Defect in an immune regulator gene BrSRFR1 leads to premature leaf senescence in Chinese cabbage

Leaf senescence is the final stage of leaf development, where the nutrients and energy of senescent leaves are redistributed to developing tissues or organs for plant growth, reproduction, and defense. Outer leaves are photosynthetic organs that usually senesce at the late heading stage in Chinese cabbage, and premature leaf senescence often reduces leafy head yield and quality. In this study, 11 premature leaf senescence mutants were screened from an ethyl methanesulfonate-mutagenized population of the double haploid line ‘FT' in Chinese cabbage. At the early heading stage, the mutants exhibited edge yellowing within its outer leaves, and at the mature stage, its leafy head weight decreased significantly. Genetic analysis revealed that the mutated trait of all 11 mutants corresponds to single gene recessive inheritance. Semi-diallel cross tests showed that 5 of the 11 were allelic mutants. MutMap and Kompetitive Allele Specific PCR genotyping revealed that BraA01g001400.3C was the candidate gene, which is orthologous of Arabidopsis SUPPRESSOR OF rps4-RLD 1, encoding an immune regulator, so we named it as BrSRFR1. All the BrSRFR1 in the five allelic mutants exhibited single nucleotide polymorphisms at different positions on their exons and led to premature translation termination, which confirmed that defect in BrSRFR1 led to premature leaf senescence. These results verify the role of Br SRFR1 on leaf senescence and provide a new insight into the mechanisms of leaf senescence in Chinese cabbage, which reveals a novel function of SRFR1 in plant development.

Molecular Cloning and Bioinformatics Analysis of msrA Gene from Vibrio alginolyticus Strain HY9901

[Objectives]This study was conducted to understand the structure and function of MsrA protein.[Methods]With Vibrio alginolyticus HY9901 as the object of study,primers were designed to amplify the full-length gene of msrA,and its bioinformatics analysis was carried out.[Results]The full length of msrA gene was 639 bp,encoding 212 amino acids,and its theoretical molecular weight was about 23729.60 Da.The protein had a stable structure,and it was hydrophobic overall.The structure of signal peptides at the N terminal of the amino acid sequence was predicted,and it was found that there was no signal peptide cleavage site and no transmembrane region.The amino acid sequence of MsrA contained multiple signal binding sites.Protein subcellular localization showed that MsrA protein was most likely located in the cytoplasm.Homology analysis showed that MsrA of V.alginolyticus had high homology with other Vibrio species,and the highest homology with V.alginolyticus.In the prediction of functional domains,MsrA had the function of methionine sulfoxide reduction.In secondary structure prediction,MsrA contained random coils at a proportion of 46.70%,which was the highest.The similarity between the tertiary structure model of MsrA and template Q87SW6.1.A was 89.15%.PTM analysis showed that MsrA protein had many PTM modification sites such as phosphorylation and glycosylation sites.[Conclusions]This study provides some reference value for further study on the role of MsrA in bacterial antioxidant stress.

Molecular Cloning of sodB Gene from Vibrio alginolyticus HY9901 and Its Bioinformatics Analysis

Vibrio alginolyticus is a zoonotic bacterium.A pair of specific primers was designed using the sodB gene sequence of Vibrio alginolyticus HY9901 in order to amplify the full length of the gene by PCR.The results indicated that the total length of the sodB gene was 585 bp and that it could encode 194 amino acids.The predicted amino acid sequence derivation indicated that the molecular weight of the protein was approximately 21.56 kDa,with an isoelectric point of 4.95.Upon prediction of the N-terminal signal peptide structure of the protein,no significant signal peptide cleavage site was observed,indicating that the protein lacked both a signal peptide and a transmembrane region.The amino acid sequence contained an N-glycosylation site,a casein kinase II phosphorylation site,a microsomal C-terminal target signal site,and a manganese and iron superoxide dismutase signal site.The probability of intracytoplasmic localization of the SodB protein was 56.5%,which was analyzed according to the subcellular localization of the protein.The amino acid sequence of the sodB gene of V.alginolyticus exhibited 98%-100%homology to other Vibrio species,clustering into the same subfamily with V.parahaem,indicating a relatively close relationship between them.In the prediction of protein structure,the proportions ofα-helix,random coil,β-sheet,and extended strand were 48.45%,30.41%,5.67%,and 15.46%,respectively.The similarity to template 1dt0.1.A reached 71.58%.A PTM site analysis revealed the presence of phosphorylation,glycosylation,ubiquitination,sumoylation,acetylation,and methylation modification sites,as well as the absence of lactylation modification sites.

1B Specific LMW-GS Primers Cloned a 1D Located Gene from Wheat Cultivar Xiaoyan 22

In the present study, one unique low-molecular-weight glutenin subunit （LMW-GS） gene. LMWXY22-2 （GenBank no. FJ028810）, was isolated from wheat cultivar Xiaoyan 22 （Triticum aestivum L.） by a pair of genomic specific PCR primers for 1B chromosome. Sequence analysis revealed that LMWXY22-2 was composed of 1 364 bp nucleotides, including a 317 bp promotion region and a 1 047 bp coding region which could be translated into a mature protein of 349 amino acids. In spite of a few minor mutations, the sequence of 5＇ untranslated region （UTR）, the coding region, the deduced N- and Cterminus comparisons indicated that LMWXY22-2 belonged to the reported subunits of LMW-m type and type lII group 5, respectively. Inner gene markers for 1D chromosome together with the phylogenetic analysis revealed that this gene was classified into Glu-D3, which was not in agreement with the I B locus-specific primers for LMW genes completely.

Mapping and Functional Analysis of LE Gene in a Lethal Etiolated Rice Mutant at Seedling Stage

An EMS(ethy methanesulfonate)-induced lethal etiolated(le)mutant obtained from the rice variety Zhongjian 100 was characterized by lethal etiolated phenotypes,with significantly reduced levels of chlorophyll a,chlorophyll b,total chlorophyll,and carotenoids.Additionally,the mutant displayed a significantly decreased number of chloroplast grana,along with irregular and less-stacked grana lamellae.The le mutant showed markedly diminished root length,root surface area,and root volume compared with the wild type.It also exhibited significantly lower catalase activity and total protein content,while peroxidase activity was significantly higher.Using the map-based cloning method,we successfully mapped the LE gene to a 48-kb interval between markers RM16107 and RM16110 on rice chromosome 3.A mutation(from T to C)was identified at nucleotide position 692 bp of LOC_Os03g59640(ChlD),resulting in a change from leucine to proline.By crossing HM133(a pale green mutant with a single-base substitution of A for G in exon 10 of ChlD subunit)with a heterozygous line of le(LEle),we obtained two plant lines heterozygous at both the LE and HM133 loci.Among 15 transgenic plants,3 complementation lines displayed normal leaf color with significantly higher total chlorophyll,chlorophyll a,and chlorophyll b contents.The mutation in le led to a lethal etiolated phenotype,which has not been observed in other ChlD mutants.The mutation in the AAA+domain of ChlD disrupted the interaction of ChlDle with ChlI as demonstrated by a yeast two-hybrid assay,leading to the loss of ChlD function and hindering chlorophyll synthesis and chloroplast development.Consequently,this disruption is responsible for the lethal etiolated phenotype in the mutant.

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.

Cloing and Bioinformatics Analysis of ndk Gene from Vibrio alginolyticus

[Objectives]The paper was to clone and analyze bioinformatics of ndk gene from Vibrio alginolyticus.[Methods]A pair of specific primers was designed based on the ndk gene sequence of V.alginolyticus HY9901.The full length of ndk gene was amplified by PCR and bioinformatics analysis was performed.MEGA 5.0 software was used to construct NDK phylogenetic tree by neighbor-joining method.SWISS-MODEL program was used to obtain the three-dimensional structural model of single subunit from NDK protein.[Results]The ndk gene,molecular structural formula C702H1094N192O214S7,was 426 bp in total,encoding 141 amino acids,with the theoretical molecular weight of 15.87199 kD and the theoretical pI value of 5.13.The prediction results of protein subcellular localization,SignalP 5.0,TMHMM Server 2.0 and SoftBerry-Psite showed that NDK mainly existed in the cytoplasm,and the protein was unstable and hydrophobic.There was neither signal peptide cleavage site,nor transmembrane region and KEGG metabolic pathway.The amino acid sequence had two protein kinase C phosphorylation sites,a casein kinaseⅡphosphorylation site,a N-myristoylation site,three microbody C-terminal target signal sites,and a nucleoside diphosphate kinase active site.Homology analysis showed that the NDK of V.alginolyticus had high homology with that of V.diabolicus,with a similarity of 98.58%.Analysis of the structural functional domain revealed that the protein had one NDK structural functional domain.The prediction results of secondary structure showed that theα-helix,random coil,β-sheet and extended strand accounted for 53.19%,28.37%,7.09%and 11.35%,respectively.Analysis of NDK protein via STRING database demonstrated that the proteins interacting with NDK protein were NrdA,NrdB,GmK,CmK,TmK,PyrG,PyrH,RelA,FolE and SpoT.[Conclusions]The study plays a positive role in the prevention and control of vibriosis and the improvement of the current aquaculture environment.

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.

Amplification and Bioinformatics Analysis of h-ns Gene of Vibrio alginolyticus

[Objectives]To amplify the h-ns gene of Vibrio alginolyticus and analyze it by bioinformatics.[Methods]According to the h-ns gene sequence of V.alginolyticus HY9901,a pair of specific primers were designed and amplified by PCR.[Results]The h-ns gene was 408 bp in length and 135 amino acids were encoded.The predicted theoretical protein molecular weight was about 14.98 kD,and the isoelectric point was 4.99.Protein subcellular localization,SignalP 5.0,TMHMM Server 2.0 and SoftBerry-Psite predictions showed that H-NS was located outside the cell membrane,and the protein was unstable and hydrophobic.There was no signal peptide cleavage site,no transmembrane region and no KEGG metabolic pathway.The amino acid sequence contained three phosphorylation sites,one N-terminal myristoylation site and three microsomal C-terminal target signal sites.Using MEGA 5.0,H-NS phylogenetic tree was constructed by ortho-connection method.The results showed that H-NS of V.alginolyticus was closer to H-NS of Vibrio diabolicus.Using SWISS-MODEL,the three-dimensional structure model of H-NS subunit was simulated,which was similar to the crystal structure of Salmonella typhimurium H-NS1-83.[Conclusions]This study lays a foundation for exploring the regulation mechanism of V.alginolyticus H-NS protein on bacterial virulence in the future.

Identification of the Rice Vacuolar ATPase B Subunit Gene and Its Expression Pattern Analysis Under Phosphorus Deficiency

A vacuolar ATPase (V-ATPase.) B subunit gene has been cloned and characterized front a phosphorus starvation induced rice root subtractive cDNA library by suppression subtractive hybridization (SSH) method and RT-PCR amplification. This gene encodes a polypeptide of 487 amino acid residues, containing a conservative ATP binding site and with a molecular weight of 54.06 kD and an isoelectric point of 4.99, southern analysis of the. genomic DNA indicates that V-ATPase B subunit is encoded by a single gene in rice genome. The amino acid homologies of V-ATPase B subunits among different organisms range from 76% to 97% and reveals that the evolution of V-ATPase B subunit is accompanied with the biological evolution. Expression pattern analysis indicated that the maximal expression of V-ATPase B subunit gene occurred at an early stage (6 - 12 h) after phosphorus starvation in roots, and lately stage (24 - 48 It) in leaves. Under phosphorus deficiency, the up-regulated expression of V-ATPase gene was presumed to strengthen the proton transport and provide the required energy to maintain an electrochemical gradient across the tonoplast to facilitate Phosphorus transport.

Cloning of Rabbit Bone Morphogenetic Protein 15 and Its Expression During in vitro Maturation of Rabbit Oocytes

Partial cDNA sequence of rabbit BMP15 was cloned by RT-PCR from rabbit ovaries, showing a similarity of 83%-90% with the BMP15 nucleotide sequences in humans, mice, ovine, sheep, cows and pigs. The expression of BMP15 in rabbit cumulus-oocyte complexs during oocytes in vitro maturation （IVM） was measured by fluorescent quantitative RT-PCR method. BMP 15 was expressed at low levels in immature oocytes and increased to the highest level at 16h of IVM, which coincides with the time of cumulus cell expansion, then declined slowly under IVM cultivation. The expression pattern of BMP 15 suggested that it might be important in cumulus expansion in rabbits.

Study on the Cloning and Isolation of sus scrofa GPX2 Gene by RACE Method

[Objective] Using molecular biotechnology to clone the sus scrofa GPX2 gene. [Method] Using total RNA of sus scrofa duodenum as template, degenerated primer pairs were designed according to the homology alignment analysis of GPX2 gene of human, rat, mouse, dog and cattle. A sus scrofa GPX2 gene sequence of 330 bp was obtained by RT-PCR application method. Primes were designed respectively according to the known sequence, sus scrofa GPX2 gene was isolated and cloned by 3-RACE and 5-RACE method and analyzed the gene sequence. [Result] A mRNA sequence of 924 bp was successfully cloned and isolated in this research. This sequence contained complete 3＇end and had higher sequence homology with human,mouse,cattle and dog GPX2 gene, and there was codon called TGA which encoding Sec on the position of No. 114-116 gene. [Conclusion] Sequence alignment analysis showed that the cloned gene was sus scrofa GPX2 gene （ NCBI GenBank database, the sequence number was D098982）.

Cloning and Bioinformatic Analysis of Cinnamoyl-CoA Reductase Gene (CCR) from Pennisetum purpureum

[Objective] The aim was to clone the cDNA and DNA sequences of the CCR （Cinnamoyl-CoA reductase） gene which involves in lignin biosynthesis, from Pennisetum purpureum, and to make comprehensive analysis on these sequences. [Method] CCR sequences were cloned from P. purpureum by using conventional RT-PCR and RACE （Rapid Amplification of cDNA Ends） methods; and the bioinformatic analyses of the CCR were conducted by means of NCBI, ProtParam ProtScale, TMHMM, TargetP, SignalP, Pfam20.0, Prosite, Swiss-Model, ClustalW2, DNAman, DNAstar and MEGA5. [Result] The cloned PpCCR （P. purpureum CCR） cDNA sequence was 1 316 bp, including a 1 110 bp ORF and 206 bp 3’-UTR. The cloned DNA sequence from PpCCR was 6 133 bp in full-length, containing five exons and four introns. Bioinformatic analysis indicated that PpCCR encoded a polypeptide of 369 amino acids, the secondary structure of which was primarily composed of random coil and α-helix, belonging to NAD-dependent epimerase/dehydratase family, and its co-factor binding sites and substrate binding sites were highly conserved. [Conclusion] DNA and cDNA sequences of CCR gene were obtained from P. purpureum, which had the typical characteristics of other homologous genes. The obtained bioinformatic data provided theoretical references for the further analysis of CCR and better application of P. purpureum in the future.

Cloning and Expression of Wheat Heat-shock Protein 60 (HSP60) Gene in E.coli

[Objective]The aim was to construct the wheat heat-shock protein 60 （HSP60） gene in prokaryotic expression vector and express HSP60 efficiently in E.coli. [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 E.coli 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 E.coli BL21. This will lay the foundation for further study on the functions of the protein and its mechanism.

Cloning of TRP Gene of Bombyx mori

[Objective]The aim was to clone Bombyx mori TRP gene.[Method]The total RNA of Bombyx mori was extracted during its pupal period with Trizol method,and then the TRP gene was cloned by RT-PCR.[Result]The full-length cDNA of TRP gene was successfully obtained,and the ORF fragment（858 bp） of TRP gene was cloned by PCR.[Conclusion]TRP gene of Bombyx mori was cloned for the first time,which could provide solid basis for the study on its function.

Cloning,Sequence Analysis and Amino Acid Structure Prediction of TLR9 Gene from Wild Ovis ammon in Xinjiang

[Objective] The study aimed at cloning and identifying the toll receptor gene 9（TLR9） of wild Ovis ammon in Xinjiang,and predicting its structure and function.[Method] The TLR9 complete sequence of wild Ovis ammon was cloned from its peripheral blood by PCR technology.Then the PCR products were purified by agarose gel electrophoresis and then sequenced.Finally,the structure and function of TLR9 sequence were predicted by molecular biological software.[Result] The complete sequence of TLR9 gene was 3 192 bp in length,encoding 1 064 amino acids with a signal peptide composed of 30 amino acids;the leucine percentage reached as high as 18.5%.The TLR9 amino acid possibly contained three hydrophobic regions,at amino acids 455-475,740-760 and 780-800.The 3-D structure of TLR9 was constructed by the extracellular LRR domain and intracellular TIL domain（Toll/IL IR）.[Conclusion] The characteristics of TLR9 provided theoretical basis for further study on the TLR9 gene of wild Ovis ammon in Xinjiang.

Cloning and Genetic Transformation of OsOle1 Gene in Rice

[Objective] The cloning and transformation of rice OsOle1 gene were conducted in the research.[Method] OsOle1 gene was cloned by RT-PCR.The amplified OsOle1 was then ligased to pCAMBIA 1300 to construct GUS overexpression vector.Then the Agrobacterium-mediated method was used in rice callus transformation.[Result] The full-length of OsOle1 gene was 498 bp and it encoded 189 amino acids.The over-expression vector Ub：：OsOe1-GUS was prepared and transgenic plants were successfully obtained.[Conclusion] The transgenic lines laid the foundation for the function research of OsOle1.

Cloning of Atr MYB Transcription Factor Gene from Acer truncatum

[Objective] Cloning of the AtrMYB transcription factor gene from Acer truncatum was conducted to further explore the red leaf development mechanism and breed cultivars of colored-leaf maple. [Method] The Acer truncatum ‘Luhong No.1＇ cultivar was used as the material for cloning the MYB gene by mean of RTPCR and RACE-PCR. [Results] Sequence analysis showed that the fragment contained a full coding region of 831 bp encoding 276 amino acid residues with a molecular weight of 32.17 kD and a molecular formula C_（1430）H_（14052）N_（2247）O_（406）S_（14）. The gene was named as AtrMYB with a Gen Bank accession number of 1825712. This coded protein had apI of 9.44. The results showed that the AtrMYB exhibited typical features of the R2R3-MYB domain. The AtrMYB was highly homologous with the MYB of other species at nucleotide and amino acid levels. The AtrMYB had no signal peptide, but a nuclear localization signal. The phylogenetic tree showed that the AtrMYB was at the same clade as the MYB from Citrus sinensis. [Conclusion] The AtrMYB was cloned from Acer truncatum ‘Luhong No.1＇ cultivar. These results have provided a foundation for further purification and identification of target protein and function study of the AtrMYB.

Cloning and Sequence Analysis of CmNAC Gene from Cucurbita moschata

[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.

Identification of Senescence-associated Protein DpXTH1 and its Gene Cloning in Dahlia Petals

[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.