Identifying potential flavonoid biosynthesis regulator in Zanthoxylum bungeanum Maxim. by genome-wide characterization of the MYB transcription factor gene family

Plant MYB transcription factors(TFs) play crucial roles in regulating the biosynthesis of flavonoids but current analysis on their role in Zanthoxylum bungeanum Maxim.(ZBM) is far from comprehensive. In this study, we identified 270 MYB genes in ZBM and divided them into four subfamilies. The R2 R3-MYB(ZbMYB) category contained 251 genes and was classified into 33 subfamilies according to their phylogenetic results and sequence similarity. These subfamilies included 24 subgroups containing both MYBs of ZBM plants and AtMYBs, and nine subgroups containing only ZBM MYBs or AtMYBs. ZbMYBs with similar functions clustered into the same subgroup, indicating functional conservation. The subcellular localization analysis predicted that most ZbMYB genes were found in the nucleus. The transposed duplications appeared to play a major role in the expansion of the MYB gene family in ZBM. Through phylogenetic analysis and transcriptome profiling, it was found that 28 ZbMYB genes may regulate the biosynthesis of flavonoids in ZBM, and these genes expression presented distinct temporal and spatial expression patterns. In different fruit development stages of ZBM, the expression patterns of EVM0042160 and EVM0033809 genes obtained by qRT-PCR analysis are very similar to the flavonoid and anthocyanin content curves in ZBM. Further correlation analysis showed that the content of flavonoids in different fruit development stages and the transcript abundance levels of 28 ZbMYB genes have different degrees of correlation relationship. These results indicated that the ZbMYB genes might be involved in the flavonoid metabolic pathway. This comprehensive and systematic analysis of MYB family genes provided a solid foundation for further functional analysis of MYB TFs in ZBM.

Genome-wide identification and expression profiling of MYB transcription factor genes in radish(Raphanus sativus L.)

Radish(Raphanus sativus L.), an important root vegetable crop of the Brassicaceae family, has a high level of anthocyanin accumulation in its pigment root tissues. It was reported that MYB transcription factors(TFs) play vital roles in plant development and anthocyanin metabolism, and the PAP1/2 could promote expression of anthocyanin biosynthesis genes. In this study, a total of 187 radish MYB genes(Rs MYBs) were identified in the radish genome and clustered into 32 subfamilies. Among them, 159 Rs MYBs were localized on nine radish chromosomes. Interestingly, 14 Rs MYBs exhibited differential expression profiles in different taproot developmental stages among four differently colored radish lines. A number of Rs MYBs were highly expressed in the pigmented root tissues at the maturity stage, several genes including Rs MYB41, Rs MYB117, and Rs MYB132 being homologous to PAP1/2, showed high expression levels in the red skin of NAU-YH(red skin-white flesh) taproot, while Rs MYB65 and Rs MYB159 were highly expressed in the purple root skin of NAU-YZH(purple skin-red flesh), indicating that these Rs MYBs might positively regulate the process of anthocyanin accumulation in radish taproot. These results would provide valuable information for further functional characterization of Rs MYBs, and facilitate clarifying the molecular mechanism underlying anthocyanin biosynthesis in radish.

The R2R3-MYB transcription factor GaPC controls petal coloration in cotton

Although a few cases of genetic epistasis in plants have been reported, the combined analysis of genetically phenotypic segregation and the related molecular mechanism remains rarely studied. Here, we have identified a gene(named GaPC) controlling petal coloration in Gossypium arboreum and following a heritable recessive epistatic genetic model. Petal coloration is controlled by a single dominant gene,GaPC. A loss-of-function mutation of GaPC leads to a recessive gene Gapc that masks the phenotype of other color genes and shows recessive epistatic interactions. Map-based cloning showed that GaPC encodes an R2R3-MYB transcription factor. A 4814-bp long terminal repeat retrotransposon insertion at the second exon led to GaPC loss of function and disabled petal coloration. GaPC controlled petal coloration by regulating the anthocyanin and flavone biosynthesis pathways. Expression of core genes in the phenylpropanoid and anthocyanin pathways was higher in colored than in white petals. Petal color was conferred by flavonoids and anthocyanins, with red and yellow petals rich in anthocyanin and flavonol glycosides, respectively. This study provides new insight on molecular mechanism of recessive epistasis,also has potential breeding value by engineering GaPC to develop colored petals or fibers for multifunctional utilization of cotton.

Functional Characterization of SmbHLH13 in Anthocyanin Biosynthesis and Flowering in Eggplant

Anthocyanin is abundant in a few vegetables,including eggplant.It protects plants from abiotic stress and benefits human health,making the research of anthocyanin biosynthesis increasingly important.Flowering time is an important reference for judging reproduction and adaptability,which can guide plant production.In this study,SmbHLH13 from eggplant was identified.Yeast one-hybrid and dual-luciferase assays showed that SmbHLH13 binded and activated the expression of structural genes SmCHS and SmF3H in anthocyanin biosynthesis and it also was bound to the promoter of the key gene SmFT in flowering.Furthermore,genetic transformation of Arabidopsis revealed that overexpression of SmbHLH13 enhanced anthocyanin accumulation and delayed flowering.These results demonstrated that SmbHLH13 might promote anthocyanin accumulation through positive regulation of SmCHS and SmF3H.Moreover,SmbHLH13 might have a role in delaying eggplant flowering.

Genome-wide identification and analysis of AP2/ERF transcription factors related to camptothecin biosynthesis in Camptotheca acuminata

Camptotheca acuminata produces camptothecin(CPT),a monoterpene indole alkaloid(MIA)that is widely used in the treatment of lung,colorectal,cervical,and ovarian cancers.Its biosynthesis pathway has attracted significant attention,but the regulation of CPT biosynthesis by the APETALA2/ethylene-responsive factor(AP2/ERF)transcription factors(TFs)remains unclear.In this study,a systematic analysis of the AP2/ERF TFs family in C.acuminata was performed,including phylogeny,gene structure,conserved motifs,and gene expression profiles in different tissues and organs(immature bark,cotyledons,young flower,immature fruit,mature fruit,mature leaf,roots,upper stem,and lower stem)of C.acuminata.A total of 198 AP2/ERF genes were identified and divided into five relatively conserved subfamilies,including AP2(26 genes),DREB(61 genes),ERF(92 genes),RAV(18 genes),and Soloist(one gene).The combination of gene expression patterns in different C.acuminata tissues and organs,the phylogenetic tree,the co-expression analysis with biosynthetic genes,and the analysis of promoter sequences of key enzymes genes involved in CPT biosynthesis pathways revealed that eight AP2/ERF TFs in C.acuminata might be involved in CPT synthesis regulation,which exhibit relatively high expression levels in the upper stem or immature bark.Among these,four genes(Cac AP2/ERF123,Cac AP2/ERF125,Cac AP2/ERF126,and Cac AP2/ERF127)belong to the ERF–B2 subgroup;two genes(Cac AP2/ERF149 and Cac AP2/ERF152)belong to the ERF–B3 subgroup;and two more genes(Cac AP2/ERF095 and Cac AP2/ERF096)belong to the DREB–A6 subgroup.These results provide a foundation for future functional characterization of the AP2/ERF genes to enhance the biosynthesis of CPT compounds of C.acuminata.

A GATA-type transcription factor AcAREB for nitrogen metabolism is involved in regulation of cephalosporin biosynthesis in Acremonium chrysogenum

In filamentous fungi,nitrogen metabolism is repressed by GATA-type zinc finger transcription factors.Nitrogen metabolite repression has been found to affect antibiotic production,but the mechanism is still poorly understood.AcareB,encoding a homologue of fungal GATA-type regulatory protein,was cloned from Acremonium chrysogenum.Gene disruption and genetic complementation demonstrated that AcareB plays a key role in utilization of ammonium,glutamine and urea.In addition,significant reduction of cephalosporin production in the AcareB disruption mutant indicated that AcareB is important for cephalosporin production.In consistence with it,the transcriptional level of cephalosporin biosynthetic genes was significantly decreased in the AcareB disruption mutant.Electrophoretic mobility shift assay showed that AcAREB directly bound to the intergenic regions of pcbAB-pcbC,cefD1-cefD2 and cefEF-cefG.Sequence analysis showed that all the AcAREB binding sites contained the consensus GATA elements.AcareB is negatively autoregulated during cephalosporin production.Moreover,another GATA zinc-finger protein encoded by AcareA positively regulates the transcription of AcareB.However,AcareB does not regulate the transcription of AcareA.These results indicated that AcAREB plays an important role in both regulation of nitrogen metabolism and cephalosporin production in A.chrysogenum.

Arabidopsis transcription factor TCP4 represses chlorophyll biosynthesis to prevent petal greening

Green petals pose a challenge for pollinators to distinguish flowers from leaves,but they are valuable as a specialty flower trait.However,little is understood about the molecular mechanisms that underlie the development of green petals.Here,we report that CINCINNATA(CIN)-like TEOSINTE BRANCHED 1/CYCLOIDEA/PCF(TCP)proteins play key roles in the control of petal color.The septuple tcp2/3/4/5/10/13/17 mutant produced flowers with green petals due to chlorophyll accumulation.Expression of TCP4 complemented the petal phenotype of tcp2/3/4/5/10/13/17.We found that chloroplasts were converted into leucoplasts in the distal parts of wild-type petals but not in the proximal parts during flower development,whereas plastid conversion was compromised in the distal parts of tcp2/3/4/5/10/13/17 petals.TCP4 and most CIN-like TCPs were predominantly expressed in distal petal regions,consistent with the green–white pattern in wild-type petals and the petal greening observed in the distal parts of tcp2/3/4/5/10/13/17 petals.RNA-sequencing data revealed that most chlorophyll biosynthesis genes were downregulated in the white distal parts of wild-type petals,but these genes had elevated expression in the distal green parts of tcp2/3/4/5/10/13/17 petals and the green proximal parts of wild-type petals.We revealed that TCP4 repressed chlorophyll biosynthesis by directly binding to the promoters of PROTOCHLOROPHYLLIDE REDUCTASE(PORB),DIVINYL REDUCTASE(DVR),and SUPPRESSOR OF OVEREXPRESSION OF CO 1(SOC1),which are known to promote petal greening.We found that the conversion of chloroplasts to leucoplasts and the green coloration in the proximal parts of petals appeared to be conserved among plant species.Our findings uncover a major molecular mechanism that underpins the formation of petal color patterns and provide a foundation for the breeding of plants with green flowers.

Transcriptional regulation of artemisinin biosynthesis in Artemisia annua L.

Artemisinin, also known as qinghaosu, a sesquiterpene endoperoxide lactone isolated from the Chinese medicinal plant Artemisia annua L., is the most effective antimalarial drug which has saved millions of lives.Due to its great antimalarial activity and low content in wild A. annua plants, researches focused on enhancing the artemisin yield in plants became a hotspot. Several families of transcription factors have been reported to participate in regulating the biosynthesis and accumulation of artemisinin.In this review, we summarize recent investigations in these fields, with emphasis on newly identified transcription factors and their functions in artemisinin biosynthesis regulation, and provide new insight for further research.

Transcriptional regulation of oil biosynthesis inseed plants: Current understanding, applications,and perspectives

Plants produce and accumulate triacylglycerol(TAG)in their seeds as an energy reservoir to support the processes of seed germination and seedling development.Plant seed oils are vital not only for the human diet but also as renewable feedstocks for industrial use.TAG biosynthesis consists of two major steps:de novo fatty acid biosynthesis in the plastids and TAG assembly in the endoplasmic reticulum.The latest advances in unraveling transcriptional regulation have shed light on the molecular mechanisms of plant oil biosynthesis.We summarize recent progress in understanding the regulatory mechanisms of wellcharacterized and newly discovered transcription factors and other types of regulators that control plant fatty acid biosynthesis.The emerging picture shows that plant oil biosynthesis responds to developmental and environmental cues that stimulate a network of interacting transcriptional activators and repressors,which in turn fine-tune the spatiotemporal regulation of the pathway genes.

Wenshen Yangxue decoction(温肾养血方) promotes follicular development in aged female mice via stimulation of the silent information regulator 3/forkhead transcription factor O1 3a pathway

OBJECTIVE:To primarily explore the effect and mechanism of Wenshen Yangxue decoction(温肾养血方)in promoting follicular development in elderly female mice.METHODS:Fifty Institute of Cancer Research mice were randomly divided into blank,controlled ovarian hyperstimulation(COH),low-dose Wenshen Yangxue decoction,medium-dose Wenshen Yangxue decoction,and high-dose Wenshen Yangxue decoction groups,with 10 mice in each group.The number of ovulations,number of fertilizations,mitochondrial adenosine triphosphate(ATP)level,and mitochondrial DNA(mt DNA)of oocytes in each group were compared.Reverse transcriptionpolymerase chain reaction and Western blotting were used to detect the m RNA and protein expression levels of silent information regulator 3(Sirt3)and forkhead transcription factor O13a(FOXO3a).RESULTS:Wenshen Yangxue decoction significantly increased the number of ovulations in mice(P<0.05)and promoted the formation of fertilized eggs.The ATP level and mt DNA copy number of mice oocytes in the highdose groups were significantly higher than those in the COH group(P<0.05).Wenshen Yangxue decoction significantly increased the m RNA and protein levels of Sirt3 and FOXO3a in mouse oocytes.CONCLUSION:Wenshen Yangxue decoction promoted the development of follicles in elderly female mice,increased the number of ovulations and improved fertility.Its mechanism may be related to increased mitochondrial energy metabolism and regulation of the Sirt3/FOXO3a pathway.

A forkhead transcription factor contributes to the regulatory differences of pathogenicity in closely related fungal pathogens

Cryptococcus neoformans and its sister species Cryptococcus deuterogattii are important human fungal pathogens.Despite their phylogenetically close relationship,these two Cryptococcus pathogens are greatly different in their clinical characteristics.However,the determinants underlying the regulatory differences of their pathogenicity remain largely unknown.Here,we show that the forkhead transcription factor Hcm1 promotes infection in C.neoformans but not in C.deuterogattii.Monitoring in vitro and in vivo fitness outcomes of multiple clinical isolates from the two pathogens indicates that Hcm1 mediates pathogenicity in C.neoformans through its key involvement in oxidative stress defense.By comparison,Hcm1 is not critical for antioxidation in C.deuterogattii.Furthermore,we identified SRX1,which encodes the antioxidant sulfiredoxin,as a conserved target of Hcm1 in two Cryptococcus pathogens.Like HCM1,SRX1 had a greater role in antioxidation in C.neoformans than in C.deuterogattii.Significantly,overexpression of SRX1 can largely rescue the defective pathogenicity caused by the absence of Hcm1 in C.neoformans.Conversely,Srx1 is dispensable for virulence in C.deuterogattii.Overall,our findings demonstrate that the difference in the contribution of the antioxidant sulfiredoxin to oxidative stress defense underlies the Hcm1-mediated regulatory differences of pathogenicity in two closely related pathogens.

活动性肺结核患者血清ATG3和FOXO3水平变化对患者病情进展及预后评估的相关性分析

目的分析活动性肺结核患者血清中自噬相关基因3(ATG3)和叉头转录因子O亚型3(FOXO3)表达水平变化以及与患者病情进展及预后的关系。方法以2019年9月~2022年9月于本院就诊的91例活动性肺结核患者(观察组)为研究对象,另选取同时期于本院体检的91例健康体检者作为对照组;酶联免疫吸附法检测血清中ATG3和FOXO3表达水平;利用Spearman相关分析活动性肺结核患者血清中ATG3和FOXO3表达水平与患者病情严重程度之间的相关性;采用Logistic回归分析影响活动性肺结核患者预后的因素;采用ROC曲线分析血清中ATG3和FOXO3表达水平对活动性肺结核患者预后评估的价值。结果与对照组相比,观察组血清中ATG3和FOXO3表达水平显著下降(P<0.05);与轻症组相比,重症组患者血清中ATG3和FOXO3表达水平显著下降(P<0.05);与预后不良组相比,预后良好组患者血清中ATG3和FOXO3表达水平显著升高(P<0.05);预后良好组与预后不良组患者ESR、PCT、CRP、TNF-α、INF-γ和IL-2相比差异具有统计学意义(P<0.05);Spearman相关分析显示活动性肺结核患者血清中ATG3和FOXO3表达水平与患者病情严重程度呈负相关(P<0.05);Logistic回归分析结果显示,ESR、CRP、ATG3和FOXO3为影响活动性肺结核患者预后不良的因素(P<0.05);ROC曲线分析显示,血清中ATG3和FOXO3表达水平联合预测活动性肺结核患者预后较ATG3和FOXO3单一指标预测效果更优(P<0.05)。结论活动性肺结核患者血清中ATG3和FOXO3表达水平显著下降,且与活动性肺结核病情严重程度相关,二者联合对活动性肺结核患者预后具有较高的评估价值。

YTH结构域家族蛋白2和叉头蛋白转录因子3在肺腺癌中的表达关系研究

目的 分析YTH结构域家族蛋白2(YTHDF2)及叉头蛋白转录因子3(FOXO3)在肺腺癌病人中的表达及与预后的关系。方法 收集2020年1月至2021年5月在郑州大学第一附属医院行手术治疗的肺腺癌病人癌组织及对应的癌旁组织(距离癌组织5 cm以上)80对,收集病人临床病理资料;利用癌症基因组图谱(TCGA)数据库查询YTHDF2、FOXO3基因在肺腺癌中的表达水平;采用免疫组织化学法检测YTHDF2、FOXO3蛋白在肺腺癌组织中的表达情况;分析YTHDF2、FOXO3蛋白水平与肺腺癌病人临床病理资料的关系;分析肺腺癌中YTHDF2与FOXO3基因表达水平的相关性;对病人进行为期3年的随访,分析病人3年累积生存率。结果 YTHDF2、FOXO3蛋白在肺腺癌组织中的高表达率分别为34.00%、26.00%,明显低于癌旁正常组织中79.48%、61.54%(P<0.05)。YTHDF2蛋白表达情况与肺腺癌病人年龄、淋巴结转移和分化程度相关(P<0.05);与TNM分期、性别无关(P>0.05);FOXO3蛋白表达情况与肺腺癌病人性别和分化程度相关(P<0.05);肺腺癌组织中YTHDF2蛋白高表达组和低表达组病人3年累积生存率分别为53.30%、14.00%,经log-rank比较,差异有统计学意义(P<0.05);FOXO3蛋白高表达组和低表达组病人3年累积生存率分别为64.50%、12.20%,经Log-Rank比较,差异有统计学意义(P<0.05)。结论 YTHDF2、FOXO3在肺腺癌组织中均低表达,与病人肿瘤分化程度及3年累积生存率有关,有望成为评估肺腺癌病人预后的生物标志物。

植物类黄酮的分类、药理活性及其生物合成调控研究进展

类黄酮是植物中重要的次生代谢产物之一,包括黄酮、黄酮醇、异黄酮、黄烷酮、黄烷醇、查尔酮、花青素和原花青素等,在植物生长发育和逆境胁迫响应过程中发挥重要作用,同时具有抗氧化、抗衰老、抗菌消炎等药理活性。植物类黄酮的生物合成主要受两类基因控制,一类是直接编码类黄酮合成相关生物酶的结构基因,另一类是调控这些结构基因表达的转录因子。本文对植物类黄酮的种类、药理活性及其生物合成调控研究进展进行了综述,并探讨了今后的研究趋势,以期为植物类黄酮的研究和开发应用提供科学依据。

联合检测外周血TIRAP、FOXO3a、HBP预测脓毒症患者近期预后的价值及意义

目的探讨联合检测外周血TOLL/白介素-1受体相关蛋白(TIRAP)、叉头蛋白转录因子3a(FOXO3a)、肝素结合蛋白(HBP)对脓毒症患者近期预后的预测价值。方法回顾性收集2020年1月—2022年12月本院205例脓毒症患者的临床资料,根据28 d生存情况分为生存组157例、死亡组48例。统计两组外周血TIRAP、FOXO3a、HBP及急性生理功能和慢性健康状况评分系统Ⅱ(APACHEⅡ)、序贯器官衰竭评估(SOFA)评分。分析TIRAP、FOXO3a、HBP与APACHEⅡ、SOFA评分的相关性。采用Logistic回归方程分析TIRAP、FOXO3a、HBP交互作用对脓毒症近期预后的影响。评价TIRAP、FOXO3a、HBP联合预测脓毒症近期预后的价值。结果死亡组入院第1、3、7天外周血TIRAP、HBP水平及APACHEⅡ、SOFA评分高于生存组,FOXO3a水平低于生存组(P<0.05);入院第1天,脓毒症死亡患者TIRAP、HBP水平与APACHEⅡ、SOFA评分呈正相关,FOXO3a与APACHEⅡ、SOFA评分呈负相关(P<0.05);TIRAP×FOXO3a×HBP在脓毒症近期预后中存在交互作用(P<0.05);入院第1天外周血TIRAP+FOXO3a+HBP联合预测预后的曲线下面积(AUC)大于TIRAP+FOXO3a、TIRAP+HBP、FOXO3a+HBP,预测效能更佳(P<0.05)。结论脓毒症预后不良患者外周血TIRAP、HBP水平升高,FOXO3a水平降低,其水平变化与病情严重程度、近期预后有关,联合检测其水平可提高近期预后的预测效能。

血清FOXO3a、NLRP3、sICAM-1水平在冠心病合并高尿酸血症患者中的意义

目的探讨冠心病合并高尿酸血症(HUA)患者叉头转录因子O亚家族成员3a(FOXO3a)、核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、可溶性细胞间黏附分子1(sICAM-1)水平变化的意义。方法选取河南科技大学第一附属医院2021年1月至2022年8月收治的156例冠心病患者为研究对象,根据尿酸水平分为HUA组(62例)和UA正常组(94例)。比较两组一般临床资料及FOXO3a、NLRP3、sICAM-1水平,分析FOXO3a、NLRP3、sICAM-1水平与临床资料中有统计学差异指标及UA水平相关性,采用logistic回归分析影响冠心病合并HUA的危险因素,以受试者工作特征(ROC)曲线分析FOXO3a、NLRP3、sICAM-1水平联合检测对冠心病合并HUA的诊断价值。结果HUA组总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)水平高于UA正常组(P<0.05);HUA组FOXO3a、NLRP3、sICAM-1水平高于UA正常组(P<0.05);相关性分析发现,FOXO3a、NLRP3、sICAM-1水平与TC、TG、LDL-C、UA水平均呈正相关(P<0.05);logistic回归分析发现,TC(>5.04 mmol·L^(-1))、TG(>1.88 mmol·L^(-1))、LDL-C(>2.53 mmol·L^(-1))、FOXO3a(>4.65μg·L^(-1))、sICAM-1(>195.73μg·L^(-1))、NLRP3(>1322.12 ng·L^(-1))水平是冠心病患者合并HUA的危险因素(P<0.05);ROC分析发现,FOXO3a、sICAM-1、NLRP3水平联合诊断冠心病合并HUA的曲线下面积(AUC)为0.811,敏感度、特异度分别为95.16%、67.02%,优于各指标单一指标诊断,具有较高诊断效能(P<0.05)。结论FOXO3a、NLRP3、sICAM-1参与冠心病合并HUA发生过程,且在临床诊断冠心病合并HUA方面具有较高效能。

绿原酸生物合成调控及其应用研究进展

绿原酸(chlorogenic acid,CGA)是一类重要的酚酸类次生代谢物质,广泛存在于植物界中。绿原酸在植物的生长发育、抵御生物与非生物胁迫等方面扮演着重要的角色。另外,它还具有多种生物活性和药理功能,在抗炎、抗菌和降血糖等方面具有重要的应用潜力。然而,植物中绿原酸的含量通常很低,严重制约着其开发利用价值。因此,如何有效提高植物体中绿原酸的含量显得尤为重要。近年来,众多研究者通过基因工程、逆境胁迫及激素处理等手段在提高植株体内绿原酸含量方面取得了重要进展。在此基础上,研究者们对绿原酸的生物合成及其分子机制研究也开启了新的探索,以期为提高植物中体内绿原酸含量提供新的思路。鉴于此,本文对绿原酸的结构与功能、生物合成以及调控等相关研究进展进行了综述,系统分析了绿原酸合成途径中关键限速酶如苯丙氨酸解氨酶(phenylalanine ammonialyase,PAL)、肉桂酸-4-羟化酶(cinnamic acid 4-hydroxylase,C4H)和4-香豆酸-辅酶A连接酶(4-coumarate-CoA ligase,4CL)等对绿原酸合成的影响;并进一步阐述了MYB、WRKY和bHLH等转录因子调控绿原酸生物合成的作用机制。与此同时,系统归纳总结了生物胁迫、非生物胁迫、植物激素以及光质和光周期等外源因素对植株体内绿原酸含量及其合成调控的影响,并介绍了绿原酸在改善动物健康和人体健康中的作用机理。最后,对绿原酸研究中尚未解决的问题和未来研究方向进行了分析和展望,旨在为绿原酸的合理开发利用以及提高作物抗逆性方面提供有益的参考。

‘红满堂’苹果MbbZIP43基因的克隆与功能研究

【目的】为探究碱性亮氨酸拉链(bZIP)转录因子在‘红满堂’苹果花青素代谢中的调控作用。【方法】从‘红满堂’苹果克隆得到一个bZIP基因,分析了其基因及编码蛋白序列特性,利用洋葱表皮细胞瞬时转化确定其编码蛋白亚细胞定位,利用实时荧光定量PCR(RT-qPCR)研究了该基因在不同成熟时期‘红满堂’果实中的表达情况,基于烟草叶片、苹果叶片以及苹果果实瞬时转化研究了其对花青素积累和花青素合成相关结构基因表达的调控作用。【结果】该基因不含内含子,与MdbZIP43(XP_008393381.1)相似度最高,故命名为MbbZIP43。其编码序列长为522 bp,可编码由173 aa组成、含有bZIP_plant_GBF1结构域、定位于细胞核的亲水蛋白。RT-qPCR分析结果显示,随着果实成熟,MbbZIP43在‘红满堂’果实中的表达水平呈“先升后降”的变化趋势,在花后11周的果实中表达量最高。相关性分析显示MbbZIP43基因表达量与总黄酮和花青素含量正相关。瞬时过表达该基因的烟草叶片、苹果叶片和果皮中花青素含量分别提高了17.42%、25.66%和48.99%,过表达MbbZIP43的苹果叶片中花青素合成结构基因CHI、F3'H、DFR和UFGT分别提高了2.27倍、1.84倍、2.39倍和2.89倍;过表达MbbZIP43的苹果果皮中CHI、F3'H、DFR和UFGT分别提高了1.79倍、1.70倍、1.35倍和1.51倍,说明MbbZIP43可以通过上调这些结构基因的表达正调控苹果花青素合成。【结论】MbbZIP43可通过激活花青素合成相关结构基因CHI和UFGT等的表达进而促进花青素的积累。

滋阴明目方通过Akt/FoxO1/FasL通路抑制感光细胞凋亡治疗视网膜色素变性的机制研究

目的观察滋阴明目方对视网膜色素变性(retinitis pigmentosa,RP)小鼠视网膜组织中磷酸化蛋白激酶B(phosphorylated protein kinase B,p-Akt)、叉头框蛋白1(forkhead box transcription factor O1,FoxO1)以及凋亡相关因子配体(Fas ligand,FasL)表达的影响,探讨滋阴明目方抑制感光细胞凋亡的机制。方法将60只rd10小鼠随机分为模型组、滋阴明目方低剂量组[10 g/(kg·d)]、滋阴明目方中剂量组[20 g/(kg·d)]、滋阴明目方高剂量组[40 g/(kg·d)]、维生素A组[5 g/(kg·d)],每组12只;选取12只C57小鼠作为空白对照组(等量生理盐水),每组连续干预28 d。通过眼底照相观察小鼠眼底形态改变;进行视网膜电图检查并记录A波和B波振幅;HE染色观察病理形态学变化并测定外核层厚度;Western blot法检测小鼠视网膜组织p-Akt、FoxO1、FasL、半胱氨酸天冬氨酸特异性蛋白(cysteine aspartate-specific protease,Caspase)-3和Caspase-8蛋白表达。结果与空白对照组比较,模型组小鼠视盘苍白、变形,血管萎缩,视网膜电图的A波与B波振幅均降低(P<0.01),视网膜结构模糊,各层界限不清,感光细胞大量丧失,外核层明显变薄(P<0.01),视网膜组织中p-Akt蛋白表达水平明显降低(P<0.01),FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显升高(P<0.01)。与模型组比较,滋阴明目方中、高剂量组及维生素A组小鼠眼底血管较清晰,无视盘苍白表现;视网膜各层结构清晰,细胞排列相对整齐。与模型组、滋阴明目方低剂量组比较,滋阴明目方中、高剂量组的A波与B波振幅、视网膜外核层厚度均明显升高(P<0.01),维生素A组的B波振幅、视网膜外核层厚度明显升高(P<0.01);与滋阴明目方中剂量组比较,滋阴明目方高剂量组的A波与B波振幅、视网膜外核层厚度均明显升高(P<0.01),维生素A组的A波与B波振幅均明显降低(P<0.01);与滋阴明目方高剂量组比较,维生素A组的A波与B波振幅、视网膜外核层厚度均明显降低(P<0.01)。与模型组比较,滋阴明目方低、中、高剂量组和维生素A组p-Akt蛋白表达水平明显升高(P<0.01),FoxO1、FasL和Caspase-3蛋白表达水平降低(P<0.05,P<0.01),滋阴明目方中、高剂量组Caspase-8蛋白表达水平明显降低(P<0.01)。与滋阴明目方低剂量组比较,滋阴明目方高剂量组和维生素A组p-Akt蛋白表达水平明显升高(P<0.01),滋阴明目方中、高剂量组FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显降低(P<0.01)。与滋阴明目方中剂量组比较,滋阴明目方高剂量组和维生素A组p-Akt蛋白表达水平明显升高(P<0.01),滋阴明目方高剂量组FoxO1、Caspase-3和Caspase-8蛋白表达水平明显降低(P<0.01),维生素A组FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显升高(P<0.01)。与滋阴明目方高剂量组比较,维生素A组p-Akt蛋白表达水平明显降低(P<0.01),FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显升高(P<0.01)。结论滋阴明目方可能通过调控Akt/FoxO1/FasL通路,增强p-Akt表达,抑制FoxO1及下游基因FasL、Caspase-3和Caspase-8的蛋白表达,从而减少rd10小鼠视网膜细胞的凋亡,保护视网膜结构和功能,延缓RP的进展。

百合花香物质合成与调控机制研究进展

百合(Lilium spp.)原产于我国,在我国花卉产业中有着重要而特殊的地位。花香是其观赏性状的重要标签,已有研究结果表明,不同香型的百合主要花香成分差异较大,浓香型与淡香型百合的差异主要集中在萜烯类物质的不同,而采样时期、部位、环境、激素等均会导致花香成分变化。目前百合花香物质合成通路研究集中在萜烯合成通路上,多为萜烯合酶的功能研究及上游调控网络解析,而其他花香成分代谢途径基因的功能解析及分子调控机制的研究仍存在许多未解之谜。由于对百合花香合成及调控机制的解析不够全面与深入,难以支撑花香的精准改造,导致百合花香育种进程缓慢。深入挖掘与利用百合花香基因、完善相关代谢途径及调控网络可能会是百合花香的下一步研究重点。本文对百合花香的前期研究进行了回顾和总结,并对后期的研究方向提出展望,以期为后续百合花香分子调控机制研究提供参考,对定向培育香气怡人的百合新品种提供借鉴。