Chitin is an abundant natural biopolymer that plays a crucial role in insect growth and development as a fundamental structural component of the exoskeleton.The membrane-integralβ-glycosyltransferase,chitin synthase,...Chitin is an abundant natural biopolymer that plays a crucial role in insect growth and development as a fundamental structural component of the exoskeleton.The membrane-integralβ-glycosyltransferase,chitin synthase,has been identified as the central component in chitin biosynthesis.However,the precise roles of other proteins in facilitating chitin synthase in chitin biosynthesis remain unclear.In this study,we employed split-ubiquitin membrane yeast two-hybrid(MYTH)and pull-down assays to demonstrate the physical interaction between Twinstar(Tsr),a small molecular protein in the actin-depolymerizing factor ADF/Cofilin protein family,and chitin synthase Krotzkopf verkehrt(Kkv)in Drosophila melanogaster in vitro.The RNA interference(RNAi)-mediated global knockdown of Tsr in D.melanogaster resulted in larval lethality.Furthermore,targeted suppression of Tsr in the tracheal and epidermal tissues also led to larval mortality,while knocking down Tsr in the wing tissues led to wrinkled wings.Additionally,silencing Tsr not only reduced the chitin content in the first longitudinal vein of the wings but also led to the absence of the chitin lamellar structure.To validate the functional conservation of Tsr in other insect orders,the two agricultural pests Ostrinia furnacalis and Tribolium castaneum,representing lepidoptera and coleoptera insects,respectively,were investigated.Knockdown experiments targeting the Drosophila Tsr orthologues OfTsr in O.furnacalis and TcTsr in T.castaneum produced abnormal larvae during molting or pupation in O.furnacalis and lethality in T.castaneum.Our findings not only improve ourknowledge of the chitin biosynthesis machinery in insect cuticles but also provide new potential targets for the control of major agricultural pests.展开更多
Foxtail millet(Setaria italica) is one of the primary multigrain crops originating from China, with a long history of cultivation and significant importance in Chinese farming civilization(Diao 2019). However, the exc...Foxtail millet(Setaria italica) is one of the primary multigrain crops originating from China, with a long history of cultivation and significant importance in Chinese farming civilization(Diao 2019). However, the excessive height of foxtail millet plants makes them susceptible to lodging, severely impacting the yield(Tian et al. 2010;Diao et al. 2024). During the “Green Revolution”, many types of cereals, including rice(Oryza sativa L.) and wheat(Triticum aestivum L.)(Brosius 1991;Peng et al. 1999), were bred to dwarf, resulting in significantly increased yields. Consequently, reducing plant height has become a key breeding objective for foxtail millet.展开更多
Iris domestica,a perennial herb of the Iridaceae family,is widely recognized for its rich isoflavone content and broad therapeutic properties.To elucidate the biosynthetic pathway of these medicinally significant comp...Iris domestica,a perennial herb of the Iridaceae family,is widely recognized for its rich isoflavone content and broad therapeutic properties.To elucidate the biosynthetic pathway of these medicinally significant compounds,we constructed a haplotype-resolved genome assembly of this species.Transcriptomic and metabolomic analyses revealed tissue-specific accumulation of isoflavone,particularly in rhizomes and roots.Functional characterization identified two candidate isoflavone synthase genes,among which IdIFS was confirmed to promote the biosynthesis of key compounds tectorigenin and irisflorentin.The high-quality genome assembly presented here provides a foundational resource for further research into the evolution,secondary metabolite,and environmental adaptation of I.domestica.展开更多
The evolutionarily conserved mitogen-activated protein kinase(MAPK)cascades relay extracellular signals into cells,triggering a variety of cellular responses.We previously revealed NtMPK4 as a positive regulator of ni...The evolutionarily conserved mitogen-activated protein kinase(MAPK)cascades relay extracellular signals into cells,triggering a variety of cellular responses.We previously revealed NtMPK4 as a positive regulator of nicotine biosynthesis;however,its upstream regulation remains unclear.Here,we characterized a MAPK cascade,comprising NtMEKK1b,NtMPKK2a,and NtMPK4,that promotes nicotine biosynthesis.This signaling module transduces external cues,including jasmonate and pathogen elicitors such as flg22,into post-translational modifications that enhance transcriptional activity and pathway gene expression.NtMPKK2a physically interacts with and phosphorylates NtMPK4 in vivo,confirming its role as an upstream kinase.RNAi-mediated silencing of NtMPKK2a significantly reduced the expression of nicotine pathway genes and decreased nicotine accumulation,whereas induced-overexpression of NtMPKK2a upregulated nicotine pathway genes and increased nicotine contents in tobacco hairy roots.Overexpression of NtMPKK2a in tobacco cells enhanced the transactivation activity of a NIC2-locus Ethylene Response Factor NtERF221 on Putrescine N-methyltransferase(NtPMT)promotor,further supporting its role in promoting nicotine biosynthesis.Furthermore,we identified NtMEKK1b,a tobacco MEKK that interacts with NtMAPKK2a in yeast cells.Knock-down of NtMEKK1b in transgenic tobacco plants attenuated the expression of nicotine pathway genes and reduced nicotine contents,whereas induced-overexpression of NtMEKK1b upregulated gene expression and nicotine accumulation.Our findings uncover a previously uncharacterized MAPK cascade module,NtMEKK1b-NtMPKK2a-NtMPK4,that regulates nicotine biosynthesis,highlighting the importance of posttranslational regulation in nicotine biosynthesis.展开更多
Acetolactate synthase(ALS)-targeting herbicides are among the most widely used weed-control chemicals globally.Mutations in the ALS gene can confer herbicide resistance in crops,thereby allowing selective elimination ...Acetolactate synthase(ALS)-targeting herbicides are among the most widely used weed-control chemicals globally.Mutations in the ALS gene can confer herbicide resistance in crops,thereby allowing selective elimination of weeds without harming crops.Herbicide-resistant ALS alleles were initially discovered in weeds and subsequently developed through artificial mutagenesis techniques.With the advancement of CRISPR/Cas technologies,various genome-editing tools are now available to introduce these resistant alleles,as well as novel variants,into diverse crop species.Moreover,emerging methodologies,such as directed evolution,enable the generation and screening of large populations of random ALS mutants.Consequently,ALS has become one of the most extensively targeted genes in plant gene evolution.This paper provides a comprehensive overview of both conventional and recently developed strategies for ALS evolution,with particular emphasis on CRISPR/Cas-based genome editing and directed evolution.Future perspectives on technological application are also discussed.By advancing our understanding of herbicide-resistant ALS allele development for crop improvement,these methodologies may also pave the way for their application to the evolution of other agronomically important genes.展开更多
The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tub...The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tubers is regulated remains poorly understood.In this study,we identified and functionally validated key transcription factors that regulate anthocyanin biosynthesis based on a comparative transcriptome and metabolome analysis of three D.alata cultivars with different colored tubers(dark purple,light purple,and white).The anthocyanin glycoside cyanidin-3-O-(2′′-O-glucosyl)glucoside was abundant during early tuber development,and we determined that its accumulation is regulated in opposite manners by two R2R3-MYB transcription factors:DaMYB75 and DaMYB56.Yeast two-hybrid and bimolecular fluorescence complementation assays in Nicotiana benthamiana and co-expression assays in D.alata demonstrated that DaMYB75 promotes anthocyanin biosynthesis by specifically activating the promoter of the late anthocyanin biosynthesis gene DaANS and enhancing its expression through an interaction with DabHLH72.By contrast,DaMYB56 is a negative regulator of anthocyanin biosynthesis that binds to the DaANS promoter together with DabHLH72.Furthermore,the methylation levels of the DaMYB75 promoter were significantly lower in purple tubers than in white tubers.These findings shed light on the regulation of anthocyanin biosynthesis by MYBs and provide the basis for genetically improving anthocyanin content in D.alata.展开更多
Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the bi...Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.展开更多
Carotenoids are natural pigments that are widely distributed in the flowers,fruits,and seeds of many plant species.These compounds not only endow diverse colors but also exhibit antioxidant,immune-modulatory,anti-agin...Carotenoids are natural pigments that are widely distributed in the flowers,fruits,and seeds of many plant species.These compounds not only endow diverse colors but also exhibit antioxidant,immune-modulatory,anti-aging,and photoprotective properties.Although carotenoid metabolism has been studied extensively in microbial and plant science,the genetic mechanisms underlying carotenoid metabolism in cotton remain underexplored.Here,we isolated gene GbDYA that regulates a dark-yellow anther color by map-based cloning using a BC1F1 population derived from a cross of Gossypium barbadense acc.Hai7124 with dark-yellow anthers and G.hirsutum acc.TM-1 with light-yellow anthers backcrossed with TM-1.GbDYA encodes phytoene synthase,a key rate-limiting enzyme in the carotenoid biosynthesis pathway.A long terminal repeat retrotransposon in the first exon of GhDYA(an ortholog of GbDYA in G.hirsutum acc.TM-1)caused loss of function and led to the light-yellow anther color.GbDYA is predominantly expressed in the early stages of anther development.Transcriptome,RT-qPCR and KEGG enrichment analyses revealed that GbDYA influences the synthesis and accumulation of carotenoids in anthers by modulating expression of key genes in the carotenoid biosynthesis pathway.Integrated transcriptomic and metabolomic analyses indicated that the accumulation of lutein,violaxanthin,antherxanthin,cryptoxanthin,zeaxanthin,andβ-carotene contributed to yellow coloration of anthers.Dual-luciferase and yeast one-hybrid assays confirmed that transcription factor GbMYB105(GB_A11G3511)binds to the promoter of GbDYA and activates its expression.High-temperature stress treatment indicated that carotenoids accumulation in anthers enhances pollen antioxidant activity.This study unravels the role of GbDYA in conferring the anther coloration,and provides the potential utilization by modulating accumulation of carotenoids in anthers to enhance pollen viability in high-temperature tolerance breeding in cotton.展开更多
Lignin is a significant secondary metabolite produced through the phenylpropanoid pathway.As a vital component of the plant cell wall,lignin affects various fruit characteristics,including size,seed quantity,and firmn...Lignin is a significant secondary metabolite produced through the phenylpropanoid pathway.As a vital component of the plant cell wall,lignin affects various fruit characteristics,including size,seed quantity,and firmness.In this study,we conducted comprehensive identification and phylogenetic analysis of 265 Caffeic acid O-methyltransferase(COMT)genes across ten different plant species,including Vaccinium corymbosum and four other Vaccinium species.The results reveal that VcCOMT38 is a promising structural gene for the biosynthesis of lignin in blueberry.An in vitro enzymatic assay of VcCOMT38 demonstrated that it is a special enzyme in the lignin biosynthesis pathway and prefers to use caffeic acid as a substrate over 5-hydroxyferulic acid.Transient overexpression and silencing of VcCOMT38 in Vaccinium corymbosum‘Northland’fruits demonstrated that VcCOMT38 participates in lignin biosynthesis and contributes to both an increased number of immature seeds and enhanced fruit firmness.The heterologous overexpression of VcCOMT38 in Nicotiana benthamiana revealed that this gene could increase the lignin content and the syringyl/guaiacyl(S/G)ratio,which determines the maximum monomer yield during lignin depolymerization.These results highlight VcCOMT38 as a crucial gene in lignin biosynthesis and its potential for improving lignin production in industry through genetically modified woody plants.展开更多
Flavonoids are crucial secondary metabolites widely distributed in plants,playing vital roles in diverse biological processes.Although the flavonoid biosynthesis pathway has been extensively characterized,the transcri...Flavonoids are crucial secondary metabolites widely distributed in plants,playing vital roles in diverse biological processes.Although the flavonoid biosynthesis pathway has been extensively characterized,the transcriptional regulatory mechanisms remain poorly understood.In this study,we identify the miR166–ATHB14-LIKE module comprising the miR166 and its target gene ATHB14-LIKE as a key regulator of flavonoid biosynthesis in soybean(Glycine max).Knockdown of miR166 or overexpression of ATHB14-LIKE upregulated multiple flavonoid biosynthesis genes,leading to increased flavonoid accumulation.Conversely,miR166 overexpression suppressed these genes and reduced flavonoid levels.We further show that ATHB14-LIKE directly activates specific flavonoid biosynthesis genes by binding to their promoters.Additionally,ATHB14-LIKE forms homodimers and heterodimers with homologous proteins to regulate downstream flavonoid biosynthesis genes.Together,our findings demonstrate that the miR166–ATHB14-LIKE module controls soybean flavonoid content by coordinating the expression of key biosynthetic genes.展开更多
Locust plagues result in significant agricultural and ecological damage,and the current dependence on broadspectrum chemical pesticides raises serious concerns regarding environmental sustainability and public health....Locust plagues result in significant agricultural and ecological damage,and the current dependence on broadspectrum chemical pesticides raises serious concerns regarding environmental sustainability and public health.In this study,we elucidated the biosynthetic pathway of the locust aggregation pheromone 4-vinylanisole(4VA).Through analysis of the crystal structure of the 4VPMT2-4VA-SAM complex,it was determined that 4-nitrophenol acts as a substrate analogue,effectively inhibiting 4VPMT enzyme activity and thereby preventing the formation of 4VA.This study revealed key enzymatic targets and lead inhibitors for intervention,establishing a molecular foundation for pheromone-based,environmentally sustainable locust control strategies and offering a viable alternative to reduce reliance on conventional chemical pesticides.展开更多
UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important...UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important floral and fruity characteristic aroma.UV-B treatment significantly improved the aroma quality of‘Foshou’and‘Yuquan’oolong teas,increasing a-farnesene levels by 1.8-and 1.4-fold,respectively.The a-farnesene synthase(CsAFS),ELONGATED HYPOCOTYL 5(CsHY5),and myelocytomatosis protein 2(CsMYC2)exhibited a highly correlated expression pattern closely associated with a-farnesene accumulation.Single-factor treatment revealed that CsAFS expression was induced by both UV-B and mechanical wounding,with CsHY5 predominantly responding to UV-B radiation,while CsMYC2 primarily responded to tumbling-induced mechanical wounding signal.Transient suppression of CsHY5 in tea leaves reduced the expression of both CsAFS and CsMYC2 whereas CsMYC2 suppression decreased CsAFS expression.G-box motifs were identified in promoters of CsMYC2 and CsAFS,and the dual-luciferase reporter assay(LUC)and electrophoretic mobility shift assays(EMSA)demonstrated direct binding functions of CsHY5 to CsAFS and CsMYC2 promoters,as well as CsMYC2 to the CsAFS promoter.Based on sensory evaluation,odourant quantification,gene expression,and molecular functional analysis,we propose that UV-B radiation and tumbling-induced wounding signals synergistically regulate a-farnesene biosynthesis through a coordinated interaction of CsHY5 and CsMYC2 during oolong tea processing.These findings improve our understanding of flavour formation during oolong tea production and also provide novel insights into artificial light application in tea manufacturing.展开更多
Flavonoids,abundant in the fruits,are pivotal to their growth,development,and storage.In addition,they have significant beneficial effects on human health.Consequently,research is increasingly concentrating on the reg...Flavonoids,abundant in the fruits,are pivotal to their growth,development,and storage.In addition,they have significant beneficial effects on human health.Consequently,research is increasingly concentrating on the regulatory mechanisms governing flavonoid biosynthesis in fruits.Phytohormones are involved in the regulation of flavonoid biosynthesis.The abscisic acid,ethylene,jasmonic acid,cytokinins,and brassinosteroids promote flavonoid biosynthesis,while auxin negatively regulates flavonoid biosynthesis.Subsequently,transcription factors from the MYB,bHLH,WRKY,NAC,and bZIP families are pivotal in regulating flavonoid biosynthesis.In addition,non-coding RNAs(microRNA and lncRNA)also participate in the regulation of flavonoids biosynthesis.MicroRNAs are generally believed to negatively regulate flavonoid metabolism in fruits,while lncRNAs have the opposite effect.Furthermore,the interactions between plant hormones,transcription factors,and non-coding RNAs in fruit flavonoid biosynthesis were analyzed.Ultimately,a foundational regulatory network for fruit flavonoid biosynthesis was hereby established.展开更多
Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassi...Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions.展开更多
Proanthocyanidins(PAs)are a group of oligomeric flavonoids also known as condensed tannins.PAs in human diet have antioxidant and health-promoting effects.BSISTER(BS)promotes the accumulation of PAs,but its direct tar...Proanthocyanidins(PAs)are a group of oligomeric flavonoids also known as condensed tannins.PAs in human diet have antioxidant and health-promoting effects.BSISTER(BS)promotes the accumulation of PAs,but its direct target gene and regulation mechanism in PAs biosynthesis are not clear.Here,we reported VviBS1 and VviBS2 genes,which bind directly to the promoter of PA synthesis key genes VviANR(ANTHOCYANIDIN REDUCTASE)and VviLAR(LEUCOANTHOCYANIDIN REDUCTASE)and up-regulate their expression to promote the PAs biosynthesis in grapevine.VviBS1 and VviBS2 partially rescued the transparent testa phenotype of an Arabidopsis tt16 mutant.Overexpression of BS1 and BS2 in grapevine callus increased the content of PAs,as well as the expression of specific genes related to PA synthesis.VviBS1 and VviBS2 proteins bound directly to the promoter regions of the key PA synthesis genes VviANR1,VviANR2,and VviLAR1.Overexpression of VviBS1 and VviBS2 promotes VviANR1,VviANR2 and VviLAR1 expression and PAs biosynthesis.Some BS1-and BS2-interacting MADS-box proteins have an effect on PAs biosynthesis.This study provides insight into the regulatory mechanisms of PAs biosynthesis in grapevine,which could be effectively employed for metabolic engineering to increase PA content.展开更多
Flower color is an essential trait in ornamental plant breeding. Lycoris longituba is a popular ornamental plant native to central eastern China. The decrease in anthocyanin accumulation causes L. longituba petal colo...Flower color is an essential trait in ornamental plant breeding. Lycoris longituba is a popular ornamental plant native to central eastern China. The decrease in anthocyanin accumulation causes L. longituba petal color fading during flower development, which considerably affects the ornamental value of L. longituba. However, mechanisms underlying anthocyanin biosynthesis inhibition during L. longituba petal development remain unclear. In this study, three LlDFR genes were confirmed to be involved in anthocyanin biosynthesis and LlDFRc exerted the strongest promoting effect on anthocyanin accumulation. According to the correlation analysis results, LlbHLH12 exhibited the strongest negative correlation with LlDFRc. Quantitative real-time PCR analysis showed that LlbHLH12 was highly expressed during the medium bud and full bloom stages of flower development. LlbHLH12 was identified as a member of subgroup XII of bHLH transcription factor family. Subcellular localization and transcriptional activation ability assay revealed that LlbHLH12 was located in the nucleus without transcriptional activation activity. Overexpression of LlbHLH12 in Nicotiana tabacum and L. longituba inhibited anthocyanin accumulation by suppressing the expression of anthocyanin biosynthetic pathway genes. Furthermore, yeast one-hybrid, dual-luciferase, and β-glucuronidase activity assays showed that LlbHLH12 directly bound to the promoters of LlPAL and LlDFRc and suppressed their expression to inhibit anthocyanin biosynthesis. Overall, our study identified a novel bHLH repressor negatively regulating anthocyanin biosynthesis and provided new insights into the molecular mechanisms underlying color fading in L. longituba petals.展开更多
YdjC chitooligosaccharide deacetylase homolog(YDJC)has been identified as a susceptibility gene for inflammatory bowel disease(IBD),yet its role in the pathogenesis of IBD,particularly in regulating immune responses i...YdjC chitooligosaccharide deacetylase homolog(YDJC)has been identified as a susceptibility gene for inflammatory bowel disease(IBD),yet its role in the pathogenesis of IBD,particularly in regulating immune responses in the gut mucosa,remains elusive.In this study,we demonstrated that YDJC expression is downregulated in inflamed mucosa,particularly in the CD4^(+)T cells of IBD patients,and that Ydjc deficiency promotes CD4^(+)T-cell proliferation and Th1 cell differentiation,thereby exacerbating acute and chronic colitis in mice.Integrative transcriptomic,proteomic,and metabolomic analyses revealed that Ydjc^(-/-)CD4^(+)T cells exhibit upregulated SREBP2-mediated cholesterol biosynthesis.Consistently,treatment with key enzyme inhibitors targeting cholesterol biosynthesis,including simvastatin,fatostatin,and AAV-sh-Srebf2,markedly suppressed CD4^(+)T-cell proliferation and Th1 cell differentiation,thereby alleviating colitis in Ydjc^(-/-)mice.Mechanistically,YDJC directly deacetylates SREBP2,which further suppresses downstream target gene expression(e.g.,Hmgcr,Hmgcs1,and Cyp51).Therefore,our findings elucidate a novel mechanism whereby YDJC restrains intestinal mucosal inflammation by downregulating SREBP2-driven Th1 cell differentiation,suggesting that targeting YDJC and SREBP2-mediated cholesterol biosynthesis may serve as promising therapeutic strategies for IBD.展开更多
Artemisia annua L. produces small amounts of the sesquiterpenoid artemisinin, which is used for treatment of malaria. A worldwide shortage of the drug has led to intense research to increase the yield of artemisinin i...Artemisia annua L. produces small amounts of the sesquiterpenoid artemisinin, which is used for treatment of malaria. A worldwide shortage of the drug has led to intense research to increase the yield of artemisinin in the plant. In order to study the regulation of expression of a key enzyme of artemisinin biosynthesis, the promoter region of the key enzyme amorpha-4,11-diene synthase (ADS) was cloned and fused with the β-glucuronidase (GUS) reporter gene. Transgenic plants of A. annua expressing this fusion were generated and studied. Transgenic plants expressing the GUS gene were used to establish the activity of the cloned promoter by a GUS activity staining procedure. GUS under the control of the ADS promoter showed specific expression in glandular trichomes. The activity of the ADS promoter varies temporally and in old tissues essentially no GUS staining could be observed. The expression pattern of GUS and ADS in aerial parts of the transgenic plant was essentially the same indicating that the cis-elements controlling glandular trichome specific expression are included in the cloned promoter. However, some cis-element(s) that control expression in root and old leaf appears to be missing in the cloned promoter. Furthermore, qPCR was used to compare the activity of the wild-type ADS promoter with that of the cloned ADS promoter. The latter promoter showed a considerably lower activity than the wild-type promoter as judged from the levels of GUS and ADS transcripts, respectively, which may be due to the removal of an enhancing cis-element from the ADS promoter. The ADS gene is specifically expressed in stalk and secretory cells of glandular trichomes of A. annua.展开更多
Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose content.We invest...Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose content.We investigated the effect of SSI suppression on grain quality traits,starch biosynthesis,and amylopectin chain distribution in rice plants exposed to two different temperature regimes.The activities and transcripts of BEs,DBEs,and other SS isoforms were further investigated to clarify the effect of SSI suppression on these key enzymes and their specific isoforms under different temperature treatments.Suppression of SSI by RNAi altered grain starch component and amylopectin chain distribution,but it exerted only a slight effect on total starch content(%)and accumulation amount(mg kernel?1)and on starch granule morphology and particle size distribution.Under normal temperature(NT),insignificant differences in kernel weight,chalky kernel proportion,chalky degree,and starch granule morphology between SSI-RNAi line and its wild type(WT)were observed.However,amylose content(AC)level and granule-bound starch synthase(GBSS)activity in rice endosperms were markedly increased by SSI-RNAi suppression.The chalky kernel proportion and chalky degree of SSIRNAi lines were significantly higher than those of WT under high temperature(HT)exposure at filling stage.Inhibition of SSI by RNAi affected amylopectin chain distribution and raised starch gelatinization temperature(GT)in two ways:directly from the SSI deficiency itself and indirectly by reducing BEIIb amounts in an SSI-deficient background.The deficiency of SSI expression led to an alteration in the susceptibility of grain chalkiness occurrence and starch gelatinization temperature to HT exposure,owing to a pleiotropic effect of SSI deficiency on the expression of other genes associated with starch biosynthesis.展开更多
Terpenoid indole(TIAs)andβ-carboline alkaloids(BCAs),such as suppressant reserpine,vasodilatory yohimbine,and antimalarial quinine,are natural compounds derived from strictosidine.These compounds can exert powerful p...Terpenoid indole(TIAs)andβ-carboline alkaloids(BCAs),such as suppressant reserpine,vasodilatory yohimbine,and antimalarial quinine,are natural compounds derived from strictosidine.These compounds can exert powerful pharmacological effects but be obtained from limited source in nature.the whole biosynthetic pathway of TIAs and BCAs,The Pictet–Spengler reaction catalyzed by strictosidine synthase(STR;EC:4.3.3.2)is the rate-limiting step.Therefore,it is necessary to investigate their biosynthesis pathways,especially the role of STR,and related findings will support the biosynthetic generation of natural and unnatural compounds.This review summarizes the latest studies concerning the function of STR in TIA and BCA biosynthesis,and illustrates the compounds derived from strictosidine.The substrate specificity of STR based on its structure is also summarized.Proteins that contain sixbladed four-strandedβ-propeller folds in many organisms,other than plants,are listed.The presence of these folds may lead to similar functions among organisms.The expression of STR gene can greatly influence the production of many compounds.STR is mainly applied to product various valuable drugs in plant cell suspension culture and biosynthesis in other carriers.展开更多
基金supported by the National Natural Science Foundation of China(32161133010)the National Key Research and Development Program of China(2022YFD1700200)+2 种基金the Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-CSCB-202302)the Shenzhen Science and Technology Program,China(KQTD20180411143628272)the Special Funds for Science Technology Innovation and Industrial Development of Shenzhen Dapeng New District,China(PT202101-02).
文摘Chitin is an abundant natural biopolymer that plays a crucial role in insect growth and development as a fundamental structural component of the exoskeleton.The membrane-integralβ-glycosyltransferase,chitin synthase,has been identified as the central component in chitin biosynthesis.However,the precise roles of other proteins in facilitating chitin synthase in chitin biosynthesis remain unclear.In this study,we employed split-ubiquitin membrane yeast two-hybrid(MYTH)and pull-down assays to demonstrate the physical interaction between Twinstar(Tsr),a small molecular protein in the actin-depolymerizing factor ADF/Cofilin protein family,and chitin synthase Krotzkopf verkehrt(Kkv)in Drosophila melanogaster in vitro.The RNA interference(RNAi)-mediated global knockdown of Tsr in D.melanogaster resulted in larval lethality.Furthermore,targeted suppression of Tsr in the tracheal and epidermal tissues also led to larval mortality,while knocking down Tsr in the wing tissues led to wrinkled wings.Additionally,silencing Tsr not only reduced the chitin content in the first longitudinal vein of the wings but also led to the absence of the chitin lamellar structure.To validate the functional conservation of Tsr in other insect orders,the two agricultural pests Ostrinia furnacalis and Tribolium castaneum,representing lepidoptera and coleoptera insects,respectively,were investigated.Knockdown experiments targeting the Drosophila Tsr orthologues OfTsr in O.furnacalis and TcTsr in T.castaneum produced abnormal larvae during molting or pupation in O.furnacalis and lethality in T.castaneum.Our findings not only improve ourknowledge of the chitin biosynthesis machinery in insect cuticles but also provide new potential targets for the control of major agricultural pests.
基金supported by the National Natural Science Foundation of China (32200222)the High-level Talents Start-up Fund of Shanxi Agricultural University, China (J242198006)+2 种基金the Start-up Fund of Shanxi Agricultural University, China (2021BQ84)the Shanxi Province Outstanding Doctoral and Post-Doctoral Scholarship Award Foundation,China(SXBYKY 2021055 and SXBYKY2022033)the Houji Laboratory Foundation, China (202204010910001-32)。
文摘Foxtail millet(Setaria italica) is one of the primary multigrain crops originating from China, with a long history of cultivation and significant importance in Chinese farming civilization(Diao 2019). However, the excessive height of foxtail millet plants makes them susceptible to lodging, severely impacting the yield(Tian et al. 2010;Diao et al. 2024). During the “Green Revolution”, many types of cereals, including rice(Oryza sativa L.) and wheat(Triticum aestivum L.)(Brosius 1991;Peng et al. 1999), were bred to dwarf, resulting in significantly increased yields. Consequently, reducing plant height has become a key breeding objective for foxtail millet.
文摘Iris domestica,a perennial herb of the Iridaceae family,is widely recognized for its rich isoflavone content and broad therapeutic properties.To elucidate the biosynthetic pathway of these medicinally significant compounds,we constructed a haplotype-resolved genome assembly of this species.Transcriptomic and metabolomic analyses revealed tissue-specific accumulation of isoflavone,particularly in rhizomes and roots.Functional characterization identified two candidate isoflavone synthase genes,among which IdIFS was confirmed to promote the biosynthesis of key compounds tectorigenin and irisflorentin.The high-quality genome assembly presented here provides a foundational resource for further research into the evolution,secondary metabolite,and environmental adaptation of I.domestica.
基金supported partially by the Kentucky Tobacco Research and Development Center(KTRDC),University of Kentucky.
文摘The evolutionarily conserved mitogen-activated protein kinase(MAPK)cascades relay extracellular signals into cells,triggering a variety of cellular responses.We previously revealed NtMPK4 as a positive regulator of nicotine biosynthesis;however,its upstream regulation remains unclear.Here,we characterized a MAPK cascade,comprising NtMEKK1b,NtMPKK2a,and NtMPK4,that promotes nicotine biosynthesis.This signaling module transduces external cues,including jasmonate and pathogen elicitors such as flg22,into post-translational modifications that enhance transcriptional activity and pathway gene expression.NtMPKK2a physically interacts with and phosphorylates NtMPK4 in vivo,confirming its role as an upstream kinase.RNAi-mediated silencing of NtMPKK2a significantly reduced the expression of nicotine pathway genes and decreased nicotine accumulation,whereas induced-overexpression of NtMPKK2a upregulated nicotine pathway genes and increased nicotine contents in tobacco hairy roots.Overexpression of NtMPKK2a in tobacco cells enhanced the transactivation activity of a NIC2-locus Ethylene Response Factor NtERF221 on Putrescine N-methyltransferase(NtPMT)promotor,further supporting its role in promoting nicotine biosynthesis.Furthermore,we identified NtMEKK1b,a tobacco MEKK that interacts with NtMAPKK2a in yeast cells.Knock-down of NtMEKK1b in transgenic tobacco plants attenuated the expression of nicotine pathway genes and reduced nicotine contents,whereas induced-overexpression of NtMEKK1b upregulated gene expression and nicotine accumulation.Our findings uncover a previously uncharacterized MAPK cascade module,NtMEKK1b-NtMPKK2a-NtMPK4,that regulates nicotine biosynthesis,highlighting the importance of posttranslational regulation in nicotine biosynthesis.
基金Guangdong Basic and Applied Basic Research Foundation(2023B1515120050,2023A1515110529 and 2024A1515012454)Shenzhen Science and Technology Program(JCYJ20230807145759008 and KJZD20240903100206009).
文摘Acetolactate synthase(ALS)-targeting herbicides are among the most widely used weed-control chemicals globally.Mutations in the ALS gene can confer herbicide resistance in crops,thereby allowing selective elimination of weeds without harming crops.Herbicide-resistant ALS alleles were initially discovered in weeds and subsequently developed through artificial mutagenesis techniques.With the advancement of CRISPR/Cas technologies,various genome-editing tools are now available to introduce these resistant alleles,as well as novel variants,into diverse crop species.Moreover,emerging methodologies,such as directed evolution,enable the generation and screening of large populations of random ALS mutants.Consequently,ALS has become one of the most extensively targeted genes in plant gene evolution.This paper provides a comprehensive overview of both conventional and recently developed strategies for ALS evolution,with particular emphasis on CRISPR/Cas-based genome editing and directed evolution.Future perspectives on technological application are also discussed.By advancing our understanding of herbicide-resistant ALS allele development for crop improvement,these methodologies may also pave the way for their application to the evolution of other agronomically important genes.
基金supported by the National Natural Science Foundation of China(32460767)Jiangxi Provincial Key Research and Development Program(20232BBF60007)Jiangxi Provincial Natural Science Foundation(20224BAB205024).
文摘The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tubers is regulated remains poorly understood.In this study,we identified and functionally validated key transcription factors that regulate anthocyanin biosynthesis based on a comparative transcriptome and metabolome analysis of three D.alata cultivars with different colored tubers(dark purple,light purple,and white).The anthocyanin glycoside cyanidin-3-O-(2′′-O-glucosyl)glucoside was abundant during early tuber development,and we determined that its accumulation is regulated in opposite manners by two R2R3-MYB transcription factors:DaMYB75 and DaMYB56.Yeast two-hybrid and bimolecular fluorescence complementation assays in Nicotiana benthamiana and co-expression assays in D.alata demonstrated that DaMYB75 promotes anthocyanin biosynthesis by specifically activating the promoter of the late anthocyanin biosynthesis gene DaANS and enhancing its expression through an interaction with DabHLH72.By contrast,DaMYB56 is a negative regulator of anthocyanin biosynthesis that binds to the DaANS promoter together with DabHLH72.Furthermore,the methylation levels of the DaMYB75 promoter were significantly lower in purple tubers than in white tubers.These findings shed light on the regulation of anthocyanin biosynthesis by MYBs and provide the basis for genetically improving anthocyanin content in D.alata.
基金supported by CARS(CARS-21),the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-032)the Science and Technology Department of Xizang(XZ202401ZY0020)+2 种基金the Science and Technology Department of Sichuan Province(2023YFH0044,2023YFH0018)the Sichuan Province Science Foundation for Distinguished Young Scholars(2022JDJQ0006)the Doctoral Fund of Southwest University of Science and Technology(19ZX7117,21ZX7116).
文摘Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.
基金financially supported in part by grants from Biological Breeding-National Science and Technology Major Project (2023ZD04040)Jiangsu Key Research and Development Program (BE2022384)Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CICMCP) (No. 10)
文摘Carotenoids are natural pigments that are widely distributed in the flowers,fruits,and seeds of many plant species.These compounds not only endow diverse colors but also exhibit antioxidant,immune-modulatory,anti-aging,and photoprotective properties.Although carotenoid metabolism has been studied extensively in microbial and plant science,the genetic mechanisms underlying carotenoid metabolism in cotton remain underexplored.Here,we isolated gene GbDYA that regulates a dark-yellow anther color by map-based cloning using a BC1F1 population derived from a cross of Gossypium barbadense acc.Hai7124 with dark-yellow anthers and G.hirsutum acc.TM-1 with light-yellow anthers backcrossed with TM-1.GbDYA encodes phytoene synthase,a key rate-limiting enzyme in the carotenoid biosynthesis pathway.A long terminal repeat retrotransposon in the first exon of GhDYA(an ortholog of GbDYA in G.hirsutum acc.TM-1)caused loss of function and led to the light-yellow anther color.GbDYA is predominantly expressed in the early stages of anther development.Transcriptome,RT-qPCR and KEGG enrichment analyses revealed that GbDYA influences the synthesis and accumulation of carotenoids in anthers by modulating expression of key genes in the carotenoid biosynthesis pathway.Integrated transcriptomic and metabolomic analyses indicated that the accumulation of lutein,violaxanthin,antherxanthin,cryptoxanthin,zeaxanthin,andβ-carotene contributed to yellow coloration of anthers.Dual-luciferase and yeast one-hybrid assays confirmed that transcription factor GbMYB105(GB_A11G3511)binds to the promoter of GbDYA and activates its expression.High-temperature stress treatment indicated that carotenoids accumulation in anthers enhances pollen antioxidant activity.This study unravels the role of GbDYA in conferring the anther coloration,and provides the potential utilization by modulating accumulation of carotenoids in anthers to enhance pollen viability in high-temperature tolerance breeding in cotton.
文摘Lignin is a significant secondary metabolite produced through the phenylpropanoid pathway.As a vital component of the plant cell wall,lignin affects various fruit characteristics,including size,seed quantity,and firmness.In this study,we conducted comprehensive identification and phylogenetic analysis of 265 Caffeic acid O-methyltransferase(COMT)genes across ten different plant species,including Vaccinium corymbosum and four other Vaccinium species.The results reveal that VcCOMT38 is a promising structural gene for the biosynthesis of lignin in blueberry.An in vitro enzymatic assay of VcCOMT38 demonstrated that it is a special enzyme in the lignin biosynthesis pathway and prefers to use caffeic acid as a substrate over 5-hydroxyferulic acid.Transient overexpression and silencing of VcCOMT38 in Vaccinium corymbosum‘Northland’fruits demonstrated that VcCOMT38 participates in lignin biosynthesis and contributes to both an increased number of immature seeds and enhanced fruit firmness.The heterologous overexpression of VcCOMT38 in Nicotiana benthamiana revealed that this gene could increase the lignin content and the syringyl/guaiacyl(S/G)ratio,which determines the maximum monomer yield during lignin depolymerization.These results highlight VcCOMT38 as a crucial gene in lignin biosynthesis and its potential for improving lignin production in industry through genetically modified woody plants.
基金the Projects of Science and Technology of Shanghai(22N11900400)Key Projects of Beijing Institute of Life Science and Technology(2024400CB0050)+1 种基金National Natural Science Foundation of China(32488102)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24030303)。
文摘Flavonoids are crucial secondary metabolites widely distributed in plants,playing vital roles in diverse biological processes.Although the flavonoid biosynthesis pathway has been extensively characterized,the transcriptional regulatory mechanisms remain poorly understood.In this study,we identify the miR166–ATHB14-LIKE module comprising the miR166 and its target gene ATHB14-LIKE as a key regulator of flavonoid biosynthesis in soybean(Glycine max).Knockdown of miR166 or overexpression of ATHB14-LIKE upregulated multiple flavonoid biosynthesis genes,leading to increased flavonoid accumulation.Conversely,miR166 overexpression suppressed these genes and reduced flavonoid levels.We further show that ATHB14-LIKE directly activates specific flavonoid biosynthesis genes by binding to their promoters.Additionally,ATHB14-LIKE forms homodimers and heterodimers with homologous proteins to regulate downstream flavonoid biosynthesis genes.Together,our findings demonstrate that the miR166–ATHB14-LIKE module controls soybean flavonoid content by coordinating the expression of key biosynthetic genes.
基金support of the National Natural Science Foundation of China(32472594).
文摘Locust plagues result in significant agricultural and ecological damage,and the current dependence on broadspectrum chemical pesticides raises serious concerns regarding environmental sustainability and public health.In this study,we elucidated the biosynthetic pathway of the locust aggregation pheromone 4-vinylanisole(4VA).Through analysis of the crystal structure of the 4VPMT2-4VA-SAM complex,it was determined that 4-nitrophenol acts as a substrate analogue,effectively inhibiting 4VPMT enzyme activity and thereby preventing the formation of 4VA.This study revealed key enzymatic targets and lead inhibitors for intervention,establishing a molecular foundation for pheromone-based,environmentally sustainable locust control strategies and offering a viable alternative to reduce reliance on conventional chemical pesticides.
基金supported by the National Natural Science Foundation of China(Grant No.32072623)the National Key Research and Development Program of China(Grant No.2021YFD1601103).
文摘UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important floral and fruity characteristic aroma.UV-B treatment significantly improved the aroma quality of‘Foshou’and‘Yuquan’oolong teas,increasing a-farnesene levels by 1.8-and 1.4-fold,respectively.The a-farnesene synthase(CsAFS),ELONGATED HYPOCOTYL 5(CsHY5),and myelocytomatosis protein 2(CsMYC2)exhibited a highly correlated expression pattern closely associated with a-farnesene accumulation.Single-factor treatment revealed that CsAFS expression was induced by both UV-B and mechanical wounding,with CsHY5 predominantly responding to UV-B radiation,while CsMYC2 primarily responded to tumbling-induced mechanical wounding signal.Transient suppression of CsHY5 in tea leaves reduced the expression of both CsAFS and CsMYC2 whereas CsMYC2 suppression decreased CsAFS expression.G-box motifs were identified in promoters of CsMYC2 and CsAFS,and the dual-luciferase reporter assay(LUC)and electrophoretic mobility shift assays(EMSA)demonstrated direct binding functions of CsHY5 to CsAFS and CsMYC2 promoters,as well as CsMYC2 to the CsAFS promoter.Based on sensory evaluation,odourant quantification,gene expression,and molecular functional analysis,we propose that UV-B radiation and tumbling-induced wounding signals synergistically regulate a-farnesene biosynthesis through a coordinated interaction of CsHY5 and CsMYC2 during oolong tea processing.These findings improve our understanding of flavour formation during oolong tea production and also provide novel insights into artificial light application in tea manufacturing.
基金supported by the China Agricultural Research System(Grant No.CARS-09)the Central Government Guiding Local Science and Technology Development Project(Grant No.YDZX2023029)the Gansu Planning Projects on Science and Technology(Grant No.23CXNJ0013).
文摘Flavonoids,abundant in the fruits,are pivotal to their growth,development,and storage.In addition,they have significant beneficial effects on human health.Consequently,research is increasingly concentrating on the regulatory mechanisms governing flavonoid biosynthesis in fruits.Phytohormones are involved in the regulation of flavonoid biosynthesis.The abscisic acid,ethylene,jasmonic acid,cytokinins,and brassinosteroids promote flavonoid biosynthesis,while auxin negatively regulates flavonoid biosynthesis.Subsequently,transcription factors from the MYB,bHLH,WRKY,NAC,and bZIP families are pivotal in regulating flavonoid biosynthesis.In addition,non-coding RNAs(microRNA and lncRNA)also participate in the regulation of flavonoids biosynthesis.MicroRNAs are generally believed to negatively regulate flavonoid metabolism in fruits,while lncRNAs have the opposite effect.Furthermore,the interactions between plant hormones,transcription factors,and non-coding RNAs in fruit flavonoid biosynthesis were analyzed.Ultimately,a foundational regulatory network for fruit flavonoid biosynthesis was hereby established.
基金funded by the National Natural Science Foundation of China (31760363)the Earmarked Fund for CARS (CARS-14-1-16)+1 种基金the Gansu Education Science and Technology Innovation Industry Support Program,China (2021CYZC-38)the Gansu Provincial Key Laboratory of Arid Land Crop Science,Gansu Agricultural University,China (GSCS-2020-Z6)。
文摘Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions.
基金funded by the Key R&D Program of Shaanxi province(Grant Nos.2023-ZDLNY-23 and 2023XCZX2-18)the National Key R&D Program of China(Grant No.2019YFD1001405).
文摘Proanthocyanidins(PAs)are a group of oligomeric flavonoids also known as condensed tannins.PAs in human diet have antioxidant and health-promoting effects.BSISTER(BS)promotes the accumulation of PAs,but its direct target gene and regulation mechanism in PAs biosynthesis are not clear.Here,we reported VviBS1 and VviBS2 genes,which bind directly to the promoter of PA synthesis key genes VviANR(ANTHOCYANIDIN REDUCTASE)and VviLAR(LEUCOANTHOCYANIDIN REDUCTASE)and up-regulate their expression to promote the PAs biosynthesis in grapevine.VviBS1 and VviBS2 partially rescued the transparent testa phenotype of an Arabidopsis tt16 mutant.Overexpression of BS1 and BS2 in grapevine callus increased the content of PAs,as well as the expression of specific genes related to PA synthesis.VviBS1 and VviBS2 proteins bound directly to the promoter regions of the key PA synthesis genes VviANR1,VviANR2,and VviLAR1.Overexpression of VviBS1 and VviBS2 promotes VviANR1,VviANR2 and VviLAR1 expression and PAs biosynthesis.Some BS1-and BS2-interacting MADS-box proteins have an effect on PAs biosynthesis.This study provides insight into the regulatory mechanisms of PAs biosynthesis in grapevine,which could be effectively employed for metabolic engineering to increase PA content.
基金supported by the National Natural Science Foundation of China(Grant Nos.31870695,32071828)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Flower color is an essential trait in ornamental plant breeding. Lycoris longituba is a popular ornamental plant native to central eastern China. The decrease in anthocyanin accumulation causes L. longituba petal color fading during flower development, which considerably affects the ornamental value of L. longituba. However, mechanisms underlying anthocyanin biosynthesis inhibition during L. longituba petal development remain unclear. In this study, three LlDFR genes were confirmed to be involved in anthocyanin biosynthesis and LlDFRc exerted the strongest promoting effect on anthocyanin accumulation. According to the correlation analysis results, LlbHLH12 exhibited the strongest negative correlation with LlDFRc. Quantitative real-time PCR analysis showed that LlbHLH12 was highly expressed during the medium bud and full bloom stages of flower development. LlbHLH12 was identified as a member of subgroup XII of bHLH transcription factor family. Subcellular localization and transcriptional activation ability assay revealed that LlbHLH12 was located in the nucleus without transcriptional activation activity. Overexpression of LlbHLH12 in Nicotiana tabacum and L. longituba inhibited anthocyanin accumulation by suppressing the expression of anthocyanin biosynthetic pathway genes. Furthermore, yeast one-hybrid, dual-luciferase, and β-glucuronidase activity assays showed that LlbHLH12 directly bound to the promoters of LlPAL and LlDFRc and suppressed their expression to inhibit anthocyanin biosynthesis. Overall, our study identified a novel bHLH repressor negatively regulating anthocyanin biosynthesis and provided new insights into the molecular mechanisms underlying color fading in L. longituba petals.
基金financial support of the National Natural Science Foundation of China(82370532,82341219)Shanghai Hospital Development Center Foundation(SHDC12022118)。
文摘YdjC chitooligosaccharide deacetylase homolog(YDJC)has been identified as a susceptibility gene for inflammatory bowel disease(IBD),yet its role in the pathogenesis of IBD,particularly in regulating immune responses in the gut mucosa,remains elusive.In this study,we demonstrated that YDJC expression is downregulated in inflamed mucosa,particularly in the CD4^(+)T cells of IBD patients,and that Ydjc deficiency promotes CD4^(+)T-cell proliferation and Th1 cell differentiation,thereby exacerbating acute and chronic colitis in mice.Integrative transcriptomic,proteomic,and metabolomic analyses revealed that Ydjc^(-/-)CD4^(+)T cells exhibit upregulated SREBP2-mediated cholesterol biosynthesis.Consistently,treatment with key enzyme inhibitors targeting cholesterol biosynthesis,including simvastatin,fatostatin,and AAV-sh-Srebf2,markedly suppressed CD4^(+)T-cell proliferation and Th1 cell differentiation,thereby alleviating colitis in Ydjc^(-/-)mice.Mechanistically,YDJC directly deacetylates SREBP2,which further suppresses downstream target gene expression(e.g.,Hmgcr,Hmgcs1,and Cyp51).Therefore,our findings elucidate a novel mechanism whereby YDJC restrains intestinal mucosal inflammation by downregulating SREBP2-driven Th1 cell differentiation,suggesting that targeting YDJC and SREBP2-mediated cholesterol biosynthesis may serve as promising therapeutic strategies for IBD.
文摘Artemisia annua L. produces small amounts of the sesquiterpenoid artemisinin, which is used for treatment of malaria. A worldwide shortage of the drug has led to intense research to increase the yield of artemisinin in the plant. In order to study the regulation of expression of a key enzyme of artemisinin biosynthesis, the promoter region of the key enzyme amorpha-4,11-diene synthase (ADS) was cloned and fused with the β-glucuronidase (GUS) reporter gene. Transgenic plants of A. annua expressing this fusion were generated and studied. Transgenic plants expressing the GUS gene were used to establish the activity of the cloned promoter by a GUS activity staining procedure. GUS under the control of the ADS promoter showed specific expression in glandular trichomes. The activity of the ADS promoter varies temporally and in old tissues essentially no GUS staining could be observed. The expression pattern of GUS and ADS in aerial parts of the transgenic plant was essentially the same indicating that the cis-elements controlling glandular trichome specific expression are included in the cloned promoter. However, some cis-element(s) that control expression in root and old leaf appears to be missing in the cloned promoter. Furthermore, qPCR was used to compare the activity of the wild-type ADS promoter with that of the cloned ADS promoter. The latter promoter showed a considerably lower activity than the wild-type promoter as judged from the levels of GUS and ADS transcripts, respectively, which may be due to the removal of an enhancing cis-element from the ADS promoter. The ADS gene is specifically expressed in stalk and secretory cells of glandular trichomes of A. annua.
基金the National Key Research and Development Program of China (2017YFD0300103)the National Natural Science Foundation of China (31571602, 31871566) for its financial support to this research project
文摘Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose content.We investigated the effect of SSI suppression on grain quality traits,starch biosynthesis,and amylopectin chain distribution in rice plants exposed to two different temperature regimes.The activities and transcripts of BEs,DBEs,and other SS isoforms were further investigated to clarify the effect of SSI suppression on these key enzymes and their specific isoforms under different temperature treatments.Suppression of SSI by RNAi altered grain starch component and amylopectin chain distribution,but it exerted only a slight effect on total starch content(%)and accumulation amount(mg kernel?1)and on starch granule morphology and particle size distribution.Under normal temperature(NT),insignificant differences in kernel weight,chalky kernel proportion,chalky degree,and starch granule morphology between SSI-RNAi line and its wild type(WT)were observed.However,amylose content(AC)level and granule-bound starch synthase(GBSS)activity in rice endosperms were markedly increased by SSI-RNAi suppression.The chalky kernel proportion and chalky degree of SSIRNAi lines were significantly higher than those of WT under high temperature(HT)exposure at filling stage.Inhibition of SSI by RNAi affected amylopectin chain distribution and raised starch gelatinization temperature(GT)in two ways:directly from the SSI deficiency itself and indirectly by reducing BEIIb amounts in an SSI-deficient background.The deficiency of SSI expression led to an alteration in the susceptibility of grain chalkiness occurrence and starch gelatinization temperature to HT exposure,owing to a pleiotropic effect of SSI deficiency on the expression of other genes associated with starch biosynthesis.
基金supported by the National Natural Science Foundation of China(Nos.81872933 and 81173119)the National Natural Science Foundation of China and Xinjiang Uygur Autonomous Region of China(No.U1130303)+1 种基金the Technology Cooperation Projects of Science in Shanghai,China(No.20015800100)the Key Project of Ministry of Science and Technology of China(No.2018ZX09731016-004)。
文摘Terpenoid indole(TIAs)andβ-carboline alkaloids(BCAs),such as suppressant reserpine,vasodilatory yohimbine,and antimalarial quinine,are natural compounds derived from strictosidine.These compounds can exert powerful pharmacological effects but be obtained from limited source in nature.the whole biosynthetic pathway of TIAs and BCAs,The Pictet–Spengler reaction catalyzed by strictosidine synthase(STR;EC:4.3.3.2)is the rate-limiting step.Therefore,it is necessary to investigate their biosynthesis pathways,especially the role of STR,and related findings will support the biosynthetic generation of natural and unnatural compounds.This review summarizes the latest studies concerning the function of STR in TIA and BCA biosynthesis,and illustrates the compounds derived from strictosidine.The substrate specificity of STR based on its structure is also summarized.Proteins that contain sixbladed four-strandedβ-propeller folds in many organisms,other than plants,are listed.The presence of these folds may lead to similar functions among organisms.The expression of STR gene can greatly influence the production of many compounds.STR is mainly applied to product various valuable drugs in plant cell suspension culture and biosynthesis in other carriers.
