Identification and Characterization of Chalcone Synthase Gene Family Members in Nicotiana tabacum

Journal of Plant Growth Regulation - Chalcone synthase (CHS, EC 2.3.1.74) is a member of the plant polyketide synthase superfamily; it catalyzes the first committed step in the flavonoid...     

石榴WRKY基因家族全基因组鉴定与表达分析

WRKY蛋白是一类在植物生长发育过程及生物与非生物胁迫过程中起重要调控作用的转录因子。该研究利用石榴全基因组数据,采用生物信息学的方法,对石榴WRKY转录因子家族成员蛋白理化性质、系统进化、基因结构、保守基序、顺式作用元件、蛋白互作及基因共表达和转录组表达模式进行系统分析。结果共鉴定出69个PgWRKY基因;分组鉴定和进化分析显示WRKY蛋白可分为Ⅰ、Ⅱ和Ⅲ共三大类型。顺式作用元件分析表明,PgWRKY基因广泛参与到非生物胁迫中;蛋白互作网络与共表达分析暗示PgWRKY基因在同一胁迫应答中可能作用一致并同时诱导表达;RNA-Seq数据分析表明,PgWRKY基因有一定的组织表达特异性,广泛参与植物营养、生殖生长以及根部逆境胁迫应答过程。     

Transcriptome-Wide Identification and Expression Profiles of Masson Pine WRKY Transcription Factors in Response to Low Phosphorus Stress

Plant Molecular Biology Reporter - Masson pine (Pinus massoniana Lamb.) is an economically important conifer tree that can be widely used for timber, pulp, and resin production. However, the...     

碎米荠超氧化物歧化酶基因家族成员的鉴定和分析

为了解碎米荠(Cardamine hirsuta)的SOD基因特征,对SOD家族成员的基因结构、染色体定位、系统进化关系进行了分析,对顺式作用元件和蛋白结构进行了预测,并利用qRT-PCR技术检测各家族成员的组织表达模式。结果表明,碎米荠基因组中共有10个SOD基因(ChSODs),包括6个Cu/Zn-SOD、3个Fe-SOD和1个Mn-SOD。编码的ChSODs蛋白有57~ 324个氨基酸,分子量为6 419.41~34 659.01 kDa,理论等电点为4.92~9.60;系统进化树分析表明,碎米荠的ChSOD与拟南芥的AtSOD的同源性较高;ChSODs在根、茎、叶中均有表达,且在叶中高表达,其中CARHR085500和CARHR256690在叶和茎中表达量较高;顺式作用元件预测表明,碎米荠SOD响应多种非生物胁迫,其中对ABA和低温胁迫较为敏感; ChSODs蛋白质的二级和三级结构具有差异性。这表明碎米荠SOD基因在抗氧化过程中发挥重要作用。     

陆地棉XTH基因家族全基因组鉴定及在纤维发育过程的表达分析

本研究从陆地棉TM-1基因组中鉴定出72个XTH家族基因,编码木葡聚糖内转糖苷酶/水解酶(XTH,xyloglucan endotransglycosylase/hydrolase),分别命名为Gh XTH01~Gh XTH72,分析了其基因结构、保守基序、系统进化、理化性质、亚细胞定位,并探究其在棉纤维发育不同时期的表达规律。结果表明,XTH家族基因分布在除At 07、Dt 07以外的24条棉花染色体上,根据系统发育树,将XTH家族基因分为3个亚组;XTH氨基酸序列有3个保守基序,保守性较强;多数XTH蛋白定位在细胞外。根据XTHs在纤维发育不同时期的表达量变化,将其分为4类。通过构建陆地棉与拟南芥XTH氨基酸序列进化树,推测Gh XTH15、Gh XTH28、Gh XTH36、Gh XTH49、Gh XTH59、Gh XTH62、Gh XTH63等基因在棉纤维发育过程中发挥重要作用。通过比较XTH家族基因在不同纤维品质陆地棉品种中的表达差异,推测在优质棉花品种中优势表达基因Gh XTH03、Gh XTH12、Gh XTH17、Gh XTH22、Gh XTH23、Gh XTH28、Gh XTH33、Gh XTH44、Gh XTH46、Gh XTH59等在纤维发育伸长过程中可能发挥着重要作用。上述结果为研究陆地棉XTH基因家族在棉纤维发育中的功能提供了参考依据。     

Identification of Members of the Dimocarpus Longan Flowering Locus T Gene Family with Divergent Functions in Flowering

Dimocarpus longan is a subtropical fruit crop whose year-round production relies on the application of KClO₃ to induce flowering; however, the mechanism by which this chemical causes flowering is yet unknown. To further characterize floral signaling in this species, we have isolated three longan FLOWERING LOCUS T (FT)-like genes and studied their activities by heterologous expression in Arabidopsis. Expression of two of these genes (DlFT2 and DlFT3) accelerates flowering, whereas expression of the third gene (DlFT1) causes delayed flowering and produced floral morphology defects. This anti-florigenic protein may be a member of a class of FT-like family involved in flowering time control in biennial and perennial species. Surprisingly, KClO₃ treatment also suppressed the expression of both DlFT2 and DlFT3 in a field trial.     

Identification of Members of the Family Enterobacteriaceae by the R-B System

The R-B system was evaluated in parallel with conventional bacteriological procedures for the identification of members of the family Enterobacteriaceae by using bacterial strains from a variety of clinical specimens and from stock cultures. The R-B tests found to be reliable were, in decreasing order, the reactions for phenylalanine deaminase, hydrogen sulfide, and indole, the production of gas from glucose, and the decarboxylation of ornithine. The reactions in the R-B system found to be unreliable were motility, the decarboxylation of lysine, and the fermentation of both glucose and lactose. In addition, the reactions of the R-B system were more difficult to read and interpret than those of the conventional system. On the basis of this evaluation, it was concluded that the R-B system is not an acceptable alternative to the conventional methods in the identification of the Enterobacteriaceae.     

Role of Conserved Residues of the WRKY Domain in the DNA-binding of Tobacco WRKY Family Proteins

Four cDNA clones of tobacco that could code for polypeptides with two WRKY domains were isolated. Among four NtWRKYs and other WRKY family proteins, sequence similarity was basically limited to the two WRKY domains. Glutathione S-transferase fusion proteins with the C-terminal WRKY domain of four NtWRKYs bound specifically to the W-box (TTGACC), and the N-terminal WRKY domain showed weaker binding activity with the W-box compared to the C-terminal domain. The DNA-binding activity of the WRKY domain was abolished by o-phenanthroline and this inhibition was recovered specifically by Zn²⁺. Substitution of the conserved cysteine and histidine residues of the plant-specific C₂H₂-type zinc finger-like motif in the WRKY domain abolished the DNA binding. In addition, mutations in the invariable WRKYGQK sequence at the N-terminal side of the zinc finger-like motif also significantly reduced the DNA-binding activity, suggesting that these residues are required for proper folding of the DNA-binding zinc finger.     

拟南芥GHMP基因家族成员的组织表达及生物信息学分析

利用生物信息学方法获得拟南芥全基因组中12个GHMP基因家族成员。通过实时定量PCR技术研究这12个基因在不同组织中的表达,结果显示它们具有组织表达特异性。构建了拟南芥中GHMP基因家族成员的系统进化树。启动子区调控元件分析表明,大多数GHMP成员包含有光响应、生物钟及其它逆境胁迫响应的相关元件,预测这些GHMP基因家族成员可能参与了植物的光信号、生物钟及相关的逆境胁迫信号转导途径。     

Quick Identification of the Members of the Glutamine Synthetase Gene Family from Sunflower by Simultaneous Amplification of cDNA with Degenerate Primers

A single degenerate glutamine synthetase (GS)-specific primer was used to amplify the 3′ end of cDNAs derived from different GS genes that are expressed in leaves and roots of sunflower (Helianthus annuus L. cv. Peredovic). Four types of GS cDNA (I, II, III and IV) were simultaneously amplified from leaves and five types (I, II, V, VI, VII) from roots with a minimum investment of time and experimental work. cDNAs II, III and IV encode chloroplastic isoforms as deduced by the presence of chloroplastic GS-specific features in their sequences. The rest of cDNAs codifies cytosolic isoforms. Using cDNA-specific probes and primers, homologous sequences to all GS cDNAs amplified from cv. Peredovic, except to cDNAs III and IV, were detected in the inbred line R41. This result strongly suggests that the three cDNAs for chloroplastic isoform are allelic sequences from the same locus, and since cDNA type IV contains sequences derived from cDNAs II and III, it indicates a recombinational origin. The results presented are consistent with the existence of a GS gene family in sunflower with at least five members. Four of them, named ggs1.1 to ggs1.4, codify for the cytosolic isoforms (cDNAs I, V, VI and VII). A fifth member, named ggs2, from which three allelic sequences (cDNAs II, III and IV) have been cloned, encodes the chloroplastic isoform. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evaluation of the Enterotube System for Identification of Members of the Family Enterobacteriaceae

The Enterotube system was evaluated, in parallel with conventional bacteriological procedures for the identification of members of the family Enterobacteriaceae, by using bacterial strains from a variety of clinical specimens and from stock cultures. Excellent agreement between the two test systems was obtained with the following reactions: hydrogen sulfide, indole, Simmons' citrate, glucose, and lactose. Agreement was not as good (<85%) with the urea, phenylalanine deaminase, and dulcitol reactions. The Enterotube lysine decarboxylase test was unsatisfactory. The Enterotube method will correctly identify strains of the family Enterobacteriaceae approximately 50% of the time; if identification only as Klebsiella-Enterobacter-Serratia group is needed, the method will be correct 85% of the time. On the basis of this evaluation, the Enterotube system appears to be both simple and rapid for the presumptive identification of these bacteria. Because of the limited usefulness of the lysine decarboxylase test, the results obtained by this test system are less reliable than those obtained by conventional methods.     

拟南芥Rab1家族基因的克隆和功能研究

Yptl蛋白是酵母唯一的Rab1 GTP酶,调控囊泡从内质网到高尔基体的运输.酵母温敏突变株 ASY01是一个Ypt1基因功能部分缺失菌株,在26℃可以正常生长,但在37℃不能生长.拟南芥有4个Rab1基因,分别是AtRab1A1、AtRab1B1、AtRab1B2、AtRab1C1.克隆了所有4个AtRab1基因,构建酵母表达载体,转化温敏突变型酵母ASY01.温度敏感性实验结果表明,所有转基因菌株在37℃都恢复正常生长.说明拟南芥4个Rab1基因都与酵母Ypt1基因功能互补,都具有调节囊泡从内质网到高尔基体运输的功能.     

WRKY转录因子功能研究进展

植物各种诱导型基因的表达主要受特定的转录因子在转录水平上的调控.转录因子结构和功能的研究近年来成为植物分子生物学、细胞分子生物学和分子遗传学研究领域的重要内容.WRKY转录因子在拟南芥中有74个成员,水稻中有100多个成员,在生物胁迫及非生物胁迫方面发挥着非常重要的作用.该文就近年来国内外关于WRKY转录因子家族的结构与起源进化和在植物损伤、衰老、发育及代谢等过程中参与的调控功能,以及在植物防御反应中对防御相关基因表达的调控及参与的植物激素类信号途径等方面的研究进展进行了综述,为全面解析WRKY转录因子家族的结构与功能提供了新的视点.