Expression of the <Emphasis Type="Italic">zga</Emphasis> agglutinin gene in tobacco can enhance its anti-pest ability for peach-potato aphid (<Emphasis Type="Italic">Myzus persica</Emphasis>)

The effect of introduction of the Zephyranthes grandiflora agglutinin gene (zga) to tobacco on its anti-pest ability for peach-potato aphids was investigated. PCR analysis confirmed that the zga gene was integrated into the plant genome. The results from semi-quantitative RT-PCR and real-time PCR assays revealed that the zga gene was expressed at various levels in the transgenic plants. A bioassay with aphids indicated that transgenic plants conferred enhanced resistance to aphids. Compared with the controls, the average number of aphids fed with transgenic plants during a 20-day assay evidently decreased by 70.4% in leaf disc bioassay and 77.9% in whole plant bioassay. The average number of nymph was significantly reduced by 36.4% on zga-expressing plants in leaf disc bioassay and 35.6% in whole plant bioassay. The report indicated that the introduction of zga gene to tobacco plants is a useful method to improve its anti-pest ability for aphids.     

正交设计优化微波辅助测定延胡索叶总生物碱含量

通过微波辅助提取的方式,以延胡索叶总生物碱含量为考察指标,通过单因素试验和正交试验对总生物碱提取方法进行优化。重点考察了微波提取温度、时间、料液比、提取缓冲液pH值等因素对延胡索叶总生物碱得率的影响。各因素对延胡索叶总生物碱提取量的影响大小依次为:提取缓冲液pH值料液比提取温度。其最佳的提取方法为:提取缓冲液pH值为1. 0,料液比1∶100,提取温度60℃,提取时间20 min。在此条件下,叶总生物碱含量为25. 910 mg/g。利用微波辅助提取延胡索叶中总生物碱,不仅耗时短,效率高,而且操作简单、稳定,为延胡索叶总生物碱含量测定提供一定的技术支持。     

Proteome alteration of U251 human astrocytoma cell after inhibiting retinoic acid synthesis

Retinoic acid (Ra) is crucial for the patterning and neuronal differentiation in the central nervous system (CNS). Ra deficiency in animals disrupts the motor activities and memory abilities. The molecular mechanisms underlying these behavior abnormalities remain largely unknown. In the current study, we treated the astrocytoma cells with citral, an inhibitor of Ra synthesis. We analyzed the differences in the protein concentrations between the treated and untreated astrocytoma cells by two-dimensional gel electrophoresis (2-DE), Imagemaster software, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In total, 39 of 46 altered protein spots with significant mascot scores were identified representing 36 proteins, that were involved in significantly altered glutamate metabolism, lipid metabolism, mitochrondrial function, and oxidative stress response by Ingenuity Pathway Analysis (IPA). Altered 3-phosphoglycerate dehydrogenase (PHGDH) was also observed in western blot. These data provide some clues for explaining the behavioral changes caused by Ra deficiency, and support the hypothesis that Ra signaling is associated with some symptoms of neurodegenerative disorders and schizophrenia.     

Molecular characterization and expression analysis of a gene encoding mannose-binding lectin from bulb of Zephyranthes grandiflora

In this paper we report on the molecular cloning, sequencing and partially characterisation of a lectin from bulb of the Chinese medicinal plant Zephyranthes grandiflora. The full-length cDNA of Z. grandiflora bulb lectin (ZGBL) consisted of 986 bp and contained a 576 bp ORF encoding a 191 amino acid protein. Bioinformatics analysis results clearly indicate that ZGBL belongs to the monocot mannose-binding lectin family, which contains 3 putative mannose-binding sites per subunit. RT-PCR analysis results indicate that ZGBL is constitutively expressed in all the tested tissue types including root, bulb, leaf and flower. Interestingly, ZGBL is more closely related to the Orchidaceae rather than the Amaryllidaceae family on molecular evolution.     

Functional identification of hyoscyamine 6β-hydroxylase from <Emphasis Type="Italic">Anisodus acutangulus</Emphasis> and overproduction of scopolamine in genetically-engineered <Emphasis Type="Italic">Escherichia coli</Emphasis>

Hyoscyamine 6β-hydroxylase (H6H; EC 1.14.11.11) converts hyoscyamine to scopolamine in the last step of scopolamine biosynthetic pathway. The gene encoding H6H in Anisodus acutangulus was cloned and expressed in Escherichia coli and the recombinant proteins fused with His-tag or GST-tag at its N-terminal were purified and then confirmed by Western bolt analysis. The biofunctional assay revealed that the His-AaH6H and GST-AaH6H converted hyoscyamine (40 mg/l) to scopolamine at 32 and 31 mg/l, respectively. This is the first report on AaH6H expression, purification and functional characterization facilitates further genetic improvement of scopolamine yield in A. acutangulus.     

Metabolomic profiling to identify potential serum biomarkers for schizophrenia and risperidone action

Despite recent advances in understanding the pathophysiology of schizophrenia and the mechanisms of antipsychotic drug action, the development of biomarkers for diagnosis and therapeutic monitoring in schizophrenia remains challenging. Metabolomics provides a powerful approach to discover diagnostic and therapeutic biomarkers by analyzing global changes in an individual's metabolic profile in response to pathophysiological stimuli or drug intervention. In this study, we performed gas chromatography-mass spectrometry based metabolomic profiling in serum of unmedicated schizophrenic patients before and after an 8-week risperidone monotherapy, to detect potential biomarkers associated with schizophrenia and risperidone treatment. Twenty-two marker metabolites contributing to the complete separation of schizophrenic patients from matched healthy controls were identified, with citrate, palmitic acid, myo-inositol, and allantoin exhibiting the best combined classification performance. Twenty marker metabolites contributing to the complete separation between posttreatment and pretreatment patients were identified, with myo-inositol, uric acid, and tryptophan showing the maximum combined classification performance. Metabolic pathways including energy metabolism, antioxidant defense systems, neurotransmitter metabolism, fatty acid biosynthesis, and phospholipid metabolism were found to be disturbed in schizophrenic patients and partially normalized following risperidone therapy. Further study of these metabolites may facilitate the development of noninvasive biomarkers and more efficient therapeutic strategies for schizophrenia.     

Characterization and expression profile analysis of a new cDNA encoding taxadiene synthase from Taxus media

A full-length cDNA encoding taxadiene synthase (designated as TmTXS), which catalyzes the first committed step in the Taxol biosynthetic pathway, was isolated from young leaves of Taxus media by rapid amplification of cDNA ends (RACE). The full-length cDNA of TmTXS had a 2586 bp open reading frame (ORF) encoding a protein of 862 amino acid residues. The deduced protein had isoelectric point (pI) of 5.32 and a calculated molecular weight of about 98 kDa, similar to previously cloned diterpene cyclases from other Taxus species such as T. brevifolia and T. chinenisis. Sequence comparison analysis showed that TmTXS had high similarity with other members of terpene synthase family of plant origin. Tissue expression pattern analysis revealed that TmTXS expressed strongly in leaves, weak in stems and no expression could be detected in fruits. This is the first report on the mRNA expression profile of genes encoding key enzymes involved in Taxol biosynthetic pathway in different tissues of Taxus plants. Phylogenetic tree analysis showed that TmTXS had closest relationship with taxadiene synthase from T. baccata followed by those from T. chinenisis and T. brevifolia. Expression profiles revealed by RT-PCR under different chemical elicitor treatments such as methyl jasmonate (MJ), silver nitrate (SN) and ammonium ceric sulphate (ACS) were also compared for the first time, and the results revealed that expression of TmTXS was all induced by the tested three treatments and the induction effect by MJ was the strongest, implying that TmTXS was high elicitor responsive.