza/growth & development*
;
Seedlings/growth & development*
;
Cold Temperature
;
Chromosome Mapping
;
Gene Expression Regulation, Plant

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