摘要：[Objective] This study aimed to explore the molecular mechanism of senescence in ethylene-insensitive flowers. [Method] The dahlia petals were used as matedal, and the senescence-associated proteins were isolated and identified using two-dimensional electrophoresis, mass spectrometry and an encoding gene was cloned using molecular biology techniques. [Result] In the two-dimensional elec- trophorogram of proteins from dahlia petals at building color, full flowering and flow- er senescence pedods, a total of 44 protein spots with differences in expression level more than two times were detected. From the 44 protein spots, xyloglucan （XTHs）, a senescence-associated protein, was iso- lated and identified and its expression level was increased continuously with the senescence process of dahlia petals. By using the total RNA of dahlia petals as matedal and a pair of degenerate pdmers, the cDNA sequence of XTH gene was cloned by RT-PCR. The encoding region of XTH gene has a full length of 882 bp, encoding 293 amino acid residues, and is named as DpXTH1 （Accession number： HM053613.1）. The cluster analysis showed that the amino acid sequence of DpXTH1 has high homology with those of XTHs in other plants. [Conclusion] The isolated and identified DpXTH1 from dahlia petals belonged to the XTH family in plants, and its biological function was associated with the senescence process and regulation of dahlia petals.

摘要：Ubiquitin (UBI) plays a very important role in regulated non-lysosoma l ATP dependent protein degradation. In the present work, the coding sequence of Spodoptera litura UBI gene was isolated (GenBank Accession No. AF436066). Th e le ngth of this ORF is 228bp, encoding a protein with Mr of 8.56 kD and isoelectri c point of 6.56. Multiple sequence alignment indicated that *** UBI is very similar to the homologous proteins of other eukaryotic species and it has 84% id entity with *** nucleopolyhedrovirus (SpltMNPV) UBI at amino acid level . RT -PCR analysis showed that *** UBI gene is ubiquitously expressed in la rva t issues which are susceptible to SpltMNPV infection. By constructing *** e xpre ssion vector, *** UBI was highly expressed and the recombinant protein was purified using Ni-NTA resin column, and currently further study on the function of *** UBI in SpltMNPV infection is underway.

摘要：[Objective] The aim was to clone the CmNAC gene from Cucurbita moschata and analyze the sequence characteristics. [Method] A pair of degenerate primers was designed based on the conserved sequences of NAC gene from Brassica napus, Lycopersicon esculentum and Capsicum annuum. NAC transcription factor gene was amplified by RT-PCR from Cucurbita moschata leaves and cloned into pMD-19T vector; then the recombinant clones were sequenced. Finally, the sequences of nucleic acid and amino acid were analyzed using BLAST and DNAMAN software. [Result] The NAC transcription factor gene cloned from C. moschata included 442 bp encoding 147 amino acids, named CmNAC. The NAC gene fragment contained a conserved region like other plant NAC genes and belonged to the NAC family ATAF1/2 subfamily. [Conclusion] The stress resistance related gene NAC cloned from C. moschata is a foundation for further study on the biological function of the gene and plant genetic engineering.

摘要：[Objective]The aim was to construct the wheat heat-shock protein 60 （HSP60） gene in prokaryotic expression vector and express HSP60 efficiently in ***. [Method]According to the wheat HSP60 gene sequence in GenBank,a pair of primers P1/P2 were designed and synthesized. The wheat HSP60 gene fragment was amplified from the wheat RNA by RT-PCR and inserted into bacterial expression vector of pGEX-4T-1. The construct of pGEX-4T-1-HSP60 was subsequently transformed into *** BL21. [Result]The construct of pGEX-4T-1-HSP60 was verified by restriction endonuclease digestion and sequenced. Compared with the sequences of wheat HSP60 genes in GenBank,homology accounted to 100%. Expression of the GST-HSP60 fusion protein was induced with IPTG. Its molecular weight was about 90 kD. The result was identified by electrophoresis of SDS-PAGE. Expression of the protein bands was consistent with the expected size. [Conclusion]The recombinant prokaryotic expression vector in pGEX-4T-1-HSP60 was constructed successfully and expressed stably in *** BL21. This will lay the foundation for further study on the functions of the protein and its mechanism.

摘要：Contamination of soil and water by arsenic is a global problem. In Australia, the dipping of cattle in arsenic-containing solution to control cattle ticks in last centenary has left many sites heavily contaminated with arsenic and other toxicants. We had previously isolated five soil bacterial strains （CDB 1-5） highly resistant to arsenic. To understand the resistance mechanism, molecular studies have been carried out. Two chromosome-encoded arsenic resistance （ars） gene clusters have been cloned from CDB3 （Bacillus sp.）. They both function in Escherichia coli and cluster i exerts a much higher resistance to the toxic metalloid. Cluster 2 is smaller possessing four open reading frames （ORFs） arsRorf2BC, similar to that identified in Bacillus subtilis Skin element. Among the eight ORFs in cluster 1 five are analogs of common ars genes found in other bacteria, however, organized in a unique order arsRBCDA instead of arsRDABC. Three other putative genes are located directly downstream and designated as arsTIP based on the homologies of their theoretical translation sequences respectively to thioredoxin reductases, iron-sulphur cluster proteins and protein phosphatases. The latter two are novel of any known ars operons. The arsD gene from Bacillus species was cloned for the first time and the predict protein differs from the well studied E. coli ArsD by lacking two pairs of C-terminal cysteine residues. Its functional involvement in arsenic resistance has been confirmed by a deletion experiment. There exists also an inverted repeat in the intergenic region between arsC and arsD implying some unknown transcription regulation.

摘要：Diapause hormone (DH) is a neurohormone which is secreted from suboesophageal ganglion and responsible for induction of embryonic diapause in Bombyx ***,using bioassay,we present evidence that Has-SGNPⅠ,which clearly exhibited diapause egg inducing activity as does Bom-DH,is likely to be *** reported the molecular characterization of the Helicoverpa assulta diapause hormone analog by polymerase chain reaction.A 665?bp fragment containing the entire DH-like gene was isolated and ***-like gene comprised two exons interspersed by a single intron,and the consensus sequence for splicing junction is identified at the exon/intron *** result shows that DH-like gene is localized in the genome of Helicoverpa assulta.

摘要：[Objective] The aim was to clone ISA1 from Oryza sativa and analyze its expression situation in different tissues and different endosperm filling stage.[Method] With japonica rice cultivar nipponbare as test material,the expression patterns of ISA1 in different tissues and different endosperm filling stage was analyzed by using semi-quantitative RT-PCR technique.[Result]The full length open reading fragments of ISA1 encoded 811 amino acid *** homologous alignment and phylogenetic analysis showed th...