巴西橡胶树橡胶生物合成关键基因REF,SRPP,HRT1和HRT2的表达分析

橡胶延长因子REF、小橡胶粒子蛋白SRPP、橡胶转移酶HRT1和HRT2是巴西橡胶树胶乳中的主要橡胶粒子蛋白,它们在橡胶生物合成中发挥重要作用,与橡胶树胶乳产量密切相关。为进一步探明REF、SRPP、HRT1和HRT2的基因表达与橡胶树胶乳产量之间的关系,以成龄未开割橡胶树无性系热研7-33-97胶乳为材料,通过实时荧光定量PCR的方法,对割胶伤害、外源乙烯利和茉莉酸刺激的处理条件下,橡胶树胶乳中的REF、SRPP、HRT1和HRT2的基因表达进行了分析。结果表明,随着割胶刀次的增加,REF基因在第4刀的表达量最高,而SRPP、HRT1和HRT2基因则在第6刀表达量达到最高;而在乙烯利和茉莉酸刺激处理下,REF、SRPP、HRT1和HRT2基因均在刺激8 h后表达量达到最高。因此,割胶(机械伤害)、外源乙烯利和茉莉酸刺激促进橡胶树产胶可能与它们提高橡胶生物合成相关橡胶粒子蛋白REF、SRPP、HRT1和HRT2的基因表达具有密切关系。     

茉莉酸甲酯对广藿香JA信号转导途径及倍半萜合成途径关键基因表达的影响

分析外源性茉莉酸甲酯对广藿香JA信号转导途径关键基因JAZ2、MYC2、COI1及倍半萜合成途径关键基因PTS、FPPS、SQLE表达的影响,为深入研究茉莉酸甲酯调控广藿香JA信号转导途径及倍半萜合成途径的分子机制奠定基础。该文分别用0.10和0.25 mmol·L~(-1)的MeJA喷施广藿香叶片,于处理后的0、2、6、12、24、48、72 h摘取叶片,运用实时荧光定量PCR对JAZ2、MYC2、COI1、PTS、FPPS、SQLE基因的表达量进行检测。结果表明:0.10和0.25 mmol·L~(-1)的MeJA对广藿香JA信号转导途径JAZ2、MYC2、COI1及倍半萜合成途径PTS、FPPS、SQLE基因表达均有不同程度的促进作用,其中对JAZ2基因表达影响最显著。0.10mmol·L~(-1)MeJA溶液处理2 h时,JAZ2表达量上调13.52倍; 0.25 mmol·L~(-1)MeJA溶液处理48 h时,JAZ2表达量上调19.09倍。JA信号转导途径关键基因JAZ2与倍半萜合成途径关键基因FPPS存在极显著正相关关系。综上结果表明MeJA溶液可诱导广藿香JAZ2、MYC2、COI1、PTS、FPPS、SQLE基因的表达,且不同浓度MeJA对基因表达有着不一样的影响; JAZ2是JA信号转导途径里响应MeJA诱导的主要基因,其可激活倍半萜合成途径FPPS基因的协同表达,进而影响广藿香醇等倍半萜合成。     

小鼠基因转录表达分析中内参基因的优选

目的 建立小鼠基因转录表达分析中内参基因的选择方法.方法 以C57BL/6J和C3H/HeJ两个品系3个不同组织及2个不同发育阶段为研究对象,应用反转录实时定量PCR技术,评价GAPDH(glyceraldehyde-3-phosphate dehydrogenase)、HPRTl(hypoxanthine phosphoribosyl transferase)、B2M(β2-microglobulin)、PPIA(peptidylprolyl isomerase A)、ACTB(Actin-beta)和18S rRNA(18S ribosomal RNA)等6个看家基因在下丘脑、垂体与卵巢中mRNA水平的表达稳定性.结果 GeNorm统计分析表明,GAPDH和HPRT1表达最为稳定,PPIA等次之,B2M在不同组织和发育阶段中都几乎无表达.结论 成功筛选到GAPDH和HPRT1两个稳定表达的看家基因,证实了小鼠基因表达转录分析中内参基因选择的必要性和可行性.     

朱红毛斑蛾实时荧光定量PCR内参基因的筛选

筛选朱红毛斑蛾Phauda flammans(Walker)在不同成虫组织、性别及发育阶段处理条件下稳定表达的内参基因,为进一步开展朱红毛斑蛾相关基因的定量研究提供参考.本研究以不同成虫组织(头、胸、腹、足、翅和触角)、不同成虫性别和不同发育阶段(卵、幼虫、蛹和成虫)为实验材料,对10个候选内参基因进行实时荧光定量PCR(qRT-PCR),并使用GeNorm、NormFinder和BestKeeper软件及RefFinder网站对候选内参基因的表达稳定性进行评价和综合分析.结果表明:在朱红毛斑蛾不同成虫组织基因定量研究中,TUB2＞GAPDH＞TUBJ＞AK＞EFlα＞ACTIN3＞TBP＞TUB3＞ACTIN2＞RPL32,建议以TUB2和GAPDH作为内参基因;在不同成虫性别基因定量研究中,TUB1＞EFlα＞ACTIN3＞RPL32＞ACTIN2＞TUB2＞AK＞GAPDH＞TUB3＞TBP,建议以 TUB1 和EFlα作为内参基因;在不同发育阶段基因定量研究中,ACTIN3＞TBP＞TUB1＞EFlα＞TUB3＞ACTIN2＞GAPDH＞RPL32＞TUB2＞AK,建议以ACTIN3和TBP作为内参基因.基于GeNorm分析,最佳内参基因使用数目为2个.     

桉蝙蛾幼虫实时荧光定量PCR内参基因的筛选

本研究通过筛选桉蝙蛾Endoclita signifer Walker幼虫不同龄期与不同体节中稳定表达的内参基因,为桉蝙蛾基因表达研究提供参考。通过实时荧光定量PCR技术测定5个候选内参基因（ACTIN、GAPDH、TUB、RIB、EF）在桉蝙蛾幼虫不同龄期（3龄、5龄、9龄、12龄）与不同体节（头部、胸部、腹部）及全样品（由所有样品组成）处理中的表达量,后利用GeNorm、NormFinder、BestKeeper对5个候选基因的稳定性进行评估,最后由RefFinder综合分析结果,选出最佳的内参基因。基于4种分析方法的评估可知,桉蝙蛾5龄和9龄幼虫的不同体节、不同龄期幼虫的头部和胸部中内参基因的最佳数目为2,而3龄和12龄幼虫的不同体节、不同龄期幼虫的腹部及全样本中内参基因的最佳数目为3。3龄、5龄、9龄和12龄幼虫的不同体节中可分别选择ACTIN+RIB+GAPDH、EF+RIB、GAPDH+EF和ACTIN+RIB+GAPDH作为最稳定的内参基因组合;EF+RIB、RIB+GAPDH和EF+GAPDH+ACTIN可分别作为不同龄期幼虫头部、胸部和腹部的最佳内参基因组合;综合考虑桉蝙蛾幼虫不同龄期与不同体节的影响时,可选择RIB、ACTIN和GAPDH作为内参基因。     

拟南芥转录因子bHLH17负调控茉莉素介导的抗性反应

植物激素茉莉素作为抗性信号调控植物对腐生性病原菌和昆虫的抗性, 作为发育信号调控植物根的生长、雄蕊发育、表皮毛形成和叶片衰老。茉莉素受体COI1识别茉莉素分子, 进而与JAZ蛋白互作并诱导其降解, 继而调控多种茉莉素反应。拟南芥(Arabidopsis thaliana) IIId亚组bHLH转录因子(bHLH3、bHLH13、bHLH14和bHLH17)是JAZ的一类靶蛋白。与野生型相比, IIId亚组bHLH转录因子的单突变体对灰霉菌和甜菜夜蛾的抗性无明显差异, 而四突变体对灰霉菌和甜菜夜蛾的抗性增强。该文通过高表达bHLH17并研究其对灰霉菌和甜菜夜蛾的抗性反应, 结果显示, 被灰霉菌侵染的bHLH17高表达植株较野生型表现出更严重的病症。取食bHLH17高表达植株叶片的甜菜夜蛾幼虫体重大于取食野生型叶片的幼虫体重。bHLH17高表达抑制了茉莉素诱导的抗性相关基因(Thi2.1)和伤害响应基因(VSP2、AOS、JAZ1、JAZ9和JAZ10)的表达。原生质体转化实验显示bHLH17通过其N端行使转录抑制功能。研究结果表明, IIId亚组bHLH转录抑制因子bHLH17高表达会负调控茉莉素介导的对灰霉菌和甜菜夜蛾的抗性。     

甘油醛-3-磷酸脱氢酶(GAPDH)作为内参的质疑以及在肿瘤中的表达

甘油醛-3-磷酸脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH/G3PDH)是经典的糖酵解酶,由于广泛存在于众多生物体中,几乎在所有组织中都高水平表达。长期以来认为,该酶在同种细胞或者组织中的蛋白质表达量一般是恒定的,被作为看家基因广泛用于RT-PCR、Western blot等实验操作的标准化的内参。然而,近年有文献从mRNA水平对GAPDH作为内参提出异议;也有比较同种组织在不同状态下的蛋白质表达差异时,GAPDH作为差异性蛋白质被鉴定。有研究认为在肿瘤组织或肿瘤细胞中GAPDH表达上调。本文就GAPDH作为内参的质疑以及在肿瘤中的表达和可能的机制作以阐述。     

翘嘴鳜per1 mRNA表达量分析中采用的内参基因稳定性比较

为筛选生物钟核心基因per1表达定量中的相对稳定性最好的内参基因,本研究取翘嘴鳜成鱼心脏、肝脏、肾脏、脑、红肌、白肌、肠、眼和脾等九个组织为研究对象,选取GAPDH、18S rRNA、β-actin、rps29、RPL13a、B2M和EF1a为内参基因,采用实时荧光定量PCR(qRT-PCR)对per1基因mRNA表达水平进行检测分析。研究结果表明18S rRNA和GAPDH的平均稳定值M最低,相对表达量最稳定。以18S rRNA和GAPDH为内参基因时分析发现per1基因表达量在肝脏中最高。本研究为在鱼类per1 mRNA表达检测过程中选用稳定的内参基因提供了实验和理论参考。     

玉米MYC基因家族的结构特点和表达模式分析

MYC属于bHLH转录因子家族中的一个亚族.本研究利用生物信息学的方法在玉米(Zea mays)基因组上共鉴定到8个玉米MYC转录因子,并对其理化性质、结构特点、保守结构域、系统进化和组织表达等进行分析.结果表明,玉米MYC理化性质差异较大,每个MYC蛋白均由位于N端的bHLH_MYC_N结构域,位于C端的bHLH结构域和一个亮氨酸拉链结构组成.基因结构分析显示,有4个ZmMYC基因只有1个外显子,其他4个ZmMYC基因包含有2～6个不等的内含子.多序列比对表明玉米MYC转录因子和小麦、水稻的MYC转录因子在保守结构域上具有较高的保守性.顺式作用元件显示在玉米ZmMYC基因的启动子区域存在和生长发育、胁迫应答相关的元件.组织表达模式分析表明玉米MYC基因具有组织表达特异性.本研究为进一步研究玉米MYC转录因子家族的生物学功能提供了科学依据.     

转录因子MYC2介导植物抗生物胁迫的研究进展

髓细胞组织增生蛋白(Myelocytomatosis proteins,MYC)类转录因子,是植物激素茉莉酸(JA)响应途径中的激活转录因子,广泛存在于动植物中,MYC2转录因子属于bHLH类转录因子家族,含有bHLH保守结构域,是当前MYC类转录因子中研究最透彻的一个。随着对植物抗生物逆境不断深入研究,对MYC2的研究亦逐渐清晰。本文综述了转录因子MYC2通过与下游靶基因形成一个层级转录级联,放大转录输出,参与调控植物抗生物逆境,着重阐述了水稻OsMYC2转录因子在抗生物逆境中的作用;茉莉酸ZIM结构域蛋白(Jasmonate ZIM-domain,JAZ)作为JA信号的转录抑制因子,抑制MYC2的活性并参与介导JA信号途径,为MYC2功能机制研究提供了参考,并对今后的研究热点与方向进行了展望。     

Ectopic Expression of Erigeron breviscapus JAZ1 Affects JA-Induced Development Processes in Transgenic Arabidopsis

The jasmonate ZIM-domain (JAZ) proteins are repressors that function in the regulation of plant growth, development, and response to stimulation of different signals in the JA signaling pathway. Erigeron breviscapus is characteristic of sporophyte self-incompatibility (SSI). However, whether JA signaling is involved in regulation of development processes in E. breviscapus is unclear. In this study, the JAZ homolog EbJAZ1 was isolated and characterized from E. breviscapus. EbJAZ1 was localized to the nucleus, and expressed in roots, stems, leaves and flowers. Ectopic expression of EbJAZ1 in Arabidopsis resulted in shorter filament and silique length, and lower seed fertility. In addition, MeJA-induced root growth inhibition was compromised in transgenic plants. Further qRT-PCR analysis indicated that expression patterns of marker genes for VSP1, VSP2, JAZ1, JAZ5, JAZ8, JAZ10, MYC2, and bHLH17 were downregulated in transgenic plants compared to wild-type, suggesting that EbJAZ regulates the development of flower organs, seed fertility, and primary root growth through the JA signaling pathway. Thus, our results indicate that EbJAZ1 is one of the important regulators possibly involved in SSI and other developmental processes in Erigeron breviscapus.

     

Removal of organic pollutants and analysis of MLSS–COD removal relationship at different HRTs in a submerged membrane bioreactor

In order to investigate the influence of hydraulic retention time (HRT) on organic pollutant removal in a submerged membrane bioreactor (SMBR), a laboratory-scale experiment was conducted using domestic sewage as influent. The dissolved oxygen (DO) concentration was controlled at 2.0– during the experimental period. The experiments demonstrated that when HRT was 3, 2 and 1 h, the reduction of chemical oxygen demand (COD) was 89.3–97.2, 88.5–97.3 and 80–91.1%, and the effluent COD was 38.9–11.2, 41.6–10.8 and 63.4–, respectively. It is suggested that an HRT of 1 h could meet the normal standard of discharged domestic sewage, and an HRT of 2 h could meet that of water reclamation. In addition, we use mathematical software MATLAB to analyse the relation of mixed liquor suspended solids (MLSS) and COD removal. The results showed that the optimum MLSS concentration should be maintained at around in the SMBR. The results also showed that the COD removal was related to HRT (τ), influent concentration (S₀) and sludge loading rate for COD removal (N_S). Moreover, the high COD removal could be achieved through adjusting τ, S₀ and N_S.     

甜荞FeFUL2基因的克隆与表达分析

为了探索甜荞FUL同源基因参与花与籽粒发育调控的分子机制,该文采用同源克隆的方法从甜荞(Fagopyrum esculentum)长花柱和长雄蕊突变体(lpls)中克隆到1个长837 bp的FeFUL2基因(GenBank登录号为MG779493.1),其包含长690 bp的完整开放阅读框,编码1个由229个氨基酸残基组成的MADS-box转录因子。通过对FeFUL2进行分子系统发生、同源蛋白比对与转录因子结构分析,结果显示FeFUL2与核心真双子叶植物AP1/FUL亚家族转录因子中的euFUL进化系聚于1个进化分支,属甜荞euFUL型MADS-box转录因子,且包含1个57个氨基酸残基长的高度保守的MADS结构域、1个69个氨基酸残基长的次级保守的K结构域,其C末端转录激活区在序列长度和氨基酸残基组成上与其他euFUL型转录因子差异较大,但仍含有2个euFUL型转录因子特有的保守基元:FUL motif和paleo AP1 motif。用qPCR检测基因表达的组织特异性显示:FeFUL2基因在甜荞lpls突变体的根、茎、叶、花被片、雄蕊、雌蕊和发育4 d的幼果中均有表达,但其在花被片中表达量极显著高于该基因在其他器官中的表达量(LSD,P0.01)。综合转录因子的结构与基因的表达模式推测,FeFUL2基因与其他euFUL型基因的功能可能存在一定差异,其在花发育过程中可能主要参与甜荞花被片的发育调控。     

Structural and transcriptional analysis of<Emphasis Type="Italic"> S</Emphasis>-locus F-box genes in<Emphasis Type="Italic"> Antirrhinum</Emphasis>

A class of ribonucleases termed S-RNases, which control the pistil expression of self-incompatibility, represents the only known functional products encoded by the S locus in species from the Solanaceae, Scrophulariaceae and Rosaceae. Previously, we identified a pollen-specific F-box gene, AhSLF (S locus F-box)-S₂, very similar to S₂-RNase in Antirrhinum, a member of the Scrophulariaceae. In addition, AhSLF-S₂ also detected the presence of its homologous DNA fragments. To identify these fragments, we constructed two genomic DNA libraries from Antirrhinum self-incompatible lines carrying alleles S₁S₅ and S₂S₄, respectively, using a transformation-competent artificial chromosome (TAC) vector. With AhSLF-S₂-specific primers, TAC clones containing both AhSLF-S₂ and its homologs were subsequently identified (S₂TAC, S₅TACa, S₄TAC, and S₁TACa). DNA blot hybridization, sequencing and segregation analyses revealed that they are organized as single allelic copies (AhSLF-S₂, -S₁, -S₄ and -S₅) tightly linked to the S-RNases. Furthermore, clusters of F-box genes similar to AhSLF-S₂ were identified. In total, three F-box genes (AhSLF-S₂, -S₂A and -S₂C) in S₂TAC (51 kb), three (AhSLF-S₄, -S₄A and -S₄D) in S₄TAC (75 kb), two (AhSLF-S₅ and -S₅A) in S₅TACa (55 kb), and two (AhSLF-S₁ and -S₁E) in S₁TACa (71 kb), respectively, were identified. Paralogous copies of these genes show 38–54% identity, with allelic copies sharing 90% amino acid identity. Among these genes, three (AhSLF-S₂C, -S₄D and -S₁E) were specifically expressed in pollen, similar to AhSLF-S₂, implying that they likely play important roles in pollen, whereas three AhSLF-SA alleles showed no detectable expression. In addition, several types of retroelements and transposons were identified in the sequenced regions, revealing some detailed information on the structural diversity of the S locus region. Taken together, these results indicate that both single allelic and tandemly duplicated genes are associated with the S locus in Antirrhinum. The implications of these findings in evolution and possible roles of allelic AhSLF-S genes in the self-incompatible reaction are discussed in species like Antirrhinum.Sequence data from this article have been deposited with the EMBL/GenBank databases under accession numbers AJ300474, AJ515534, AJ515536 and AJ515535     

Antifoulant diterpenes produced by the brown seaweed Canistrocarpus cervicornis

This paper reports the antifouling properties of the dichloromethane crude extract (DC) and 3 pure compounds isolated from the Brazilian brown seaweed Canistrocarpus cervicornis against establishment of the mussel Perna perna. DC extract showed a strong inhibition activity against byssal threads. Two natural dolastanes and one seco-dolastane diterpene, namely (4R, 9S, 14S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (1), (4R,7R,14S)-4α,7α-diacetoxy-14-hydroxydolast-1(15),8-diene (2) and isolinearol (3), were isolated from DC extract. Dolastane (1) inhibited 60% of byssal fixation, while compound 2 and the seco-dolastane (3) strongly inhibited (82%) the establishment of P. perna. This is the first report of this type of chemical skeleton in three powerful compounds that could be further explored for the development of antifouling technology.     

基于LC-MS代谢组学技术的丽豆-大豆差异代谢物比较研究

丽豆(Calophaca sinica)是我国华北地区特有的一种珍稀野生植物。为探明丽豆的营养价值，该文以大豆(Glycine max)为参照组，利用液相色谱-质谱联用(LC-MS)技术对其种子进行了比较代谢组学研究。结果表明：(1)丽豆和大豆中共检测到1 857种代谢产物，二者成分相同且含量相似的代谢物有1 698种(>90%),差异代谢物有159种(<10%)。(2)在差异代谢物中，成分差异的有9种，其中有5种为丽豆特有，剩余150种均为含量差异，其中48种(约30%)在丽豆中的含量高于大豆。(3) KEGG注释到8条差异代谢物显著富集(P<0.1)的通路，主要包括初生代谢物的各类氨基酸生物合成途径和次生代谢物的罗汉松脂素、花生四烯酸以及二萜类等生物合成途径。(4)丽豆比大豆含量低的化学组分主要是初生代谢产物，比大豆含量高的化学组分主要是次生代谢物，而这些次生代谢物在调节血糖、骨坏损修复、增强免疫以及消炎抗癌等生理过程中有着积极的作用。综上所述，该研究认为丽豆与大豆具有相近的营养价值，并且对改善人类亚健康状况有积极的影响；此外，该文使我们对丽豆的营养价值和代谢组成...