3-34 Gene Mining: Association Analysis of the Whole Genome Re-sequencing and the Map-based Cloning

Since the whole genome sequence of Arabidopsis thaliana ecotype Columbia (Col-0) was published in 2 000, the focus of genomics study had turned from structural genomics to functional genomics era[1]. In the post genomics era, mutants play an important role for gene function exploring. Therefore, acquiring various variants and studying on them are useful for understanding the mechanism of plant development and molecular design for plant breeding.

Cloning and Functional Validation of Mung Bean VrPR Gene

For the purpose of functional validation,the mung bean(Vigna radiata)VrPR gene was cloned and overexpressed in Arabidopsis thaliana.Thefindings revealed that the ORF of VrPR contained 1200 bp,in which 399 amino acids were encoded.Bioinformatics analysis showed that the VrPR protein belonged to the NADB Rossmann superfamily,which was one of the non-transmembrane hydrophilic proteins.VrPR was assumed to have 44 amino acid phosphorylation sites and be contained in chloroplasts.The VrPR secondary structure comprised of random coil,αhelix,βangle,and extended chain,all of which were quite compatible with the anticipated tertiary structure.Moreover,analysis of the phylogenetic tree indicated that the soybean PR(Glyma.12G222200)and VrPR were closely related.Furthermore,chlorophyll content in leaves is markedly increased in Arabidopsis when VrPR is overexpressed.Ourfindings will serve as a reference for more functional studies on the PR genes in mung bean.

Cloning and Bioinformatics Analysis of vscB Gene of T3SS Chaperone of Vibrio alginolyticus

[Objectives]To clone and analyze the vscB gene of Vibrio alginolyticus HY9901 by bioinformatics.[Methods]A pair of specific primers were designed according to the vscB gene sequence of Vibrio alginolyticus HY9901.The full length of the primers was cloned by PCR and analyzed by bioinformatics.[Results]The vscB gene was 429 bp long,encoding 142 amino acids,with a theoretical molecular weight of 16.4 kDa and a pI value of 5.48.Amino acid sequence analysis of VscB showed that VscB was not a secretory protein,without signal peptide and transmembrane region,and there were protein kinase C phosphorylation site and casein kinase II phosphorylation site in the sequence.Homologous comparison of amino acid sequences showed that VscB of V.alginolyticus had the highest protein similarity with Vibrio Parahaemolyticus,reaching 91%.Phylogenetic tree analysis showed that the corresponding proteins of V.alginolyticus VscB,Vibrio Parahaemolyticus and Vibrio diabolicus were clustered in the same subfamily.Functional domain analysis showed that it had CesT family domain.Tertiary structure prediction showed that there were 3α-helices and 5β-turns in VscB protein.[Conclusions]This study provided a theoretical basis for further study on the function of chaperone of V.alginolyticus.

Cloning of differentially expressed genes in human hepatocellular carcinoma and nontumor liver

INTRODUCTIONThe mechanism of hepatocellular carcinoma(HCC)is still unclear,although some genes have been found to play a role in the transformation of liver cells,and a variety of studies have described differences in gene expression which distinguished tumor from nontumor[1-6].The new genes,especially the functional genes directly related with tumor are still worth being found.The purpose of our study is to find the different genes between human liver tumor and normal tissues using suppression subtractive hybridization.

Molecular Cloning and Functional Characterization of a Salt Tolerance-Associated Gene IbNFU1 from Sweetpotato

Iron-sulfur cluster biosynthesis involving the nitrogen fixation（Nif） proteins has been proposed as a general mechanism acting in various organisms.NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses.Based on the EST sequence selected from salt-stressed suppression subtractive hybridization（SSH） cDNA library constructed with a salt-tolerant mutant LM79,a NFU gene,termed IbNFU1,was cloned from sweetpotato（Ipomoea batatas（L.） Lam.） via rapid amplification of cDNA ends（RACE）.The cDNA sequence of 1 117 bp contained an 846 bp open reading frame encoding a 281 amino acids polypeptide with a molecular weight of 30.5 kDa and an isoelectric point（pI） of 5.12.IbNFU1 gene contained a conserved Cys-X-X-Cys motif in C-terminal of the iron-sulfur cluster domain.The deduced amino acid sequence had 66.08 to 71.99% sequence identity to NFU genes reported in Arabidopsis thaliana,Eucalyptus grandis and Vitis vinifera.Real-time quantitative PCR analysis revealed that the expression level of IbNFU1 gene was significantly higher in the roots of the mutant LM79 compared to the wild-type Lizixiang.Transgenic tobacco（cv.Wisconsin 38） plants expressing IbNFU1 gene exhibited significantly higher salt tolerance compared to the untransformed control plants.It is proposed that IbNFU1 gene has an important function for salt tolerance of plants.

Cloning and Characterization of a Pathogenesis-Related Protein Gene TaPR10 from Wheat Induced by Stripe Rust Pathogen

Pathogenesis-related proteins （PRs） play many important roles in plant defense response against pathogen attack. To better understand the molecular mechanism of PR genes involved in wheat adult plant resistance （APR） to stripe rust, based on a differentially expressed transcribed derived fragment （TDF）, a novel PR gene from wheat cv. Xingzi 9104 infected by the Puccinia striiformis Westend f. sp. tritici Erikss. pathotype CY32, which was highly similar to the maize ZmPRIO gene and designated as TaPRIO, was identified using in silico cloning and RT-PCR method. This novel TaPRIO gene was predicted to encode a 160-amino acid protein with a deduced molecular weight of 17.06 kDa and an isoelectronic point （pI） of 5.19. An amino acid sequence analysis of TaPR10 demonstrated the presence of a typical conserved domain of pathogenesis related protein Bet v I family. Multiple alignment analysis based on the amino acids encoded by 10 different PRIO genes from maize （Zea mays）, rice （Oryza sativa）, broomcorn （Sorghum bicolor）, and wheat （Triticum aestivum） indicated that PR proteins of class 10 was conserved among the 4 plant species with about 80% similarity. DNA sequence of TaPRIO suggested the presence of one 84-bp intron with the splicing sites of GT-AT bi-nucleotide sequence between 188 and 271 bp. Using a real-time quantitative RT-PCR （qRT-PCR）, expression profiles of TaPRIO revealed that at the adult-plant stage, TaPRIO transcript was up-regulated as early as 12 h post-inoculation （hpi）, with the occurrence of maximum induction at 24 hpi. At the seedling stage, TaPRIO was also slightly induced 18 hpi. However, the transcript amount was relatively lower than that of the adult-plant stage. Taken together, these results suggest that TaPRIO may participate in wheat defense response of APR to stripe rust.

Cloning and Functional Analysis of Lycopene ε-Cyclase (IbLCYe) Gene from Sweetpotato, Ipomoea batatas (L.) Lam.

This paper reported firstly successful cloning of lycopene ε-cyclase （lbLCYe） gene from sweetpotato, lpomoea batatas （L.） Lam. Using rapid amplification of cDNA ends （RACE）, lbLCYe gene was cloned from sweetpotato cv. Nongdafu 14 with high carotenoid content. The 1 805 bp cDNA sequence oflbLCYe gene contained a 1236 bp open reading frame （ORF） encoding a 411 amino acids polypeptide with a molecular weight of 47 kDa and an isoelectric point （pI） of 6.95. IbLCYe protein contained one potential lycopene ε-cyclase domain and one potential FAD （flavinadenine dinucleotide）/NAD（P） （nicotinamide adenine dinucleotide phosphate）-binding domain, indicating that this protein shares the typical characteristics of LCYe proteins. The gDNA oflbLCYe gene was 4 029 bp and deduced to contain 5 introns and 6 exons. Real-time quantitative PCR analysis revealed that the expression level of IbLCYe gene was significantly higher in the storage roots of Nongdafu 14 than those in the leaves and stems. Transgenic tobacco （cv. Wisconsin 38） expressing [bLCYe gene accumulated significantly more ^-carotene compared to the untransformed control plants. These results showed that lbLCYe gene has an important function for the accumulation of carotenoids of sweetpotato.

Identification of a marine agarolytic bacterium Agarivorans albus QM38 and cloning and sequencing its beta-agarase genes

A total of 117 agar-decomposing cultures were isolated from coastal seawater around Qingdao, China. The phenotypic and agarolytic features of an agarolytic isolate, QM38, were investigated. The strain was gram negative, strictly aerobic, curved rod and polar flagellum. On the basis of several phenotypic characters, biochemical and morphological characters and phylogenetic analysis of the gene coding for the 16S rRNA, the strain was identified as Agarivorans albus strain QM38. This strain can liquefy the agar on the solid agar plate. An excellular agarase activity was determined in liquid culture. The enzyme exhibited maximal activity at 40 ℃, pH 7.6. Its activity was greatly affected by different concentrations of agarose. The highest activity 32 U/ml was achieved in the culture supernatant. The hydrolytic product was analyzed by fluorophore-assisted carbohydrate electrophoresis （FACE）. After complete hydrolysis of agarose, a series of agaro-oligosaccharides were produced. The main products of the enzymes were oligosaccharides in the degree of polymerization （DP） of 2, 4, 6 and 8. Three genes agaD01, agaD02 and agaD03, encodingβ-agarases, had been cloned from genomic DNA of Agarivorans albus strain QM38. The open reading frame of agaDOl, consisted of 2 988 bp, and shared 95.5%-98.9% identity to the β-agarase genes of some strains of Vibrio and Agarivorans. Gene agaD02 comprised 2 868 bp and encoded a 955- amino-acid protein. It showed 97.4% and 98.7~0 identity to the β-agarase genes of strain Vibrio sp. PO-303 and strain Vibrio sp. JT0107, respectively. Only partial sequence of agaD03 gene has been cloned. It showed 96.5% identity to β-agarase gene （agaB） of Pseudoalteromonas sp. CY24, and shared 96.8% identity to β-agarase-c gene of Vibrio sp. PO-303.

Cloning and expression analysis of the chloroplast fructose-1,6-bisphosphatase gene from Pyropia haitanensis

Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplification of cDNA ends（RACE） technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, including a 5′ untranslated region（UTR） of 92 bp, a 3′？UTR of 69 bp, and an open reading frame（ORF） of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR revealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.

Research Progress of Medicinal Secondary Metabolites and Gene Cloning of Dendrobium officinale

Dendrobium officinale is one of the most precious medicinal plants in China. Its main medicinal ingredients are its secondary metabolites. However,it has the characteristics of limited sources,low active ingredient content and high cost,limiting the use of D. officinale.Studying the network structure and rate-limiting steps of secondary metabolites of medicinal components of D. officinale,analyzing the secondary metabolic synthesis process,mastering the production rules of its medicinal components and carrying out gene cloning or biosynthesis,etc.are of great significance for the rational development and utilization of D. officinale resources. This paper briefly reviews the progress of the research on the secondary metabolites of D. officinale,including the detection and identification of metabolites and the identification and cloning of key metabolic enzymes.

Molecular cloning and expression under abiotic stresses and hormones of the ethylene response factor Ⅶ gene FmRAP2.12 from Fraxinus mandshurica

RELATED TO AP2.12(RAP2.12)is one of the Ethylene Response Factors(ERF)transcription factor and plays a key role in controlling plant root bending and responding to multiple abiotic stresses including hypoxia stress.In this study,FmRAP2.12 gene was isolated and characterized from Fraxinus mandshurica Rupr.The open reading frame(ORF)of FmRAP2.12 was 1170 bp and encoded a protein of 389 amino acids.The conserved domains,three-dimensional phylogenetic relationship of FmRAP2.12 was also investigated.Quantitative real-time(qRT-PCR)analyzed the expression of FmRAP2.12 in different tissues.The expression level of FmRAP2.12 was highest in roots followed by leaves,and lowest in male flowers.Abiotic stress and hormone signal-induced expression was established using qRT-PCR.Salt stress induced FmRAP2.12 to a double peak pattern:the first peak value was at 6 h and the second at 72 h.Drought stress also induced FmRAP2.12 to a double peak pattern:the first at6 h and the second at 48 h.FmRAP2.12 was up-regulated after initiation of gibberellic acid(GA3)treatment,with a one peak pattern at 24 h.FmRAP2.12 may not respond to cold stress and Abscisic acid(ABA)treatment.The transient overexpression of FmRAP2.12 caused the up-expression of downstream key genes of abiotic stress response and gibberellin pathway.Our research reveals the molecular characteristic and expression patterns under abiotic stress and hormone condition of FmRAP2.12,providing support for the genetic improvement of F.mandshurica at a molecular level.

Cloning and Expression Analysis of an AP2/ERF Gene and Its Responses to Phytohormones and Abiotic Stresses in Rice

Ethylene response factors （ERFs） play important roles in response to plant biotic and abiotic stresses. In this study, a gene encoding a putative AP2/ERF domain-containing protein was isolated by screening a SSH cDNA library from rice and designated as Oryza sativa AP2/ERF-like protein （OsAP2LP） gene. OsAP2LP is 1491 bp in length, interrupted by seven introns, and encodes a putative protein of 348 amino acids. Temporal and spatial expression analysis showed that the OsAP2LP gene was preferentially expressed in roots, panicles, mature embryos and seeds in rice. Real-time quantitative PCR analysis indicated that the expression levels of the OsAP2LP gene were increased under the treatments of drought and gibberellin but decreased under the treatments of low temperature, salt, abscisic acid （ABA） and zeatin. Taken together, these results suggest that OsAP2LP might be involved in stress responses, and probably plays roles as a transcription regulator when plants response to cold, salt and drought stresses through ABA and gibberellin pathways.

Cloning and Expression Analysis of OsNADPH1 Gene from Rice in Drought Stress Response

An experiment was conducted to compare the mRNA expression difference in rice leaves and roots under drought stress and normal conditions us, ng Fluorescent Differential Display （FDD） method. One positive fragment was isolated by combination of the H. A. Yellow-PAGE （cont,~ined 0.1% H. A. Yellow） separation and macroarray screening methods. Compared to Arabidopsis thaliana NADPH oxidoreductase gene, it has 96% identity. The cDNA was 1423 bp, and contained a complete open reading frame of 1048 bp encoding a protein with 345 amino acid residues. Moreover, the gene expression level was higher under drought stress than that under normal conditions. The possible role of NADPH oxidoreductase gene under drought response was also discussed.

Cloning and Sequence Analysis of a Novel Cold-Adapted Lipase Gene from Strain lip35 (Pseudomonas sp.)

A combination method of the usual-PCR and reverse-PCR for the cloning of a novel lipase gene directly from the total genomic DNA of strain lip35 （Pseudomonas sp.） is described, whereby a lipase gene （lip） was cloned directly from genomic DNA. The sequence data have been deposited in the GenBank and EMBL data bank with the accession number EU414288. The nucleotide sequence showed a major open reading frame encoding a 59-kDa protein of 566 amino acid residues, which contained a lipase consensus sequence GXSXG. The lipase lip had 74 and 70% homologies with the lipases of an uncultured bacterium and P. fluorescens PfO-1, respectively, but it did not show any overall homology with lipases from other origins. The functional lipase was obtained when the lip gene was expressed in Pichia pastoris GS115.

Cloning and characterization of a stearoyl-ACP desaturase gene from Jatropha curcas

Using degenerate primers and RT-PCR, RACE techniques, a 1491 bp cDNA segment of stearoyl-acyl carrier protein desaturase （SAD） is cloned from developing seeds of Jatropha curcas L. The segment contains a 1191 bp of complete open reading frame （ORF）. Analysis in the BLAST on NCBI shows that Jatropha curcas SAD （JSAD） gene encodes a protein precursor composed of a signal peptide of 33 amino acids and a mature peptide of 363 amino acids. The homological analysis shows that JSAD has high level of homology both in nucleotide sequence and in amino acid sequence to other plants SADs. The nucleotide and peptide identity of JSAD to Ricinus communis SAD （RSAD） is up to 89% and 96.2% respectively. Molecular modeling of JSAD indicates that its three-dimensional structure strongly resembled the crystal structure of RSAD.

CLONING AND ANALYSIS OF PHYCOERYTHRIN GENES IN GRACILARIA LEMANEIFORMIS (RHODOPHYCEAE)

Cloning and sequencing of the genes coding for the α and β subunit of phycoerythrin (PE) of a red alga- Gracilaria lemaneiformis (GL) are reported. Alignment of 1084 nucleotides sequenced with three known red algal PE genes, Rhodella violacea (RV), Polysiphonia boldii (PB) and Aglaothamnion neglectum (AN), showed high level of conservation, and similarities of 77.6% (between GL and RV), 77.9% (GL and AN) and 79.0% (GL and PB). The similarities of amino acids were 84.8% (between GL and RV), 85.7% (GL and PB), and 80.6% (AN and GL), higher than those among nucleotides.

CLONING AND SEQUENCING OF THE ALLOPHYCOCYANIN GENES FROM SPIRULINA MAXIMA (CYANOPHYTA)

The genes coding for the α-and β-subunit of allophycocyanin (apcA and apcB) fromthe cyanophyte Spirulina maxima were cloned and sequenced. The results revealed 44.4% of nucleotidesequence similarity and 30.4% of similarity of deduced amino acid sequence between them. The aminoacid sequence identities between S. maxima and S. platensis are 99 .4% for α subunit and 100% for βsubunit.

Positional cloning of PmCH1357 reveals the origin and allelic variation of the Pm2 gene for powdery mildew resistance in wheat

Powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici(Bgt), is a prevalent disease in common wheat(Triticum aestivum L.) and causes serious yield losses worldwide. We used a map-based approach to clone the major broad-spectrum powdery mildew resistance gene Pm CH1357 from wheat breeding line CH1357. Pm CH1357 was mapped to a 526 kb region containing only Traes CS5 D01 G044600. The Traes CS5 D01 G044600 sequence of the susceptibility allele in Taichung 29(TC29) was identical to that in Chinese Spring, whereas the sequence of the resistance allele in CH1357 was identical to Pm2a previously cloned from the germplasm Ulka/*8Cc. The susceptibility allele in TC29 contained a 7 bp deletion in exon 1, resulting in loss of 856 of the 1277 amino acids in the predicted nucleotide-binding domain leucine-rich repeat containing Pm2a protein.Pm CH1357/Pm2a sequence was also isolated from the Chinese wheat landraces and cultivars that were previously reported to possess the resistance gene Pm2b, Pm2c,PmLX66, or PmND399. The Pm CH1357/Pm2a resistance allele was present in 10 of 495 accessions in core germplasm and contemporary cultivars from China and the USA. A newly developed diagnostic marker for the 7 bp In Del in the resistance gene can be used to eliminate the susceptibility allele in wheat breeding programs.

Cloning One CIPK Gene from a Thermo-Sensitive Genic Self-Incompatible Line in Maize Expressing Under Different Temperatures

A calcineurin B-like protein-interacting protein kinases （CIPK） gene was cloned （EU 424058） from a thermo-sensitive genic self-incompatibility （TSGI） line, HE97, in maize, which was selected for suppression subtractive hybridization （SSH） library of the self-incompatible and self-compatible silks of the TSGI line under different temperatures. The full-length cDNA of the candidate CIPK-like gene consisted of 1 918 nucleotides and contained a 1 332-bp open reading frame in maize. Real-time PCR indicated that the candidate CIPK-like gene was highly expressed in the self-incompatible pollen of the TGSI line, and promoted elevated levels of calcium （Ca2＋）. High Ca2＋ concentrations in the pollen strongly inhibit pollen tube formation in silk of the same plant, thus inducing self-incompatibility （SI） under high temperature. These results implied that the CIPKs-like gene would play an important role in the regulation of HE97 characteristics under different temperatures, perhaps acting as a secondary messenger in the expression of SI in the TGSI line in maize.

Gene Cloning and Expression Analysis of G Protein αq Subunit from Helicoverpa assulta (Guenée)

The cDNA encoding the G protein αq subunit was isolated from the antennae of Helicoverpa assulta （Guen6e） by reverse transcription polymerase chain reaction （RT-PCR） and named as HassGαq. Sequencing analysis showed that the fulllength of HassGαq open reading frame （ORF） is 1 062 bp, 353 amino acid residues are encoded. The predicted molecular weights （MW） and isoelectric point （PI） are 41.5 kD and 5.15, respectively. HassGαq gene was then constructed into expression vector pGEX-4T-2 for over expression in prokaryotic cells. The SDS-PAGE and Western blot analysis showed that induced by Isopropyl-β-D-Thiogalactoside （IPTG）, the GST-HassGαq fusion protein is expressed in Escherichia coil BL21, and its MW was found to be about 66 kD nearly equal to the predicted. In addition, RT-PCR analysis showed that the expressions of HassGαq are not tissue specific.