马槟榔甜蛋白基因（MBL11）的剪切重组和结构分析

马槟榔甜蛋白（mabinlin II）是我国所特有且唯一的植物甜蛋白,在体外至今没有得到具有甜味的基因表达产物。本文采用基因工程手段对基因进行剪切重组,将重组基因构建成植物表达载体转入拟南芥中,通过RT-．PCR检测导入基因的表达,同时采用生物信息学方法对MBL II基因及其重组基因进行分析和甜味检测显示,转基因拟南芥不具有明显的甜味,但RT-PCR的结果显示,MBL II基因及其重组基因可在转基因的拟南芥中表达。根据生物信息学方法分析结果推测,导入拟南芥中的重组马槟榔甜蛋白可能是具有甜味的蛋白。     

海藻糖在植物遗传转化中的应用

文章介绍海藻糖的性质、生理生化功能和海藻糖合酶基因在植物遗传转化中的应用。     

Cloning and molecular characterization of fructose-1,6-bisphosphate aldolase gene regulated by high-salinity and drought in Sesuvium portulacastrum

Sesuvium portulacastrum, a mangrove plant from seashore, is a halophyte species well adapted to salinity and drought. Some efforts have been made to describe its physiological and structural characteristics on salt and drought-tolerance, but the underlying molecular mechanism and key components have not yet been identified. Here, a fructose-1,6-bisphosphate aldolase gene, designated SpFBA, was isolated and characterized from S. portulacastrum roots in response to seawater. The SpFBA cDNA has a total length of 1452 bp with an open reading frame of 1071 bp, and is predicted to encode a precursor protein of 357 amino acid residues sharing high degree of homology with class I FBAs from other plants. Semi-quantitative RT-PCR analysis indicated that the SpFBA was more strongly expressed in roots than in leaves and stems, and the abiotic stimuli such as Seawater, NaCl, ABA, and PEG, could trigger a significant induction of SpFBA in S. portulacastrum roots within 2–12 h. Overproduction of Recombinant SpFBA resulted in an increased tolerance to salinity in transgenic Escherichia coli. All these results suggest that the SpFBA plays very important roles in responding to salt stress and related abiotic stimuli, and in improving the survival ability of S. portulacastrum under high salinity and drought. The GenBank Accession number of S. portulacastrum fructose-1,6-bisphosphate aldolase (SpFBA) is ACG68894.     

Characterization of 31 EST-derived microsatellite markers for the pearl oyster Pinctada martensii (Dunker)

We developed and characterized 31 microsatellite markers from expressed sequence tags of Pinctada martensii (Dunker). The number of alleles per locus ranged from 4 to 18 as determined in 44 individuals from a wild population. The expected heterozygosity ranged from 0.4121 to 0.9436, while the observed heterozygosity ranged from 0.4054 to 0.7273. Most of the loci are in Hardy-Weinberg equilibrium. These markers should be useful for population genetics studies, parentage and genome mapping in this species.     

用E．coli表达Canstatin—N及其表达条件优化

以重组质粒DET—CN为模板设计引物CASN1N和CASN2,PCR方法扩增约267bp的人血管能抑素N端1～89氨基酸基因片段,用EcoRI和Sal I双酶切将其克隆进pET-22b（＋）载体获得重组表达质粒pET-22b（＋）一CN,转化E．coliBL21（DE3）,用IPTG诱导表达Canstatin-N,产物以包涵体形式存在。本文在摇瓶发酵条件下研究了诱导剂浓度、诱导培养时间对目标蛋白表达的影响,结果表明IPTG的最佳诱导浓度为0．1mmol／L;37℃下诱导培养2h时产物表达量最高。纯化获得的融合hiS6的重组Canstatin—N具有免疫和抑制鸡胚绒毛尿囊膜（CAM）新生血管生成活性。     

Embryo and anther regulation of the mabinlin II sweet protein gene in Capparis masaikai Lévl

Mabinlin II is one of the major sweet proteins stored in the seeds of Capparis masaikai Lévl. Its promoter region (779 bp) located 5′ upstream of the mabinlin II gene has been isolated and named as MBL-779 (GenBank accession number, EU014073). This promoter contains two typical TATA box regions and a series of motifs related to seed-specific promoters, such as ACGT motifs, RY motif, napin motif, and G box. The MBL-779 promoter drove GUS gene to transiently express in the embryos of bean, maize, and rice seeds or to constantly express in the embryos and anthers of the transgenic Arabidopsis. The MBL-779 promoter regulated gene expression from approximately the 12th day and peaked on approximately the 16th day after flowering in Arabidopsis. The −300-bp promoter region is a minimal sequence required to functionally regulate gene expression. The CAATs at −325 to −322 bp and −419 to −416 bp and the region at −485 to −770 bp play a role in the quantitative regulation of gene expression. The RY motif, CATGAC, at −117 to −112 bp and the ACGT within the G box (CACGTG) at −126 to −123 bp positively regulate gene expression. X.-W. Hu and S.-X. Liu have the same contribution as first author.     

无核荔枝胚胎发育时期蛋白质图谱分析

通过二维聚丙烯酰胺凝胶电泳(2DE)以及计算机辅助的图像分析技术,对荔枝开花后20d的正常与败育胚蛋白质图谱进行了初步分析。结果表明,正常胚总蛋白质斑点数为129,败育胚总蛋白质斑点数为130,其中24个蛋白质点在两种胚中的表达丰度没有明显变化,35个蛋白质点在表达丰度上有明显差异,55%的蛋白则发生了蛋白质缺失、增加以及位置改变等变化。这两种蛋白质组的表达差异说明了胚内蛋白质成分在其败育过程中发生了变化,这些蛋白可能参与了胚败育的调节和控制。     

The cellular redox state in plant stress biology – A charging concept

Different redox-active compounds, such as ascorbate, glutathione, NAD(P)H and proteins from the thioredoxin superfamily, contribute to the general redox homeostasis in the plant cell. The myriad of interactions between redox-active compounds, and the effect of environmental parameters on them, has been encapsulated in the concept of a cellular redox state. This concept has facilitated progress in understanding stress signalling and defence in plants. However, despite the proven usefulness of the concept of a redox state, there is no single, operational definition that allows for quantitative analysis and hypothesis testing.     

玉米Rab1B基因功能的初步研究

在酿酒酵母中,GTP结合蛋白YPTl调节蛋白质从内质网到高尔基体的运输.YPT1温敏突变株ASY01等在26℃能正常生长,但在高温(37℃)条件下,细胞死亡.经鉴定,YPT1温敏突变是由于第136位的丙氨酸突变为天冬氨酸.克隆一个玉米Rab基因,分子进化研究表明它是一个Rab1基因,命名为ZmRab1B.与酵母YPT1温敏突变体的功能互补实验结果表明,ZmRab1B基因能恢复酵母YPT1温敏突变株的正常生长,说明ZmRab1B基因的功能是调节蛋白质从内质网到高尔基体的运输.