Biomimetic natural biomaterials for tissue engineering and regenerative medicine:new biosynthesis methods,recent advances,and emerging applications

Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative medicine.This paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future challenges.We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM.Moreover,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications.Finally,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.

OsFK1 encodes C-14 sterol reductase,which is involved in sterol biosynthesis and affects premature aging of leaves in rice

The enzyme C-14 sterol reductase is involved in biosynthesis of brassinosteroids(BR)and sterols,as well as plant development.OsFK1,a member of the sterol biosynthesis pathway located in the endoplasmic reticulum(ER),encodes C-14 sterol reductase.However,there is little research on the function of C-14 sterol reductase in rice.Compared with the wild type,an osfk1 mutant showed dwarf phenotype and premature aging in the second leaf during the trefoil stage,and abnormal development of leaf veins during the tillering stage.The osfk1 mutant showed signs of aberrant PCD,as evidenced by TUNEL staining.This suggested that high ROS buildup caused DNA damage and ROS-mediated cell death in the mutant.The osfk1 mutant also showed decreased chlorophyll content and aberrant chloroplast structure.Sequencing of the osfk1 mutant allele revealed a non-synonymous G to A mutation in the final intron,leading to early termination.Here,we identified the OsFK1 allele,cloned it by Mutmap sequencing,and verified it by complementation.HPLC-MS/MS assays demonstrated that the osfk1 mutation caused lower phytosterol levels.These findings showed that the OsFK1 allele encoding C-14 sterol reductase is involved in phytosterol biosynthesis and mediates normal development of rice plants.

Wetting alternating with partial drying during grain filling increases lysine biosynthesis in inferior rice grain

Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG.

Identification and Molecular Characterization of the Alkaloid Biosynthesis Gene Family in Dendrobium catenatum

As one of the main active components of Dendrobium catenatum, alkaloids have high medicinal value. The physicochemicalproperties, conserved domains and motifs, phylogenetic analysis, and cis-acting elements of the genefamily members in the alkaloid biosynthesis pathway of D. catenatum were analyzed by bioinformatics, and theexpression of the genes in different years and tissues was analyzed by qRT-PCR. There are 16 gene families,including 25 genes, in the D. catenatum alkaloid biosynthesis pathway. The analysis of conserved domains andmotifs showed that the types, quantities, and orders of domains and motifs were similar among members ofthe same family, but there were significant differences among families. Phylogenetic analysis indicated that thegene family members showed some evolutionary conservation. Cis-acting element analysis revealed that therewere a large number of light-responsive elements and MYB (v-myb avian myeloblastosis viral oncogene homolog)-related elements in these genes. qRT-PCR showed that expressions of gene family members involved in alkaloidsynthesis were different in different years and tissues of D. catenatum. This study provides a theoretical basisfor further exploration of the regulatory mechanisms of these genes in the alkaloid biosynthesis of D. catenatum.

The biosynthesis of alarm pheromone in the wheat aphid Rhopalosiphum padi is regulated by hormones via fatty acid metabolism

Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly understood.In this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF biosynthesis.Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar nymphs.Triglycerides provide the prerequisite material for EβF production and release.Based on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism.This is the first systemic study on the modulation of EβF production in aphids.The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.

Biosynthesis of Silver Nanoparticles with Clerodendron phlomoides Leave Extract:Particle Morphology,Antimicrobial Potential and Application

Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides leaves extract has been found to contain various phytochemicals,such as phenols,flavonoids,tannins,and alkaloids,which possess reducing and stabilizing properties that can aid the production of silver particles.In this paper,morphological and topographical analyses were performed on silver nanoparticles.The biosynthesized silver nanoparticles showed antimicrobial potential against wound pathogens.SEM and TEM micrographs revealed that the particles were sphere and nanosized,which makes them suitable for various biomedical applications.

有氧运动训练影响阿尔茨海默症小鼠海马Notch1、Caspase-3的表达

背景:β-淀粉样蛋白和Tau蛋白会对阿尔茨海默症患者的认知功能产生不良影响,研究发现Notch1及Caspase-3能够调控β-淀粉样蛋白和Tau蛋白的表达。Notch1及Caspase-3是否介导了有氧运动改善阿尔茨海默症患者认知能力的过程还不清楚,目前缺乏长期有氧运动影响阿尔茨海默症小鼠海马中Notch1及Caspase-3表达的研究。目的:观察长期有氧运动干预阿尔茨海默症小鼠的空间学习记忆情况及其海马中Notch1及Caspase-3的表达,探讨Notch1及Caspase-3对阿尔茨海默症小鼠的影响。方法:将3月龄野生型及APP/PS1双转基因阿尔茨海默症小鼠随机分为4组:野生对照组、野生运动组、阿尔茨海默症对照组、阿尔茨海默症运动组,每组20只。对照组小鼠不进行运动,运动组小鼠进行5个月的有氧运动干预。运动干预结束后,采用Morris水迷宫检测小鼠空间学习记忆能力;采用Real-timePCR、免疫荧光及Westernblot检测各组小鼠海马组织Aβ_(1-42)、Tau、Notch1及Caspase-3蛋白的表达。结果与结论:①阿尔茨海默症小鼠空间学习记忆能力显著差于野生组(P<0.05);运动组小鼠空间学习记忆能力显著优于对照组(P<0.05);②阿尔茨海默症对照组小鼠海马Aβ_(1-42)、Tau、Notch1及Caspase-3表达均显著高于野生对照组(P<0.05);阿尔茨海默症运动组小鼠海马Aβ_(1-42)、Tau、Notch1及Caspase-3表达显著低于阿尔茨海默症对照组(P<0.05);③提示:长期有氧运动干预能够改善阿尔茨海默症小鼠的空间学习记忆能力,而这可能与有氧运动降低阿尔茨海默症小鼠海马Notch1、Caspase-3、Aβ_(1-42)及Tau蛋白表达有关。

miR-421靶向调控Menin/Caspase-3影响抑郁症的机制

目的探讨miR-421影响抑郁症发生发展的作用机制。方法采取单次腹腔注射脂多糖(LPS)方法建立抑郁大鼠模型,采用糖水偏好度测试和旷场实验进行抑郁行为检测。通过miRNA微阵列芯片和RT-PCR分析miR-421在抑郁大鼠海马组织中的表达量,运用TargetScan数据库和mi RDB数据库进行预测miR-421的靶基因,采用双荧光素酶报告基因实验观察其与靶基因的结合情况,观察过表达和抑制miR-421对靶基因的影响,随后过表达和抑制靶基因,观察其对下游因子的影响,最终探究miR-421影响抑郁症的相关机制。结果miRNA微阵列芯片和RT-PCR检测表明miR-421在抑郁大鼠海马组织中呈高表达(P<0.001),抑制miR-421的表达可显著恢复抑郁大鼠的体重和运动能力(P<0.001)。TargetScan数据库预测得到Menin与miR-421存在结合靶点,双荧光素酶报告基因实验表明Menin与miR-421具有相互作用;当miR-421过表达时,Menin表达量会下调(P<0.001),相反,当抑制miR-421表达时,Menin表达量会上调(P<0.001)。qPCR检测提示,Menin下游因子Caspase-3、NF-κB在抑郁大鼠模型海马组织中的表达显著提高(P<0.001),IL-1β在抑郁大鼠模型海马组织中的表达明显提高(P<0.01),当抑制Menin表达时,Caspase-3、NF-κB、IL-1β表达量会升高(P<0.001),当过表达Menin时,Caspase-3、NF-κB、IL-1β表达量则降低(P<0.001)。结论抑制miR-421表达可升高Menin表达,降低Caspase-3含量,减少神经炎症反应,从而改善抑郁症状。

电针联合神经减压/地塞米松对面神经受损家兔面神经病变及神经生长因子、Caspase-3表达的影响

目的观察电针联合神经减压/地塞米松对面神经损伤家兔面神经病变及血清神经生长因子(NGF)水平、面神经纤维组织中Caspase-3蛋白表达的影响,探讨其作用机制。方法将120只健康家兔随机分为假手术组、假手术+西医组、假手术+中医组、假手术+中西医组、模型组、模型+西医组、模型+中医组、模型+中西医组,每组15只。除假手术各组外,其余组均制备面神经损伤模型。术后假手术组、模型组不给予干预,假手术+西医组和模型+西医组均每天给予地塞米松1 mg/kg肌肉注射及面神经减压,假手术+中医组和模型+中医组均每天给予电针治疗(每次30 min,连续电针5 d休息2 d为1个周期),假手术+中西医组和模型+中西医组均每天给予地塞米松肌肉注射、面神经减压及电针治疗,各组均干预至术后第21天。分别于术后第1,7,21天检测外周血中NGF水平,HE染色观察面神经病变情况,免疫组化法检测面神经组织中Caspase-3阳性表达情况。结果术后第1,7,21天,模型各组血清NGF水平均明显低于假手术各组(P均<0.05);模型+中西医组血清NGF水平均明显高于模型组、模型+西医组、模型+中医组(P均<0.05),模型+西医组、模型+中医组均明显高于模型组(P均<0.05),模型+西医组与模型+中医组比较差异均无统计学意义(P均>0.05)。术后第1天,模型各组的Caspase-3阳性表达强度评分均明显高于假手术各组(P均<0.05);模型各干预组术后第1,7,21天的Caspase-3阳性表达强度评分均明显高于相应假手术各干预组(P均<0.05);模型+中西医组术后第1天和第7天的Caspase-3阳性表达强度评分均明显低于同期模型组和模型+西医组(P均<0.05),与模型+中医组比较差异均无统计学意义(P均>0.05);模型各组间术后第21天的Caspase-3阳性表达强度评分比较差异均无统计学意义(P均>0.05)。结论电针联合神经减压/地塞米松有促进面神经损伤修复的作用,其机制可能与上调血清NGF水平、下调面神经组织中Caspase-3蛋白的表达有关。

细胞焦亡及其相关因子caspase-1和IL-1β与非小细胞肺癌

细胞焦亡是一种与炎症相关的程序性细胞死亡过程,其经半胱天冬氨酸蛋白酶-1(caspase-1)与促炎因子白细胞介素-1β(interleukin 1β,IL-1β)介导后发生,从而发挥促进或抑制非小细胞肺癌(non-small cell lung cancer,NSCLC)发生、发展的双重作用。一方面,焦亡相关因子通过构建促肿瘤微环境助力NSCLC进展;另一方面,caspase-1和IL-1β通过调控经典炎性细胞焦亡途径延缓NSCLC进展。在肺肿瘤治疗方面,尽管部分化学治疗、免疫治疗、靶向治疗及中草药治疗通过细胞焦亡分子调控机制增强了药物敏感性,使癌细胞的进展得到延缓,但同时周围正常组织也因细胞焦亡产生的不良反应而受到伤害。Caspase-1、IL-1β作为新的、独立的生物学标志物可通过诱导细胞焦亡的发生而参与NSCLC的发生,并能在NSCLC治疗中发挥作用,可为NSCLC靶向治疗提供新的理论依据和策略。

基于Caspase-3/Bcl-2/Bax信号通路探究加味旋覆代赭汤治疗食管癌前病变的作用机制

目的:探究加味旋覆代赭汤对食管癌前病变大鼠Caspase-3/Bcl-2/Bax信号通路的调控作用机制。方法:将48只雄性SD大鼠随机分为4组,空白组、模型组、中药组、西药组,每组各12只。除空白组外均采用复合造模法制作食管癌前病变大鼠模型,造模成功后,分别进行药物灌胃干预,空白组、模型组用生理盐水灌胃,中药组和西药组分别给予加味旋覆代赭汤、西药(雷贝拉唑+莫沙必利)灌胃,给药8周取材。利用光学显微镜观察食管上皮组织的形态学变化;分别应用蛋白质印迹法(Western-blot)及聚合酶链式反应(PCR)检测食管上皮组织Caspase-3、Bcl-2及Bax的表达水平。结果:与空白组比较,模型组大鼠食管上皮病理积分升高(P<0.01);与模型组比较,中药组、西药组大鼠食管上皮病理积分均降低(P<0.01)。PCR及Western-blot检测结果显示,与空白组比较,模型组大鼠Caspase-3、Bax mRNA、蛋白表达均降低(P<0.01);与模型组比较,中药、西药组大鼠Caspase-3、Bax mRNA、蛋白表达均增高(P<0.05)。与空白组比较,模型组大鼠食管组织中Bcl-2 m RNA及蛋白表达水平均升高(P<0.05);与模型组比较,中药组和西药组Bcl-2 mRNA及蛋白表达水平均降低(P<0.05)。结论:加味旋覆代赭汤可能通过下调Bcl-2/Bax比值,增加线粒体外膜通透性,释放凋亡因子,激活Caspase-3,使病变组织发生凋亡,扭转食管上皮异型增生,从而起到治疗食管癌前病变的作用。

非小细胞肺癌患者血清中Caspase-1与IL-1β的表达水平及临床相关性研究

目的探讨非小细胞肺癌(non-small cell lung cancer,NSCLC)患者血清中半胱天冬氨酸蛋白酶-1(Caspase protease-1,Caspase-1)与促炎因子白介素-1β(Interleukin1β,IL-1β)的表达水平与临床病理特征及诊断价值的关系。方法选取2022年9月至2023年9月就诊于该院符合纳排标准的NSCLC患者60例为研究组;同期选取30例健康人群为对照组。比较两组血清中Caspase-1、IL-1β的表达并分析其与NSCLC病理特征的相关性,P<0.05表示差异有统计学意义。结果研究组Caspase-1、IL-1β水平明显高于对照组(P<0.001)。肿瘤直径(cm)≥3、Ⅲ-Ⅳ期及淋巴结转移者的Caspase-1、IL-1β水平分别高于<3cm、Ⅰ-Ⅱ期及无淋巴结转移者;女性、右肺病变及远处转移者的IL-1β水平高于男性、左肺病变及无远处转移者(P<0.05)。二元Logistic回归分析示Caspase-1和IL-1β水平的升高是NSCLC发生的独立危险因素(P<0.001)。受试者工作特征(Receiver operating characteristics,ROC)曲线示Caspase-1、IL-1β、二者联合诊断NSCLC的ROC曲线下面积大小(AUC)及其95%CI分别为:0.903(0.836~0.969)、0.925(0.872~0.978)、0.981(0.956~1.000),敏感度分别为:95.0%、85.0%、90.0%,特异度分别为:73.3%、83.3%、96.7%;提示Caspase-1和IL-1β联合检测NSCLC效果最优(P<0.001)。结论血清Caspase-1、IL-1β在NSCLC中表达升高,与临床病理特征密切相关,是NSCLC发生的独立危险因素,二者联合检测对NSCLC的诊断价值更高,是潜在的NSCLC肿瘤标志物。

三黄连合剂通过NLRP3/ASC/Caspase-1通路对哮喘患儿气道炎症的机制研究

目的探讨三黄连合剂通过NOD样受体蛋白3(NOD-like receptor protein domain associated protein 3,NLRP3)/凋亡相关颗粒样蛋白(apoptosis-associated speck-like protein containing a CARD,ASC)/半胱氨酸天冬氨酸蛋白酶1(cysteine aspartic acid specific protease-1,Caspase-1)通路对哮喘患儿气道炎症的作用及机制。方法选取2021年1月—2023年10月就诊的90例哮喘患儿,采用数字表法随机分为观察组与对照组,各45例。观察2组哮喘患儿不良反应、1 s用力呼气容积(forced expiratory volume in the first second,FEV_(1)%)、最大呼气流量(peak expiratory flow,PEF)、用力肺活量(forced vital capacity,FVC)、白细胞介素-1β(interleukin-1β,IL-1β)及TNF-α(tumor necrosis factor-α,TNF-α)表达水平差异。结果观察组不良反应发生率为6.66%,对照组为11.11%,差异无统计学意义(P>0.05)。观察组总有效率为95.56%,高于对照组的80.00%(P<0.05)。治疗后FEV_(1)%、PEF、FVC、哮喘控制测试表(asthma control test,ACT)评分高于对照组(P<0.05)。治疗后观察组血清IL-1β、IL-6、IL-8、IL-17、IL-18水平低于对照组(P<0.05)。治疗后观察组患儿血清NLRP3、ASC、Caspase-1、IL-1β蛋白表达水平低于对照组(P<0.05)。结论三黄连合剂治疗能减轻哮喘患儿气道炎症反应,降低炎症因子水平,改善肺功能,减轻病情,提高疗效,其可能通过NLRP3/ASC/Caspase-1通路发挥作用。

血清AMPK-αmRNA、Caspase-6 mRNA水平对非酒精性脂肪肝疗效的预测价值及影响因素分析

目的 分析血清腺苷酸活化蛋白激酶-αmRNA(Adenosine monophosphate activated protein kinase α,AMPK-αmRNA)、半胱氨酸天冬氨酸蛋白酶-6(Cystein-asparate protease,caspase-6) mRNA水平对非酒精性脂肪肝(Non-alcoholic fatty liver disease,NAFLD)疗效的预测价值及影响因素。方法 选取2021年10月-2023年8月聊城市人民医院感染性疾病科收治的188例NAFLD患者为研究对象,治疗6个月后以甘油三酯(TG)降低≥20%和(或)总胆固醇(TC)降低≥10%判断为治疗有效,归入有效组,否则判断为治疗无效,归入无效组。所有患者治疗前后检测血清AMPK-αmRNA、Caspase-6 mRNA水平。收集NAFLD患者一般资料,分析NAFLD疗效的影响因素。绘制受试者工作特征(Receiver operating characteristic curve,ROC)曲线分析血清AMPK-αmRNA,Caspase-6 mRNA水平对NAFLD疗效的预测价值。结果 188例NAFLD患者治疗6个月脱落6例,有效随访182例,其中治疗有效126例(69.23%),纳入有效组,治疗无效56例(30.77%),纳入无效组。与本组治疗前比较,治疗6个月后患者血清AMPK-αmRNA水平升高,Caspase-6 mRNA水平降低,差异有统计学意义(P<0.05)。与无效组比较,有效组治疗前、治疗6个月血清AMPK-αmRNA水平升高,Caspase-6 mRNA水平降低,差异有统计学意义(P<0.05)。患有糖尿病,血清TC、TG、低密度脂蛋白胆固醇(Low-density lipoprotein,LDL-C)、谷丙转氨酶(Alanime aminotransferase,ALT)、谷草转氨酶(Aspartate aminotransferase,AST),Caspase-6 mRNA水平是NAFLD疗效的独立危险因素,治疗前血清AMPK-αmRNA水平是其独立保护因素(P<0.05)。建立Logistic回归模型:logit(P)=-29.182-0.867×AMPK-αmRNA+0.890×Caspase-6 mRNA+1.956×糖尿病+1.283×TG+0.982×TC+0.703×LDL-C+0.066×ALT+0.101×AST,拟合度较好。治疗前血清AMPK-αmRNA、Caspase-6 mRNA水平及Logistic回归模型预测NAFLD疗效的曲线下面积(Area under curve,AUC)值分别为0.757、0.717、0.816,Logistic回归模型的预测价值大于AMPK-αmRNA,Caspase-6 mRNA单独评估价值(Z=2.149,P=0.032;Z=2.879,P=0.004)。结论 患者是否患有糖尿病,血清TG、TC、LDL-C、ALT、AST、AMPK-αmRNA、Caspase-6 mRNA水平是NAFLD疗效的影响因素,检测血清AMPK-αmRNA、Caspase-6 mRNA水平对NAFLD疗效具有一定预测价值。

Systematic analysis of MYB transcription factors and the role of LuMYB216 in regulating anthocyanin biosynthesis in the flowers of flax(Linum usitatissimum L.)

Anthocyanin is an important pigment that affects plant color and nutritional quality.MYBs play an important role in plant anthocyanin synthesis and accumulation.However,the regulatory function of MYB transcription factors in anthocyanin synthesis in flax flowers is still unclear.In this study,402 MYB transcription factors were identified in the flax genome.These MYB members are unevenly distributed on 15 chromosomes.The R2R3-LuMYB members were divided into 32phylogenetic subfamilies.qRT-PCR analysis showed that seven R2R3-LuMYB genes in the adjacent subfamily of the evolutionary tree had similar expression patterns,among which Lu MYB216 was highly expressed in the petals of different colors.Moreover,gene editing of LuMYB216 in flax showed that the petal color,anther color and seed coat color of mutant plants were significantly lighter than those of wild-type plants,and the anthocyanin content of lumyb216 mutant plants was significantly reduced.Correlation analysis indicated that LuMYB216 was significantly positively correlated with the upstream regulator bHLH30.This study systematically analyzed the MYB gene family in flax,laying a foundation for studying the regulation of LuMYB216 in flax flower anthocyanin synthesis.

GA Associated Dwarf 5 encodes an ent-kaurenoic acid oxidase required for maize gibberellin biosynthesis and morphogenesis

Gibberellin(GA)functions in plant growth and development.However,genes involved in the biosynthesis and regulation of GA in crop plants are poorly understood.We isolated the mutant gad5-1(GAAssociated Dwarf 5),characterized by dwarfing,short internodes,and dark green and short leaves.Map-based gene cloning and allelic verification confirmed that ZmGAD5 encodes ent-kaurenoic acid oxidase(KAO),which catalyzes KA(ent-kaurenoic acid)to GA12 conversion during GA biosynthesis in maize.ZmGAD5 is localized to the endoplasmic reticulum and is present in multiple maize organs.In gad5-1,the expression of ZmGAD5 is severely reduced,and the levels of the direct substrate of KAO,KA,is increased,leading to a reduction in GA content.The abnormal phenotype of gad5-1 was restored by exogenous application of GA3.The biomass,plant height,and levels of GA12 and GA3 in transgenic Arabidopsis overexpressing ZmGAD5 were increased in comparison with the corresponding controls Col-0.These findings deepen our understanding of genes involved in GA biosynthesis,and could lead to the development of maize lines with improved architecture and higher planting-density tolerance.

Caspase家族与失神经支配骨骼肌萎缩的研究进展

Caspase家族是含半胱氨酸的天冬氨酸蛋白水解酶的简称,根据主要作用分类可分为炎症Caspases和凋亡Caspases。在失神经支配骨骼肌萎缩中Caspases已被证实通过多种途径促进肌细胞凋亡。近年来有研究发现失神经支配肌细胞萎缩中Caspase-1所主导的细胞焦亡途径被激活,这是既往研究未提及的新的探索方向。现对Caspase家族在失神经支配骨骼肌萎缩中的作用进行概述。

VabHLH137 promotes proanthocyanidin and anthocyanin biosynthesis and enhances resistance to Colletotrichum gloeosporioides in grapevine

Proanthocyanidins(PAs)and anthocyanins are involved in the response of plants to various environmental stresses.However,the mechanism behind defense-induced PA biosynthetic regulation is still not completely elucidated,also in grapevine.This study performed a transcriptome sequencing analysis of grape berries infected with Colletotrichum gloeosporioides to highlight the induction of the VabHLH137 factor from the basic helix-loop-helix(bHLH)XII subfamily by the fungus,which appeared to be significantly co-expressedwith PA-related genes.The functional analysis of VabHLH137 overexpression and knockdownin transgenic grape calli showed that it positively regulated PA and anthocyanin biosynthesis.Moreover,VabHLH137 overexpression in the grape calli significantly increased resistance to C.gloeosporioides.A yeast one-hybrid and electrophoretic mobility shift assay revealed that VabHLH137 directly bound to the VaLAR2 promoter,enhancing its activity and interacting with VaMYBPAR,a transcriptional activator of PA biosynthesis.Furthermore,transient experiments showed that although the VabHLH137+VaMYBPAR complex activated VaLAR2 expression,it failed to further enhance VaLAR2 expression compared to VaMYBPAR alone.The findings indicated that VabHLH137 enhanced PA biosynthesis by activating of VaLAR2 expression,providing new insight into the transcriptional regulation of defense-induced PA biosynthesis in grapevine.

Identification of key gene networks controlling monoterpene biosynthesis during grape ripening by integrating transcriptome and metabolite profiling

Monoterpenes are typical aroma components of muscat grape cultivars,providing pleasant floral and fruity aromas to grapes and wines.However,the molecular mechanism of monoterpene biosynthesis between muscat and non-muscat grape remains unclear.Here,the muscat grape cultivar‘Jumeigui’and the non-muscat grape cultivar‘Kyoho’were chosen as plant materials for a comprehensive transcriptome and metabolite analysis.The gas chromatography-mass spectrometry(GC-MS)analysis demonstrated that a total of 27 and 23 monoterpene compounds were identified and quantified in the‘Jumeigui’and‘Kyoho’grape,respectively.‘Jumeigui’grape accumulated significantly higher concentrations of monoterpenes than‘Kyoho’grape.Furthermore,geraniol,linalool,geranic acid,and β-citronellol might be important odorants contributing to the floral character of the‘Jumeigui’grape due to the high levels odor activity values(OAVs).Transcriptome analysis demonstrated that the expression profiles of VvDXS,VvGGPPS.SSU1,Vv TPS-b/g showed a positive correlation with monoterpene accumulation in grapes.In addition,the expression patterns of the genes involved in jasmonic acid(JA)synthesis and signal were also positively correlated with monoterpene accumulation.All these results will help guide the functional verification of candidate genes related to monoterpene biosynthesis,as well as identify the master transcriptional and hormonal regulators of this pathway in grapes.

The PcHY5 methylation is associated with anthocyanin biosynthesis and transport in ‘Max Red Bartlett' and ‘Bartlett' pears

The red coloring of pear fruits is mainly caused by anthocyanin accumulation. Red sport, represented by the green pear cultivar ‘Bartlett’(BL) and the red-skinned derivative ‘Max Red Bartlett’(MRB), is an ideal material for studying the molecular mechanism of anthocyanin accumulation in pear. Genetic analysis has previously revealed a quantitative trait locus(QTL) associated with red skin color in MRB. However, the key gene in the QTL and the associated regulatory mechanism remain unknown. In the present study, transcriptomic and methylomic analyses were performed using pear skin for comparisons between BL and MRB. These analyses revealed differential PcHY5 DNA methylation levels between the two cultivars;MRB had lower PcHY5 methylation than BL during fruit development, and PcHY5 was more highly expressed in MRB than in BL. These results indicated that PcHY5 is involved in the variations in skin color between BL and MRB. We further used dual luciferase assays to verify that PcHY5 activates the promoters of the anthocyanin biosynthesis and transport genes PcUFGT, PcGST, PcMYB10 and PcMYB114, confirming that PcHY5 not only regulates anthocyanin biosynthesis but also anthocyanin transport. Furthermore, we analyzed a key differentially methylated site between MRB and BL, and found that it was located in an intronic region of PcHY5. The lower methylation levels in this PcHY5 intron in MRB were associated with red fruit color during development, whereas the higher methylation levels at the same site in BL were associated with green fruit color. Based on the differential expression and methylation patterns in PcHY5 and gene functional verification, we hypothesize that PcHY5, which is regulated by methylation levels, affects anthocyanin biosynthesis and transport to cause the variations in skin color between BL and MRB.