DNA methylation plays important roles in regulating gene expression during development.However,little is known about the influence of DNA methylation on secondary metabolism during leaf development in the tea plant(Ca...DNA methylation plays important roles in regulating gene expression during development.However,little is known about the influence of DNA methylation on secondary metabolism during leaf development in the tea plant(Camellia sinensis).In this study,we combined the methylome,transcriptome,and metabolome to investigate the dynamic changes in DNA methylation and its potential regulatory roles in secondary metabolite biosynthesis.In this study,the level of genomic DNA methylation increased as leaf development progressed from tender to old leaf.It additionally exhibited a similar distribution across the genomic background at the two distinct developmental stages studied.Notably,integrated analysis of transcriptomic and methylomic data showed that DNA hypermethylation primarily occurred in genes of the phenylpropanoid,flavonoid,and terpenoid biosynthesis pathways.The effect of methylation on transcription of these secondary metabolite biosynthesis genes was dependent on the location of methylation(i.e.,in the promoter,gene or intergenic regions)and the sequence context(i.e.,CpG,CHG,or CHH).Changes in the content of catechins and terpenoids were consistent with the changes in gene transcription and the methylation state of structural genes,such as serine carboxypeptidase-like acyltransferases 1A(SCPL1A),leucoanthocyanidin reductase(LAR),and nerolidol synthase(NES).Our study provides valuable information for dissecting the effects of DNA methylation on regulation of genes involved in secondary metabolism during tea leaf development.展开更多
The anti-hair loss mechanism of Aquilaria sinensis leaf extract(ASE)has been studied by using metabolomics and network pharmacology.Metabolomics was utilized to comprehensively identify the active constituents of ASE,...The anti-hair loss mechanism of Aquilaria sinensis leaf extract(ASE)has been studied by using metabolomics and network pharmacology.Metabolomics was utilized to comprehensively identify the active constituents of ASE,and the network pharmacology was used to elucidate their anti-hair loss mechanism,which was verified by molecular docking technology.572 active compounds were identified from the ASE by metabolomics methods,where there are 1447 corresponding targets and 492 targets related to hair loss,totaling 88 targets.20 core active substances were identified by constructing a network between common targets and active substances,which include vanillic acid,chorionic acid,caffeic acid and apigenin.The five key targets of TNF,TP53,IL6,PPARG,and EGFR were screened out by the PPI network analysis on 88 common targets.The GO and KEGG pathway enrichment analysis showed that the inflammation,hormone balance,cell growth,proliferation,apoptosis,and oxidative stress are involved.Molecular docking studies have confirmed the high binding affinity between core active compounds and key targets.The drug similarity assessment on these core compounds suggested that they have the potential to be used as potential hair loss treatment drugs.This study elucidates the complex molecular mechanism of ASE in treating hair loss,and provides a reference for the future applications in hair care products.展开更多
Brassica napus(oilseed rape)is sensitive to boron(B)deficiency and exhibits young leaf curling in response to low-B stress at the seedling stage,which leads to reduced photosynthesis and plant growth.So far,no gene ha...Brassica napus(oilseed rape)is sensitive to boron(B)deficiency and exhibits young leaf curling in response to low-B stress at the seedling stage,which leads to reduced photosynthesis and plant growth.So far,no gene has been identified to be involved in B deficiency induced leaf curling.Our previous results showed the transcription factor BnaA1.WRKY53 might be involved in B-deficiency tolerance.However,altered BnaA1.WRKY53 expression does not influence B concentration in shoot,root and leaf cell walls,which suggests Bna A1.WRKY53 might be involved in other biological processes.Indeed,phenotypic and anatomical analyses revealed that BnaA1.WRKY53 negatively regulated the leaf curling induced by leaf epinasty by suppressing the overexpansion of palisade cells under B deficiency.Further transcriptome enrichment analysis of differentially expressed genes(DEGs)between wild-type and BnaA1.WRKY53overexpression line showed auxin response pathway was enriched.In addition,Arabidopsis DR5::GFP auxin reporter line showed B deficiency caused predominant auxin signal accumulation in the adaxial side and concomitant adaxial cell expansion,which indicated that B deficiency may induce leaf curling by altering auxin distribution.Phytohormone quantification and gene expression analysis demonstrated that BnaA1.WRKY53 prevent auxin overaccumulation in leaves by suppressing auxin biosynthetic genes under B deficiency.Furthermore,exogenous 1-naphthlcetic acid(NAA)treatment experiments revealed that high auxin could induce leaf curling and BnaA1.WRKY53 expression.Overall,these findings demonstrate that auxin and the transcription factor BnaA1.WRKY53 synergistically regulate leaf curling to maintain an optimal leaf area under B deficiency,and provide novel insights into the resistance mechanisms against B-deficiency-induced leaf curling in oilseed rape.展开更多
Palm leaf weaving is a traditional Chinese craft.People make different kinds of tools and things with palm leaves.At school,there is a palm leaf weaving club.Would you like to join?
The leaf nitrogen(N)to phosphorus(P)ratio(N:P)is a critical indicator of nutrient dynamics and ecosystem function.Investigating temporal variations in leaf N:P can provide valuable insights into how plants adapt to en...The leaf nitrogen(N)to phosphorus(P)ratio(N:P)is a critical indicator of nutrient dynamics and ecosystem function.Investigating temporal variations in leaf N:P can provide valuable insights into how plants adapt to environmental changes and nutrient availability.However,limited research has been conducted on long-term temporal leaf N:P variation over a range of temperature zones.Using long-term monitoring data from the Chinese Ecosystem Research Network(CERN),we investigated temporal changes in leaf N and P stoichiometry for 50 dominant tree species from 10 typical forest sites across temperate and subtropical regions,and identified the underlying mechanisms driving these changes.For both regions combined,leaf P concentration of the 50 dominant tree species decreased(20.6%),whereas leaf N:P increased(52.0%)from 2005 to 2020.Leaf P decreased and leaf N:P increased in 67% and 69% of the tree species,respectively.The leaf N:P increase was primarily driven by the tree species in eastern subtropical forests,where global change factors and soil nutrients explained 68% of leaf N:P variation.The P limitation exhibited by tree species in eastern subtropical forest ecosystems intensified over time,and elevated temperature and CO_(2) levels,coupled with decreased soil available P concentrations,appear to be the main factors driving long-term leaf N:P increases in these forests.Investigating long-term variations in soil nutrients together with global change factors will improve our understanding of the nutrient status of forest ecosystems in the context of global change and will support effective forest ecosystem management.展开更多
Wheat leaf rust,caused by Puccinia triticina(Pt),is one of the most devastating diseases in common wheat(Triticum aestivum L.)and can lead to heavy yield loss(Chai et al.2020).Leaf rust can result in 50%yield loss dur...Wheat leaf rust,caused by Puccinia triticina(Pt),is one of the most devastating diseases in common wheat(Triticum aestivum L.)and can lead to heavy yield loss(Chai et al.2020).Leaf rust can result in 50%yield loss during epidemic years(Huerta-Espino et al.2011;Gebrewahid et al.2020;Kolomiets et al.2021).Breeding varieties resistant to leaf rust have been recognized as the most effective and economical method to mitigate wheat losses caused by Pt.The narrow genetic basis of wheat constrains the number of cultivars resistant to leaf rust(Jin et al.2021).展开更多
Potassium(K)is a highly mobile nutrient element that continuously adjusts its demand strategy among and within cotton leaves through redistribution,indirectly leading to variations in the leaf potassium content(LKC,%)...Potassium(K)is a highly mobile nutrient element that continuously adjusts its demand strategy among and within cotton leaves through redistribution,indirectly leading to variations in the leaf potassium content(LKC,%)at different leaf positions.However,due to the interaction between light and leaf age,leaf sensitivity to this change varies at different positions,including the reflection and absorption of the spectrum.Selecting the optimal leaf position for monitoring is a crucial factor in the rapid and accurate evaluation of cotton LKC using spectral remote sensing technology.Therefore,this study proposes a comprehensive multi-leaf position estimation model based on the vertical distribution characteristics of LKC from top to bottom,aiming to achieve an accurate estimation of cotton LKC and optimize the strategy for selecting the monitored leaf position.Between 2020 and 2021,we collected hyperspectral imaging data of the main stem leaves at different positions from top to bottom(Li,i=1,2,3,...,n)during the cotton budding,flowering,and boll-setting stages.Vertical distribution characteristics,sensitivity differences,and spectral correlations of LKC at different leaf positions were investigated.Additionally,the optimal range of the dominant leaf position for monitoring was determined.Partial least squares regression(PLSR),random forest regression(RFR),support vector machine regression(SVR),and the entropy weight method(EWM)were employed to develop LKC estimation models for single-and multi-leaf positions.The results showed a vertical heterogeneous distribution of cotton LKC,with LKC initially increasing and then gradually decreasing from top to bottom;the average LKC of cotton reached its maximum value at the flowering stage.The upper leaf position demonstrated greater sensitivity to K and exhibited a stronger correlation with the spectrum.The selected dominant leaf positions for the three growth stages were L1-L5,L1-L4,and L1-L2,respectively.Based on the dominant leaf position monitoring range,the optimal single leaf position models for estimating LKC during the three growth stages were PLSR-L4,PLSR-L1,and SVR-L2,with the coefficient of determination of the validation set(R2val)being 0.786,0.580,and 0.768,and the root-mean-square error of the validation set(RMSEval)being 0.168,0.197,and 0.191,respectively.The multi-leaf position LKC estimation model was constructed by EWM with R2val being 0.887,0.728,and 0.703,and RMSEval being 0.134,0.172,and 0.209,respectively.In contrast,the newly developed multi-leaf position comprehensive estimation model yielded superior results,improving the model’s stability based on high accuracy,especially during the budding and flowering stages.These findings hold significant importance for investigating cotton LKC spectral models and selecting suitable leaf positions for field monitoring.展开更多
The leaf is a major organ for photosynthesis,and its shape plays an important role in plant development and yield determination in rice(Oryza sativa L.).In this study,an adaxial curled leaf mutant,termed curly leaf 1-...The leaf is a major organ for photosynthesis,and its shape plays an important role in plant development and yield determination in rice(Oryza sativa L.).In this study,an adaxial curled leaf mutant,termed curly leaf 1-1(cul1-1),was obtained by chemical mutagenesis.The leaf rolling index of the cul1-1 mutant was higher than that of the wild-type,which was caused by the abnormal development of bulliform cells(BCs).We cloned the CUL1 gene by map-based cloning.A nonsense mutation was present in the cul1-1 mutant,converting a tryptophan codon into a stop codon.The CUL1 gene encodes a chromodomain,helicase/ATPase and DNA-binding domain containing protein.Genes related to leaf rolling and BC development,such as ADL1,REL1 and ROC5,were activated by the cul1-1 mutation.The trimethylation of lysine 27 in histone 3(H3K27me3),but not H3K4me3,at the ADL1,REL1 and ROC5 loci,was reduced in the cul1-1 mutant.High-throughput mRNA sequencing indicated that the cul1-1 mutation caused genome-wide differential gene expression.The differentially expressed genes were classified into a few gene ontology terms and Kyoto encyclopedia of genes and genomes pathways.In the natural population,22 missense genomic variations in the CUL1 locus were identified,which composed of 7 haplotypes.A haplotype network was also built with haplotype II as the ancestor.The findings revealed that CUL1 is essential for normal leaf development and regulates this process by inhibiting the expression of genes involved in leaf rolling and BC development.展开更多
Two leaf color variants red-leaf(R-type)and common-leaf(G-type)of Euonymus sacrosancta Koidz.,were employed as experimental materials to elucidate the molecular mechanisms underlying chromatic transition.Physiological...Two leaf color variants red-leaf(R-type)and common-leaf(G-type)of Euonymus sacrosancta Koidz.,were employed as experimental materials to elucidate the molecular mechanisms underlying chromatic transition.Physiological profiling identified anthocyanins and flavo-noids as the predominant pigments responsible for the red foliar phenotype,which exhibited reduced chlorophyll and carotenoid accumulation but elevated soluble sugars and proteins.Comparative transcriptomic analysis revealed that differentially expressed genes(DEGs)between R-type and G-type were significantly enriched in flavonoid biosynthe-sis and carotenoid metabolism pathways.The up-regulation of 22 key genes of anthocyanin synthesis(e.g.,CHS,CHI,LAR,LDOX and UFGT)in R-type may lead to the phenotype of red leaves through the increase of anthocyanin accumula-tion.The downregulated expression of 13 carotenoid syn-thesis-related genes(e.g.,PSY,PDS and VDE)and 6 carot-enoid degradation genes(e.g.,ABA2,CYP707A and NCED)may lead to lower carotenoid content in R-type compared to G-type.Combined with weighted gene co-expression network analysis(WGCNA),five candidate genes(EsLAR,EsLDOX,EsPDS,EsCYP707A and EsABA2)were screened from two modules highly correlated with anthocyanin con-tent in E.sacrosancta leaves.These genes may play key regulatory roles in leaf coloration and could serve as candi-date genetic resources for leaf color improvement in E.sac-rosancta.Additionally,transcription factors such as C2H2s,C3Hs,and WRKYs were identified as potential regulators in the formation of R-type in E.sacrosancta.This study pro-vides the first systematic elucidation of the transcriptional regulatory network governing red-leaf formation in E.sac-rosancta,establishing a critical theoretical foundation for molecular breeding in ornamental plants.展开更多
Rapid urbanization has contributed to global increases in air pollution derived from urban areas.Unlike natural forests,urban forests are exposed to higher concentrations of airborne pollutants due to the strong urban...Rapid urbanization has contributed to global increases in air pollution derived from urban areas.Unlike natural forests,urban forests are exposed to higher concentrations of airborne pollutants due to the strong urban-suburban-rural pollutant emission gradients.However,there remains a pressing lack of available information pertaining to the urban air pollutionrelated effects on the leaf economics spectrum,anatomical,ultrastructural,and stomatal traits of tree species along an urban-rural gradient.Here,the degree to which urban air pollution impacts the adaption of greening tree species and associated service functions was assessed by sampling five common tree species(Acer pictum,Fraxinus chinensis,Koelreuteria paniculata,Salix babylonica,Sophora japonica)along urban-rural-natural forests in the Beijing metropolitan region of China.These analyses revealed a significant reduction in leaf mass per unit area(-13.4%),leaf thickness(-16.7%),and stomatal area(-27.5%)with increasing proximity to areas of greater air pollution that coincide with significant increases in leaf tissue density(+12.6%),leaf nitrogen content(+10.1%),relative chlorophyll content(+2.7%),and stomatal density(+11.9%).Higher air pollution levels were associated with organelle changes including gradual disintegration of chloroplasts,larger intercellular spaces and apparent starch and plastoglobuli deposition.Air pollutionwas conducive to the strengthening of the trade-off potential and adaptation strategies of trees in urban ecosystems,which are associated with trees with a rapid investment return strategy associated with thick leaves and strong photosynthetic capacity.These results provide strong empirical evidence of the profound air pollution-induced changes in leaf functional traits and adaption ability of urban forest tree species.展开更多
Sunflower leaf photosynthesis strongly depends on the leaf position in the plant stem conditioning,which directly affects other physiological processes.Therefore,a study of the leaf’s physiological status regarding t...Sunflower leaf photosynthesis strongly depends on the leaf position in the plant stem conditioning,which directly affects other physiological processes.Therefore,a study of the leaf’s physiological status regarding the leaf position in the stem was performed on sunflowers in the flowering stage.Eight differently positioned leaves were investigated,starting with the youngest leaf on the top of the stem to the leaves of the stem bottom,assigned as the oldest senescent leaves.According to chlorophyll fluorescence(ChlF)parameters connected to photosystem II(PSII)processes,significant changes in PSII functioning occurred only in the senescent leaves,while photosystem I(PSI)describing parameters showed a linear decrease with leaf age,i.e.,position on the stem.The antioxidative status of the leaves was dynamic,as stress indicators(lipid peroxidation and hydrogen peroxide content)fluctuated regarding leaf position on the stem,but no link was found between the activities of antioxidative enzymes and oxidative stress indicators.Linear decrease trend of secondary metabolites(mainly phenolic compounds)correlated with antioxidant activity,except for some phenolic acids(caffeic and ferulic acid),which increased in senescent leaves.The most changes in the physiological status of the leaves were confirmed in senescent leaves,which stand out the importance of younger leaves in maintaining the plant’s vitality after flowering,which is the most important for sunflower yield.展开更多
Flag leaf angle(FLANG)is one of the key traits in wheat breeding due to its impact on plant architecture,light interception,and yield potential.An image-based method of measuring FLANG in wheat would reduce the labor ...Flag leaf angle(FLANG)is one of the key traits in wheat breeding due to its impact on plant architecture,light interception,and yield potential.An image-based method of measuring FLANG in wheat would reduce the labor and error of manual measurement of this trait.We describe a method for acquiring in-field FLANG images and a lightweight deep learning model named LeafPoseNet that incorporates a spatial attention mechanism for FLANG estimation.In a test dataset with wheat varieties exhibiting diverse FLANG,LeafPoseNet achieved high accuracy in predicting the FLANG,with a mean absolute error(MAE)of 1.75°,a root mean square error(RMSE)of 2.17°,and a coefficient of determination(R2)of 0.998,significantly outperforming established models such as YOLO12x-pose,YOLO11x-pose,HigherHRNet,Lightweight-OpenPose,and LitePose.We performed phenotyping and genome-wide association study to identify the genomic regions associated with FLANG in a panel of 221 diverse bread wheat genotypes,and identified 10 quantitative trait loci.Among them,qFLANG2B.2 was found to harbor a potential causal gene,TraesCS2B01G313700,which may regulate FLANG formation by modulating brassinosteroid levels.This method provides a low-cost,high-accuracy solution for in-field phenotyping of wheat FLANG,facilitating both wheat FLANG genetic studies and ideal plant type breeding.展开更多
Hybridization remains an important method for breeding new poplar varieties.It results in significant variation in leaf phenotype among parents and offspring,and among offspring themselves.This study aimed to investig...Hybridization remains an important method for breeding new poplar varieties.It results in significant variation in leaf phenotype among parents and offspring,and among offspring themselves.This study aimed to investigate whether leaf shape variations were similar in offspring produced from reciprocal crosses.Specifically,two hybrid combinations were produced:the direct cross with Populus ussuriensis as the maternal parent and P.simonii×P.nigra as the paternal parent(HY53),and the reciprocal cross with P.simonii×P.nigra as the maternal parent and P.ussuriensis as the paternal parent(HY268).Using 3-month-old rooted cuttings from 40 clones(36 F1 hybrids and their parents)growing in a greenhouse,we measured and analyzed 14 leaf morphological traits to assess genetic variation and heterosis.The results showed HY53 clones generally exhibited greater average height than HY268 clones.Leaf phenotypes differed between the two hybrid combinations,with significant differences observed among parents and offspring for almost all traits,as revealed by analysis of variance(ANOVA).The phenotypic coefficient of variation was higher in HY268 clones.Additionally,leaf traits demonstrated high repeatability.Notably,some hybrid offspring exhibited positive or negative mid-parent heterosis,as well as over-parent heterosis for certain leaf phenotypes.The systematic cluster analysis further indicated distinct separation among HY268 clones.This research provides valuable materials for poplar breeding and offers insights into hybrid vigor in wood plants.The findings highlight the importance of reciprocal crossing in influencing leaf phenotype variation and heterosis,offering practical insights for future breeding strategies.展开更多
Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the p...Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below.展开更多
Planting density is a major limiting factor for maize yield,and breeding for density tolerance has become an urgent issue.The leaf structure of the maize ear leaf is the main factor that restricts planting density and...Planting density is a major limiting factor for maize yield,and breeding for density tolerance has become an urgent issue.The leaf structure of the maize ear leaf is the main factor that restricts planting density and yield components.In this study,a natural population of 201 maize inbred lines was used for genome-wide association analysis,which identified nine SNPs on chromosomes 2,5,8,9,and 10 that were significantly associated with ear leaf type structure.Further verification through qRT-PCR confirmed the association of five candidate genes with these SNPs,with the Zm00001d008651 gene showing significant differential expression in the compact and flat maize inbred lines.Enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes(KEGG)and Gene Ontology(GO)databasessuggested that this gene is involved in the glycolysis process.An analysis of the basic properties of this gene revealed that it encodes a stable,basic protein consisting of 593 amino acids with some hydrophobic properties.The promoter region contains stress and hormone(abscisic acid(ABA))related elements.The mutant of this gene increased the first ear leaf angle(eLA)and leaf angle of the first leaf below the first ear(bLA)by 4.96 and 0.97°,respectively,compared with normal inbred lines.Overall,this research sheds light on the regulatory mechanism of ear and leaf structures that influence density tolerance and provides solid foundational work for the development of new varieties.展开更多
This study was carried out to assess plasticity to drought of 30 adult fig cultivars,based on a screening of leaf structural and functional traits under sustained deficit irrigation,corresponding to 60%of crop evapotr...This study was carried out to assess plasticity to drought of 30 adult fig cultivars,based on a screening of leaf structural and functional traits under sustained deficit irrigation,corresponding to 60%of crop evapotranspiration.All trees,three per cultivar,are planted in an ex-situ collection in Sais plain,northern Morocco.The measurements concerned leaf area,blade thickness,trichomes density,trichome hair length,stomatal density,stomatal dimensions,stomatal area index,chlorophyll concentration index,relative water content,stomatal conductance,leaf temperature,water loss in detached leaves,cuticular wax content,proline content,total phenolic compounds,and total soluble sugars.The ranking of cultivars regarding drought tolerance was established based on a two-level clustering approach,primarily relying on chlorophyll concentration index and secondarily on water status traits.Results showed significant genotypic variations for all measured traits,except phenolic compounds content.Correlations between structural and functional traits have pinpointed blade thickness and trichome hair length as the key indicators of fig drought tolerance,owing to their involvement in maintaining chlorophyll content under water stress conditions.The extent of the variations shows that fig leaf is endowed with a wide structural and functional diversity,which can give to the species potential for resilience to various environmental stresses,including drought.Among the cultivars assessed,two exotic varieties,“Kadota”and“Royal Blanck”,as well as four local cultivars,namely,“Ferqouch Jmel”,“El Qoti Labied”,“Hamra”and“Fassi”showed the highest drought plasticity level.展开更多
A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting....A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting. Furthermore, it was observed that the earlier being sown, the greater the rate of premature bolting when being sown prior to middle August. The rate of premature bolting observed in seedlings sown on August 8 was recorded at 35.6%. It was noted that as the age of the seedlings increased, the rate of premature bolting correspondingly increased. There were notable differences in the tolerance of various cultivars to elevated temperatures and prolonged sunlight exposure. For instance, cultivars such as Zhangjie 1 and Sichuan Shaguodi, which exhibit greater heat resistance, did not demonstrate premature bolting when sown in early August. The prolonged exposure to elevated temperatures, drought conditions, and extended periods of sunlight during the seedling stage of Huarong large leaf mustard, coupled with delayed irrigation and transplantation, contributed to the occurrence of premature bolting. The Huarong large leaf mustard, when been sown from late August to early September and transplanted at the appropriate time, exhibited normal growth and development, with no instances of premature bolting observed. It is advisable to select heat-resistant varieties, such as Zhangjie 1, prior to middle August. Huarong large leaf mustard should be sown in early to middle September. Additionally, it is essential to ensure centralized production and timely release of seeds, prompt transplantation and harvesting, and enhance the management of pests and diseases.展开更多
Background:The effects of perilla leaf oil on the antibacterial activity,biofilm formation,and group sensing related genes of Salmonella dysentery in chickens were investigated.Perilla leaf oil was compared with the a...Background:The effects of perilla leaf oil on the antibacterial activity,biofilm formation,and group sensing related genes of Salmonella dysentery in chickens were investigated.Perilla leaf oil was compared with the antibiotic gentamycin hydrochloride,which is commonly used in the chicken industry,to provide experimental data and theoretical basis for the further development of perilla leaf oil as a new type of antimicrobial drug to replace feed antibiotics.Methods:The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of perilla leaf oil and the antibiotic aureomycin hydrochloride against three clinical isolates of Salmonella typhimurium were determined by microbial broth dilution,and SP-2 was screened out from them.The dynamic bactericidal effect of perilla leaf oil and aureomycin hydrochloride on SP-2 was obtained by the viable bacteria counting method and the time-bactericidal curves.The successful establishment of biological periplasm and the corresponding times of its various growth stages of adhesion,aggregation,and maturation were determined by cell counting kit-8(CCK-8)reagent and scanning electron microscopy(SEM).The effects of different concentrations of perilla leaf oil on biofilm at different stages were investigated by CCK-8 method and semi-quantitative adhesion method of crystalline violet,and the changes in microstructure and morphology of biofilm at different stages under the effect of drugs were observed by SEM.The effect of perilla leaf oil on the expression of genes related to the formation of the population sensing system(luxS and sdiA)in the test strain SP-2 was detected by qRT-PCR.Results:The MIC value of perilla leaf oil on SP-2 was 2.000±0.000 mg/mL.Perilla leaf oil and gentamycin hydrochloride could effectively inhibit and kill SP-2 in a planktonic state,and delay the entry of bacteria into the logarithmic growth period.6 h,24 h,and 48 h were chosen as the time points for the drug intervention in the initial adhesion,aggregation,and maturation stages of the biofilm of SP-2.1 mg/mL perilla leaf oil was significantly better than the same concentration of gentamycin hydrochloride in removing the total amount of biofilm of SP-2 at all growth stages(P<0.05).The inhibitory effect of 4 mg/mL perilla leaf oil on the bacterial metabolic activity in SP-2 biofilm at the mature stage was significantly better than that of the same concentration of gentamycin hydrochloride(P<0.01).For SP-2 biofilm at all stages of growth,different concentrations of perilla leaf oil significantly down-regulated the expression of luxS and sdiA genes(P<0.05),interfered with the group sensing system of SP-2,and inhibited the formation of its biofilm.Conclusion:The perilla leaf oil has a good antibacterial activity and biofilm inhibition effect on SP-2 of S.Pullorum at different growth stages.展开更多
基金supported by the Natural Science Foundation of Guangdong Province(Grant Nos.2022A1515111141 and 2023A1515010786)。
文摘DNA methylation plays important roles in regulating gene expression during development.However,little is known about the influence of DNA methylation on secondary metabolism during leaf development in the tea plant(Camellia sinensis).In this study,we combined the methylome,transcriptome,and metabolome to investigate the dynamic changes in DNA methylation and its potential regulatory roles in secondary metabolite biosynthesis.In this study,the level of genomic DNA methylation increased as leaf development progressed from tender to old leaf.It additionally exhibited a similar distribution across the genomic background at the two distinct developmental stages studied.Notably,integrated analysis of transcriptomic and methylomic data showed that DNA hypermethylation primarily occurred in genes of the phenylpropanoid,flavonoid,and terpenoid biosynthesis pathways.The effect of methylation on transcription of these secondary metabolite biosynthesis genes was dependent on the location of methylation(i.e.,in the promoter,gene or intergenic regions)and the sequence context(i.e.,CpG,CHG,or CHH).Changes in the content of catechins and terpenoids were consistent with the changes in gene transcription and the methylation state of structural genes,such as serine carboxypeptidase-like acyltransferases 1A(SCPL1A),leucoanthocyanidin reductase(LAR),and nerolidol synthase(NES).Our study provides valuable information for dissecting the effects of DNA methylation on regulation of genes involved in secondary metabolism during tea leaf development.
文摘The anti-hair loss mechanism of Aquilaria sinensis leaf extract(ASE)has been studied by using metabolomics and network pharmacology.Metabolomics was utilized to comprehensively identify the active constituents of ASE,and the network pharmacology was used to elucidate their anti-hair loss mechanism,which was verified by molecular docking technology.572 active compounds were identified from the ASE by metabolomics methods,where there are 1447 corresponding targets and 492 targets related to hair loss,totaling 88 targets.20 core active substances were identified by constructing a network between common targets and active substances,which include vanillic acid,chorionic acid,caffeic acid and apigenin.The five key targets of TNF,TP53,IL6,PPARG,and EGFR were screened out by the PPI network analysis on 88 common targets.The GO and KEGG pathway enrichment analysis showed that the inflammation,hormone balance,cell growth,proliferation,apoptosis,and oxidative stress are involved.Molecular docking studies have confirmed the high binding affinity between core active compounds and key targets.The drug similarity assessment on these core compounds suggested that they have the potential to be used as potential hair loss treatment drugs.This study elucidates the complex molecular mechanism of ASE in treating hair loss,and provides a reference for the future applications in hair care products.
基金supported by the National Natural Science Foundation of China(32002122,32372805)。
文摘Brassica napus(oilseed rape)is sensitive to boron(B)deficiency and exhibits young leaf curling in response to low-B stress at the seedling stage,which leads to reduced photosynthesis and plant growth.So far,no gene has been identified to be involved in B deficiency induced leaf curling.Our previous results showed the transcription factor BnaA1.WRKY53 might be involved in B-deficiency tolerance.However,altered BnaA1.WRKY53 expression does not influence B concentration in shoot,root and leaf cell walls,which suggests Bna A1.WRKY53 might be involved in other biological processes.Indeed,phenotypic and anatomical analyses revealed that BnaA1.WRKY53 negatively regulated the leaf curling induced by leaf epinasty by suppressing the overexpansion of palisade cells under B deficiency.Further transcriptome enrichment analysis of differentially expressed genes(DEGs)between wild-type and BnaA1.WRKY53overexpression line showed auxin response pathway was enriched.In addition,Arabidopsis DR5::GFP auxin reporter line showed B deficiency caused predominant auxin signal accumulation in the adaxial side and concomitant adaxial cell expansion,which indicated that B deficiency may induce leaf curling by altering auxin distribution.Phytohormone quantification and gene expression analysis demonstrated that BnaA1.WRKY53 prevent auxin overaccumulation in leaves by suppressing auxin biosynthetic genes under B deficiency.Furthermore,exogenous 1-naphthlcetic acid(NAA)treatment experiments revealed that high auxin could induce leaf curling and BnaA1.WRKY53 expression.Overall,these findings demonstrate that auxin and the transcription factor BnaA1.WRKY53 synergistically regulate leaf curling to maintain an optimal leaf area under B deficiency,and provide novel insights into the resistance mechanisms against B-deficiency-induced leaf curling in oilseed rape.
文摘Palm leaf weaving is a traditional Chinese craft.People make different kinds of tools and things with palm leaves.At school,there is a palm leaf weaving club.Would you like to join?
基金supported by the National Natural Science Foundation of China(No.42030509)the Special Project on National Science and Technology Basic Resources Investigation of China(No.2021FY100705).
文摘The leaf nitrogen(N)to phosphorus(P)ratio(N:P)is a critical indicator of nutrient dynamics and ecosystem function.Investigating temporal variations in leaf N:P can provide valuable insights into how plants adapt to environmental changes and nutrient availability.However,limited research has been conducted on long-term temporal leaf N:P variation over a range of temperature zones.Using long-term monitoring data from the Chinese Ecosystem Research Network(CERN),we investigated temporal changes in leaf N and P stoichiometry for 50 dominant tree species from 10 typical forest sites across temperate and subtropical regions,and identified the underlying mechanisms driving these changes.For both regions combined,leaf P concentration of the 50 dominant tree species decreased(20.6%),whereas leaf N:P increased(52.0%)from 2005 to 2020.Leaf P decreased and leaf N:P increased in 67% and 69% of the tree species,respectively.The leaf N:P increase was primarily driven by the tree species in eastern subtropical forests,where global change factors and soil nutrients explained 68% of leaf N:P variation.The P limitation exhibited by tree species in eastern subtropical forest ecosystems intensified over time,and elevated temperature and CO_(2) levels,coupled with decreased soil available P concentrations,appear to be the main factors driving long-term leaf N:P increases in these forests.Investigating long-term variations in soil nutrients together with global change factors will improve our understanding of the nutrient status of forest ecosystems in the context of global change and will support effective forest ecosystem management.
基金funded by the National Natural Science Foundation of China(32272083)。
文摘Wheat leaf rust,caused by Puccinia triticina(Pt),is one of the most devastating diseases in common wheat(Triticum aestivum L.)and can lead to heavy yield loss(Chai et al.2020).Leaf rust can result in 50%yield loss during epidemic years(Huerta-Espino et al.2011;Gebrewahid et al.2020;Kolomiets et al.2021).Breeding varieties resistant to leaf rust have been recognized as the most effective and economical method to mitigate wheat losses caused by Pt.The narrow genetic basis of wheat constrains the number of cultivars resistant to leaf rust(Jin et al.2021).
基金supported by the Corps Leading Talents Program,China(2023YZ01)the Tianshan Talent Training Program,China(2023TS05)the Crop Smart Production Innovation Team,China(2023TD01).
文摘Potassium(K)is a highly mobile nutrient element that continuously adjusts its demand strategy among and within cotton leaves through redistribution,indirectly leading to variations in the leaf potassium content(LKC,%)at different leaf positions.However,due to the interaction between light and leaf age,leaf sensitivity to this change varies at different positions,including the reflection and absorption of the spectrum.Selecting the optimal leaf position for monitoring is a crucial factor in the rapid and accurate evaluation of cotton LKC using spectral remote sensing technology.Therefore,this study proposes a comprehensive multi-leaf position estimation model based on the vertical distribution characteristics of LKC from top to bottom,aiming to achieve an accurate estimation of cotton LKC and optimize the strategy for selecting the monitored leaf position.Between 2020 and 2021,we collected hyperspectral imaging data of the main stem leaves at different positions from top to bottom(Li,i=1,2,3,...,n)during the cotton budding,flowering,and boll-setting stages.Vertical distribution characteristics,sensitivity differences,and spectral correlations of LKC at different leaf positions were investigated.Additionally,the optimal range of the dominant leaf position for monitoring was determined.Partial least squares regression(PLSR),random forest regression(RFR),support vector machine regression(SVR),and the entropy weight method(EWM)were employed to develop LKC estimation models for single-and multi-leaf positions.The results showed a vertical heterogeneous distribution of cotton LKC,with LKC initially increasing and then gradually decreasing from top to bottom;the average LKC of cotton reached its maximum value at the flowering stage.The upper leaf position demonstrated greater sensitivity to K and exhibited a stronger correlation with the spectrum.The selected dominant leaf positions for the three growth stages were L1-L5,L1-L4,and L1-L2,respectively.Based on the dominant leaf position monitoring range,the optimal single leaf position models for estimating LKC during the three growth stages were PLSR-L4,PLSR-L1,and SVR-L2,with the coefficient of determination of the validation set(R2val)being 0.786,0.580,and 0.768,and the root-mean-square error of the validation set(RMSEval)being 0.168,0.197,and 0.191,respectively.The multi-leaf position LKC estimation model was constructed by EWM with R2val being 0.887,0.728,and 0.703,and RMSEval being 0.134,0.172,and 0.209,respectively.In contrast,the newly developed multi-leaf position comprehensive estimation model yielded superior results,improving the model’s stability based on high accuracy,especially during the budding and flowering stages.These findings hold significant importance for investigating cotton LKC spectral models and selecting suitable leaf positions for field monitoring.
基金supported by the National Natural Science Foundation of China(32070642 and 31371222 to Dr.Xiaoxue Wang)the National Key Research and Development Program from the Ministry of Science and Technology of China(2016YFD0100406 and 2017YFD0300107 to Dr.Xiaoxue Wang)the Science and Technology Department of Liaoning province(2022JH6/100100039 to Dr.Xiaoxue Wang)。
文摘The leaf is a major organ for photosynthesis,and its shape plays an important role in plant development and yield determination in rice(Oryza sativa L.).In this study,an adaxial curled leaf mutant,termed curly leaf 1-1(cul1-1),was obtained by chemical mutagenesis.The leaf rolling index of the cul1-1 mutant was higher than that of the wild-type,which was caused by the abnormal development of bulliform cells(BCs).We cloned the CUL1 gene by map-based cloning.A nonsense mutation was present in the cul1-1 mutant,converting a tryptophan codon into a stop codon.The CUL1 gene encodes a chromodomain,helicase/ATPase and DNA-binding domain containing protein.Genes related to leaf rolling and BC development,such as ADL1,REL1 and ROC5,were activated by the cul1-1 mutation.The trimethylation of lysine 27 in histone 3(H3K27me3),but not H3K4me3,at the ADL1,REL1 and ROC5 loci,was reduced in the cul1-1 mutant.High-throughput mRNA sequencing indicated that the cul1-1 mutation caused genome-wide differential gene expression.The differentially expressed genes were classified into a few gene ontology terms and Kyoto encyclopedia of genes and genomes pathways.In the natural population,22 missense genomic variations in the CUL1 locus were identified,which composed of 7 haplotypes.A haplotype network was also built with haplotype II as the ancestor.The findings revealed that CUL1 is essential for normal leaf development and regulates this process by inhibiting the expression of genes involved in leaf rolling and BC development.
基金supported by the National Natural Science Foundation of China(No.32171738)the National Key Research and Development Program of China(No.2021YFD2200304)the Fundamental Research Funds for the Central Universities(No.2572022DQ08).
文摘Two leaf color variants red-leaf(R-type)and common-leaf(G-type)of Euonymus sacrosancta Koidz.,were employed as experimental materials to elucidate the molecular mechanisms underlying chromatic transition.Physiological profiling identified anthocyanins and flavo-noids as the predominant pigments responsible for the red foliar phenotype,which exhibited reduced chlorophyll and carotenoid accumulation but elevated soluble sugars and proteins.Comparative transcriptomic analysis revealed that differentially expressed genes(DEGs)between R-type and G-type were significantly enriched in flavonoid biosynthe-sis and carotenoid metabolism pathways.The up-regulation of 22 key genes of anthocyanin synthesis(e.g.,CHS,CHI,LAR,LDOX and UFGT)in R-type may lead to the phenotype of red leaves through the increase of anthocyanin accumula-tion.The downregulated expression of 13 carotenoid syn-thesis-related genes(e.g.,PSY,PDS and VDE)and 6 carot-enoid degradation genes(e.g.,ABA2,CYP707A and NCED)may lead to lower carotenoid content in R-type compared to G-type.Combined with weighted gene co-expression network analysis(WGCNA),five candidate genes(EsLAR,EsLDOX,EsPDS,EsCYP707A and EsABA2)were screened from two modules highly correlated with anthocyanin con-tent in E.sacrosancta leaves.These genes may play key regulatory roles in leaf coloration and could serve as candi-date genetic resources for leaf color improvement in E.sac-rosancta.Additionally,transcription factors such as C2H2s,C3Hs,and WRKYs were identified as potential regulators in the formation of R-type in E.sacrosancta.This study pro-vides the first systematic elucidation of the transcriptional regulatory network governing red-leaf formation in E.sac-rosancta,establishing a critical theoretical foundation for molecular breeding in ornamental plants.
基金supported by the National Natural Science Foundation of China(No.32271673)5·5 Engineering Research&Innovation Team Project of Beijing Forestry University(No.BLRC2023B06).
文摘Rapid urbanization has contributed to global increases in air pollution derived from urban areas.Unlike natural forests,urban forests are exposed to higher concentrations of airborne pollutants due to the strong urban-suburban-rural pollutant emission gradients.However,there remains a pressing lack of available information pertaining to the urban air pollutionrelated effects on the leaf economics spectrum,anatomical,ultrastructural,and stomatal traits of tree species along an urban-rural gradient.Here,the degree to which urban air pollution impacts the adaption of greening tree species and associated service functions was assessed by sampling five common tree species(Acer pictum,Fraxinus chinensis,Koelreuteria paniculata,Salix babylonica,Sophora japonica)along urban-rural-natural forests in the Beijing metropolitan region of China.These analyses revealed a significant reduction in leaf mass per unit area(-13.4%),leaf thickness(-16.7%),and stomatal area(-27.5%)with increasing proximity to areas of greater air pollution that coincide with significant increases in leaf tissue density(+12.6%),leaf nitrogen content(+10.1%),relative chlorophyll content(+2.7%),and stomatal density(+11.9%).Higher air pollution levels were associated with organelle changes including gradual disintegration of chloroplasts,larger intercellular spaces and apparent starch and plastoglobuli deposition.Air pollutionwas conducive to the strengthening of the trade-off potential and adaptation strategies of trees in urban ecosystems,which are associated with trees with a rapid investment return strategy associated with thick leaves and strong photosynthetic capacity.These results provide strong empirical evidence of the profound air pollution-induced changes in leaf functional traits and adaption ability of urban forest tree species.
文摘Sunflower leaf photosynthesis strongly depends on the leaf position in the plant stem conditioning,which directly affects other physiological processes.Therefore,a study of the leaf’s physiological status regarding the leaf position in the stem was performed on sunflowers in the flowering stage.Eight differently positioned leaves were investigated,starting with the youngest leaf on the top of the stem to the leaves of the stem bottom,assigned as the oldest senescent leaves.According to chlorophyll fluorescence(ChlF)parameters connected to photosystem II(PSII)processes,significant changes in PSII functioning occurred only in the senescent leaves,while photosystem I(PSI)describing parameters showed a linear decrease with leaf age,i.e.,position on the stem.The antioxidative status of the leaves was dynamic,as stress indicators(lipid peroxidation and hydrogen peroxide content)fluctuated regarding leaf position on the stem,but no link was found between the activities of antioxidative enzymes and oxidative stress indicators.Linear decrease trend of secondary metabolites(mainly phenolic compounds)correlated with antioxidant activity,except for some phenolic acids(caffeic and ferulic acid),which increased in senescent leaves.The most changes in the physiological status of the leaves were confirmed in senescent leaves,which stand out the importance of younger leaves in maintaining the plant’s vitality after flowering,which is the most important for sunflower yield.
基金supported by the Biological Breeding-National Science and Technology Major Project(2023ZD04076)the National Key Research and Development Program of China(2023YFF1000100)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0450000).
文摘Flag leaf angle(FLANG)is one of the key traits in wheat breeding due to its impact on plant architecture,light interception,and yield potential.An image-based method of measuring FLANG in wheat would reduce the labor and error of manual measurement of this trait.We describe a method for acquiring in-field FLANG images and a lightweight deep learning model named LeafPoseNet that incorporates a spatial attention mechanism for FLANG estimation.In a test dataset with wheat varieties exhibiting diverse FLANG,LeafPoseNet achieved high accuracy in predicting the FLANG,with a mean absolute error(MAE)of 1.75°,a root mean square error(RMSE)of 2.17°,and a coefficient of determination(R2)of 0.998,significantly outperforming established models such as YOLO12x-pose,YOLO11x-pose,HigherHRNet,Lightweight-OpenPose,and LitePose.We performed phenotyping and genome-wide association study to identify the genomic regions associated with FLANG in a panel of 221 diverse bread wheat genotypes,and identified 10 quantitative trait loci.Among them,qFLANG2B.2 was found to harbor a potential causal gene,TraesCS2B01G313700,which may regulate FLANG formation by modulating brassinosteroid levels.This method provides a low-cost,high-accuracy solution for in-field phenotyping of wheat FLANG,facilitating both wheat FLANG genetic studies and ideal plant type breeding.
基金supported by“National Key R&D Program of China(2021YFD2200203)”“the Fundamental Research Funds for the Central Universities(No.2572022AW02 and No.2572023CT19)”。
文摘Hybridization remains an important method for breeding new poplar varieties.It results in significant variation in leaf phenotype among parents and offspring,and among offspring themselves.This study aimed to investigate whether leaf shape variations were similar in offspring produced from reciprocal crosses.Specifically,two hybrid combinations were produced:the direct cross with Populus ussuriensis as the maternal parent and P.simonii×P.nigra as the paternal parent(HY53),and the reciprocal cross with P.simonii×P.nigra as the maternal parent and P.ussuriensis as the paternal parent(HY268).Using 3-month-old rooted cuttings from 40 clones(36 F1 hybrids and their parents)growing in a greenhouse,we measured and analyzed 14 leaf morphological traits to assess genetic variation and heterosis.The results showed HY53 clones generally exhibited greater average height than HY268 clones.Leaf phenotypes differed between the two hybrid combinations,with significant differences observed among parents and offspring for almost all traits,as revealed by analysis of variance(ANOVA).The phenotypic coefficient of variation was higher in HY268 clones.Additionally,leaf traits demonstrated high repeatability.Notably,some hybrid offspring exhibited positive or negative mid-parent heterosis,as well as over-parent heterosis for certain leaf phenotypes.The systematic cluster analysis further indicated distinct separation among HY268 clones.This research provides valuable materials for poplar breeding and offers insights into hybrid vigor in wood plants.The findings highlight the importance of reciprocal crossing in influencing leaf phenotype variation and heterosis,offering practical insights for future breeding strategies.
文摘Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below.
基金supported by the Key Research and Development Project of Heilongjiang Province,China(2022ZX02B01)。
文摘Planting density is a major limiting factor for maize yield,and breeding for density tolerance has become an urgent issue.The leaf structure of the maize ear leaf is the main factor that restricts planting density and yield components.In this study,a natural population of 201 maize inbred lines was used for genome-wide association analysis,which identified nine SNPs on chromosomes 2,5,8,9,and 10 that were significantly associated with ear leaf type structure.Further verification through qRT-PCR confirmed the association of five candidate genes with these SNPs,with the Zm00001d008651 gene showing significant differential expression in the compact and flat maize inbred lines.Enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes(KEGG)and Gene Ontology(GO)databasessuggested that this gene is involved in the glycolysis process.An analysis of the basic properties of this gene revealed that it encodes a stable,basic protein consisting of 593 amino acids with some hydrophobic properties.The promoter region contains stress and hormone(abscisic acid(ABA))related elements.The mutant of this gene increased the first ear leaf angle(eLA)and leaf angle of the first leaf below the first ear(bLA)by 4.96 and 0.97°,respectively,compared with normal inbred lines.Overall,this research sheds light on the regulatory mechanism of ear and leaf structures that influence density tolerance and provides solid foundational work for the development of new varieties.
文摘This study was carried out to assess plasticity to drought of 30 adult fig cultivars,based on a screening of leaf structural and functional traits under sustained deficit irrigation,corresponding to 60%of crop evapotranspiration.All trees,three per cultivar,are planted in an ex-situ collection in Sais plain,northern Morocco.The measurements concerned leaf area,blade thickness,trichomes density,trichome hair length,stomatal density,stomatal dimensions,stomatal area index,chlorophyll concentration index,relative water content,stomatal conductance,leaf temperature,water loss in detached leaves,cuticular wax content,proline content,total phenolic compounds,and total soluble sugars.The ranking of cultivars regarding drought tolerance was established based on a two-level clustering approach,primarily relying on chlorophyll concentration index and secondarily on water status traits.Results showed significant genotypic variations for all measured traits,except phenolic compounds content.Correlations between structural and functional traits have pinpointed blade thickness and trichome hair length as the key indicators of fig drought tolerance,owing to their involvement in maintaining chlorophyll content under water stress conditions.The extent of the variations shows that fig leaf is endowed with a wide structural and functional diversity,which can give to the species potential for resilience to various environmental stresses,including drought.Among the cultivars assessed,two exotic varieties,“Kadota”and“Royal Blanck”,as well as four local cultivars,namely,“Ferqouch Jmel”,“El Qoti Labied”,“Hamra”and“Fassi”showed the highest drought plasticity level.
基金Supported by Key R&D Projects of Hunan Provincial Department of Science and Technology"Study on Key Modern Processing Techniques and Product Development of Huarong Mustard"(2023NK2039).
文摘A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting. Furthermore, it was observed that the earlier being sown, the greater the rate of premature bolting when being sown prior to middle August. The rate of premature bolting observed in seedlings sown on August 8 was recorded at 35.6%. It was noted that as the age of the seedlings increased, the rate of premature bolting correspondingly increased. There were notable differences in the tolerance of various cultivars to elevated temperatures and prolonged sunlight exposure. For instance, cultivars such as Zhangjie 1 and Sichuan Shaguodi, which exhibit greater heat resistance, did not demonstrate premature bolting when sown in early August. The prolonged exposure to elevated temperatures, drought conditions, and extended periods of sunlight during the seedling stage of Huarong large leaf mustard, coupled with delayed irrigation and transplantation, contributed to the occurrence of premature bolting. The Huarong large leaf mustard, when been sown from late August to early September and transplanted at the appropriate time, exhibited normal growth and development, with no instances of premature bolting observed. It is advisable to select heat-resistant varieties, such as Zhangjie 1, prior to middle August. Huarong large leaf mustard should be sown in early to middle September. Additionally, it is essential to ensure centralized production and timely release of seeds, prompt transplantation and harvesting, and enhance the management of pests and diseases.
文摘Background:The effects of perilla leaf oil on the antibacterial activity,biofilm formation,and group sensing related genes of Salmonella dysentery in chickens were investigated.Perilla leaf oil was compared with the antibiotic gentamycin hydrochloride,which is commonly used in the chicken industry,to provide experimental data and theoretical basis for the further development of perilla leaf oil as a new type of antimicrobial drug to replace feed antibiotics.Methods:The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of perilla leaf oil and the antibiotic aureomycin hydrochloride against three clinical isolates of Salmonella typhimurium were determined by microbial broth dilution,and SP-2 was screened out from them.The dynamic bactericidal effect of perilla leaf oil and aureomycin hydrochloride on SP-2 was obtained by the viable bacteria counting method and the time-bactericidal curves.The successful establishment of biological periplasm and the corresponding times of its various growth stages of adhesion,aggregation,and maturation were determined by cell counting kit-8(CCK-8)reagent and scanning electron microscopy(SEM).The effects of different concentrations of perilla leaf oil on biofilm at different stages were investigated by CCK-8 method and semi-quantitative adhesion method of crystalline violet,and the changes in microstructure and morphology of biofilm at different stages under the effect of drugs were observed by SEM.The effect of perilla leaf oil on the expression of genes related to the formation of the population sensing system(luxS and sdiA)in the test strain SP-2 was detected by qRT-PCR.Results:The MIC value of perilla leaf oil on SP-2 was 2.000±0.000 mg/mL.Perilla leaf oil and gentamycin hydrochloride could effectively inhibit and kill SP-2 in a planktonic state,and delay the entry of bacteria into the logarithmic growth period.6 h,24 h,and 48 h were chosen as the time points for the drug intervention in the initial adhesion,aggregation,and maturation stages of the biofilm of SP-2.1 mg/mL perilla leaf oil was significantly better than the same concentration of gentamycin hydrochloride in removing the total amount of biofilm of SP-2 at all growth stages(P<0.05).The inhibitory effect of 4 mg/mL perilla leaf oil on the bacterial metabolic activity in SP-2 biofilm at the mature stage was significantly better than that of the same concentration of gentamycin hydrochloride(P<0.01).For SP-2 biofilm at all stages of growth,different concentrations of perilla leaf oil significantly down-regulated the expression of luxS and sdiA genes(P<0.05),interfered with the group sensing system of SP-2,and inhibited the formation of its biofilm.Conclusion:The perilla leaf oil has a good antibacterial activity and biofilm inhibition effect on SP-2 of S.Pullorum at different growth stages.
