The mRNA Expression Profiles of Five Heat Shock Protein Genes from Frankliniella occidentalis at Different Stages and Their Responses to Temperatures and Insecticides

The westem flower thrips, Frankliniella occidental＆ （Pergande） is a highly invasive pest that is able to exploit many crops across a wide range of environmental conditions. Five full-length cDNAs of heat shock protein （HSP） genes （Fo-HSP90, Fo-HSP70, Fo-HSP60, Fo-HSP40 and Fo-HSP28.9） were cloned from F. occidentalis, and their expression profiles were investigated under conditions of thermal stress and insecticide exposure, and at different stages during development, using real-time quantitative PCR. All five gene sequences showed high similarity to homologs in other species, indicating the conserved fimction of this gene family. HSP60 represents an informative phylogenetic marker at the ordinal taxonomic level within Insecta, but HSP90, which has two homologous copies in Hymenoptera, was not informative. The expression of Fo-HSPs under thermal stress suggests that Fo-HSP90, Fo-HSP70, and Fo-HSP28.9 are inducible by both cold and heat stress, Fo-HSP40 is only heat-inducible, and Fo-HSP60 is thermally insensitive. There were two patterns of cold induction of Fo-HSPs： one is from 0 to 4℃ and the other is around -8℃. All five Fo-HSPs genes were induced by exposure to sublethal concentrations of the insecticide avermectin. The expression of the five Fo-HSPs during different developmental stages suggests that they all play a role in development of F. occidentalis.

Expression of Foreign Gene in Mycobacterium Regulated by Human Mycobacterium Tuberculosis Heat Shock Protein 70 Promoter

The DNA fragments of 150bp length promoter 0f human Mycobacterium(M.) tuberculosis heat shock protein (hsp)7O and 650bp length foreign gene, the Schistosoma japonicum glutathione S-transferase(Sj26GST)gene,were obtained by amplification with polymerase chain reaction. And the 150p DNA sequence upstream initiation codon ATG of the human M. tuberculosis hsp7O promoter that contains the sequence TTGAG and ATCATA which consensus with E. coli promoter's -35 and-10 region respectively, as well as ribosome binding site GGAGG at position-12-8 upstream the ATG were determined by SangerDideoxyribonucleotide-mediated chain-termination method-Then, the human M. tuberculosis hsp70 promoter and Sj26GST cDNA were cloned into E. coli-mycobacteria shuttle plasmid pBCG-2000 to construct E. coli-Mycobacterium expression shuttle plasmid pBCG- Sj26 that can express Sj26GST gene.The M. smegmatis were electroporated and the positivecolonies were selected by kanamycin-The M.smegmatis containing the vector pBCG-Sj26 can be induced by heating and hydrogen peroxide (H2O2) to express GST. The molecular weight of the recombinant GST(rGST) was 26000. The rGST contents that were about 10 percent of the total bacterial protein were analyzed by density scanning after running SDS-PAGE. This study would provide scientific evidences for application of hsp70 promoter in expressing foreign gene in mycobacterium and development of mycobacterium as multiple-valent vectoral vaccine.

Effect of the C.–1388 A>G polymorphism in chicken heat shock transcription factor 3 gene on heat tolerance

Heat stress is one of the main factors that inlfuence poultry production. Heat shock proteins (HSPs) are known to affect heat tolerance. The formation of HSPs is regulated by heat shock transcription factor 3 (HSF3) in chicken. A DNA pool was established for identifying single nucleotide polymorphisms (SNPs) of the chicken HSF3, and 13 SNPs were detected. The bioinformatic analysis showed that 8 SNPs had the capacity to alter the transcription activity of HSF3. The dual luciferase report gene assay showed that there was a signiifcant difference (P<0.01) in the Firelfy luciferase/Renil a luciferase ratio (F/R) of C.–1 703 A>G (S1) and C.–1 388 A>G (S4) sites at the 5′-untranslated region (UTR) of chicken HSF3. The elec-trophoretic mobility shift assay showed that the S4 site was a transcription binding factor. The analysis of the association of the S1 and S4 sites with heat tolerance index revealed that the S4 site was signiifcantly correlated with the CD3+T cel , corticosterone, and T3 levels in Lingshan chickens and with the heterophil/lymphocyte value in White Recessive Rock. These results showed that the S4 site at the 5′ UTR of chicken HSF3 might have an impact on heat tolerance in summer and could be used as a potential marker for the selection of chicken with heat tolerance in the future.

Effects of temperature on the respiratory metabolism,feeding and expression of three heat shock protein genes in Anadara broughtonii

Anadara broughtonii is one of the main commercially important species of shellfish in northern China.A.broughtonii lives in relatively stable subtidal zone where the clam could respond to environmental changes with minimum energy.Therefore,slight fluctuations in water environment may have a great impact on physiological processes such as feeding and metabolism.Large-scale mortality often occurs during the intermediate rearing processes,and high temperatures in summer are considered the leading cause of mortality.To understand the physiological and molecular response patterns of A.broughtonii at high temperatures and to estimate the appropriate metabolism temperature for A.broughtonii,the effects of temperature on the respiratory metabolism and food intake at different growth stages were studied.The response patterns of heat shock protein genes to heat stress and post-stress recovery were also explored.Results show that the temperature and growth stage of A.broughtonii were two important factors affecting metabolism and feeding.The optimum temperature for feeding and physiological activities in each shell-length group was 24℃.The temperature at which the peak metabolic rate occurred in each shell-length group increased with the increase in shell length.With the increase in heat stress,the expression of three heat shock protein genes(Abhsp60,Abhsp70,and Abhsp90)in the tissues of two size groups of A.broughtonii increased significantly when temperature was above 24℃and reached a peak at 30℃.After heat shock at 30℃for 2 h,the expression of the three heat shock protein genes rapidly increased,peaked at 2 h after the heat shock,and then gradually decreased to the level of the control group at 48 h after the heat shock.The three heat shock protein genes respond rapidly to heat stress and can be used as indicators to the cellular stress response in A.broughtonii under an environmental stress.

The polymorphism of heat shock protein 70 genes in Chinese Han population in Fujian province

To understand the polymorphism of the heat shock protein 70 (HSP70) genes in Chinese Han population and to explore the co-relations between HSP70 polymorphism and disease, three polymorphic loci of HSP70 genes in 127 healthy Chinese Han population in Fujian province were analyzed by PCR and restriction enzyme analysis, and the genotypes and allele frequencies of HSP70 in different populations from various area were compared. It was found that the proportions of HSP70-1 genotypes GG, GC and CC among Chinese Han population in Fujian province were 55.1%, 40.2% and 4.7% respectively, while those of HSP70-2 genotypes AA, AG and GG were 44.1%, 48.8% and 6.9% respectively, and those of HSP70-hom genotypes TT, TC and CC were 59.8%, 37.0% and 3.2% respectively. The allele frequencies of G and C in HSP70-1 were 75.2% and 24.8%; those of A and G in HSP70-2 were 68.5% and 31.5% and those of T and C in HSP70-hom were 78.3% and 21.7% respectively. The distribution of the HSP70-1 polymorphisms in Chinese Han population was almost the same as those in Japanese and Mexican populations, but it was rather different from those of American and Spanish populations with a significant differences. Meanwhile, the frequency of GG homozygote in HSP70-1 was significantly higher than those in American and Spanish populations. No significant difference was found in the distribution of HSP70-2 polymorphism between Chinese and Japanese populations, in which the differences among American, Mexican and Spanish populations were quite obvious. The frequency of AA homozygote in HSP70-2 was significantly higher than those in Mexican, American and Spanish populations, while, the distribution of HSP 70-hom genotype and allele frequency in Chinese Han population was almost just the same as those in Japanese and Mexican populations. Furthermore, it was also found that the genotype distribution and allele frequencies of the HSP70 genes in Han population of Fujian province were almost the same as those in Han population in Taiwan, but they were different in certain loci from those of Han population in Wuhan area. It is evident that the distribution of HSP70 gene polymorphisms among Chinese Han population are different from other regions in the world.

Establishment of a tetracycline-off and heat shock-on gene expression system in tobacco

The tetracycline （Tet）-off gene expression regulation system based on the TetR-VP16/Top10 construct has not been widely utilized in plants, for its highly expressed TetR-VP16 activator is toxic to some plants and repeatedly replenishing tetracycline to turn off the constitutively active system is a tedious process. To solve these problems, a Tet-off and heat shock （HS）-on gene expression regulation system was constructed in this study. This system is composed of a chimeric transactivator gene TetR-HSF that is derived from a Tet repressor （TetR） and a HS transcription factor （HSF） controlled by a HS promoter HSP70m, and a Tet operator containing hybrid promoter, Om35S, that drives expression of the β-glucuronidase （GUS） gene. The resultant system yields a GUS expression pattern similar to that of the HSP70m promoter under inducing temperatures and at 35 and 40℃ drives GUS expression to a similar level as the Cauliflower mosaic virus （CaMV） 35S promoter. Further examination revealed that the TetR-HSF and GUS genes were induced by HS, reaching peak expression after 1 and 6 h treatment, respectively, and the HS induction of the expression system could be inhibited by Tet. This system will provide a useful tool for transgenic studies of plants in the laboratory and in the field, including transgene function analysis, agronomic trait improvement, biopharmaceutical protein production and others.

Microarray-based Screening of Target Genes Regulated by Heat Shock Factor AtHsfA1a in Arabidopsis thaliana

[ Objective] This study aimed to screen target genes regulated by heat shock factor AtHsfAla in Arabidopsis thaliana. [ Method] Using AtHsfAla-in- serted mutant athsfala （SALK-068042） and wild-type A. thaliana seedlings as experimental materials, target genes regulated by heat shock factor AtHsfAla were screened by microarray assay. Differentially expressed genes were screened by multiple method. Specific functions of differentially expressed genes were analyzed by gene ontology （GO） analysis. Signal transduction pathways, in which differentia｜ly expressed genes were involved, were analyzed by pathway analysis. Gene-gene interaction network was constructed by Signal-Net. [ Result] A total of 3 672 differentially expressed genes were screened out. Up-regulated differentially expressed genes were involved in 198 functions and 7 signal transduction pathways; down-regulated differentially expressed genes were involved in 94 functions and 10 signal transduction pathways. In the signal transduction network, it was found that cwlNV4 and HXK3 had relatively high ability of mediation; AT1 G14240 and cwlNV4 ex- hibited the most interactions with other genes, which were located in key positions throughout the gene-gene interaction network. [ Conclusion] Heat shock factor AtHsfAla regulates a large number of target genes in A. thaliana.

THE ROLE OF INTRONIC HSE IN THE HEAT SHOCK INDUCED EXPRESSION OF HUMAN hsp 90β GENE

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Construction, Expression and Identification of a Recombinant BCG Vaccine Encoding Human Mycobacterium Tuberculosis Heat Shock Protein 65

Heat shock protein 65 (HSP65) is one of the most important protective immunogens against the tuberculosis infection. The signal sequence of antigen 85B and the whole HSP65 DNA sequence of human Mycobacterium tuberculosis (M. tuberculosis) were amplified from BCG genome and plasmid pCMV-MTHSP65 respectively by polymerase chain reactions (PCR). These two sequences were cloned into the plasmid pBCG-2100 under the control of the promoter of heat shock protein 70 (HSP70) from human M. tuberculosis, yielding the prokaryotic shuttle expression plasmid pBCG-SP-HSP65. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis showed that the two cloned DNA sequences were consistent with those previously reported, and the direction of their inserting into the recombinant was correct and the reading frame had been maintained. The recombinants were electroporated into BCG to construct the recombinant BCG vaccine and induced by heating. The induced expression detected by SDS-PAGE showed that the content of 65 kD protein expressed in recombinant BCG was 35.69 % in total bacterial protein and 74.09 % in the cell lysate supernatants, suggesting that the recombinant HSP65 gene could express in BCG with high efficiency and the expressed proteins were mainly soluble. Western-blot showed that the secretive recombinant proteins could specifically combine with antibody against M. tuberculosis HSP65, indicating that the recombinant proteins possess the biological activity of HSP65.

Influence of High Temperature on the Expression of Arabidopsis Heat Shock Transcription Factor AtHsfA1a

[ Objective] This study ~med to investigate the influence of high temperature on the expression of heat shock transcription factor AtHsfAla in different genotypes of Arabidopsis. [ Method ] Arabidopsis plants overexpressing heat shock transcription factor AtHsfA1 a were used as experimental materials and treated un- der high temperature at 39℃ for 1 rain and 5 min; total RNA of AtI-IsfAla was extracted, and the reverse transcription and amplification were conducted using RT- PCR technology, the amplification products were detected by electrophoresis. [ Result ] The expression levels of AtHsfA1 a in Arabidopsis plants overexpressing heat shock transcription factor AtHsfAla at high temperature and room temperature were higher than wild-type Arabidopsis; the expression levels of AtHsfAla in both wild-type Arab/dops/s and transgenic Arabidopsls plants overexpressing heat shock transcription factor AtHsfAla at high temperature of 39 ~C were higher than that at room temperature of 25 ~C, but the expression levels of AtHsfAla in wild-type Arab/dops/s and transgenic Arab/dops/s plants overexpressing heat shock transcription factor AtHsfAla varied little after high temperature treatment at 39 ~C for 1 rain or 5 rain. [ Conclusion] The expression of AtHsfAla is induced rapidly by high tem- perature, thus regulating the expression of early adversity-resistant genes. This study will lay the foundation demonstrating the mechanism of Arabidopsis heat shock transcription factor AtHsfAla.

Characterization of a TaJ Gene from Wheat

A novel J-domain protein gene was cloned from wheat （Triticum aestivum L.） using RT-PCR technology and named as TaJ. The J-domain protein is defined by the presence of a J-domain. The cDNA of T. aestivum gene, TaJ （GenBank accession number： DQ789026）, was 1263 bp and contained a complete open reading frame （ORF） encoding a J-domain protein of 420 amino acid residues. The predicted amino acid sequence of TaJ possesses three functionally essential domains： the Nterminal J-domain which includes the highly conserved HPD tripeptide, an adjacent domain that is rich in glycine and phenylalanine residues （G/F） and a Cysteine-rich zinc-finger domain with four repeats of CxxCxGxG that is important for protein interactions. The C-terminal of TaJ was -CAQQ, a farnesylation motif. The full-length deduced amino acid sequence of TaJ is highly homologous to J-domain proteins from various plant species. Southern blot analysis indicated that a single copy of TaJ existed in wheat genome. The expression pattern of TaJ performed by real-time PCR demonstrated that heat shock （HS） at 37℃ induced the expression of TaJ rapidly and strongly, but the response of the TaJ gene to cold stress was much slower than that to HS. Tissue-specific expression analysis showed that the expression level of TaJ gene was much higher in leaves than that in roots.

Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

AIM To .investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense.METHODS Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7 d sleep deprivation. RT-PCR,immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70.Ethanol (500 mL@ L 1, I.g.) was used to induce gastric muceea damage.RESULTS RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL@ L-1 ethanol challenge, the ulcer area found in the rats with 7 d sleep deprivation (19.15 ± 4.2) mm2 was significantly lower (P＜0.01) than the corresponding control (53.7 ± 8.1) mm2.CONCLUSION Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.

转录组测序分析外源水杨酸诱导茶树热激蛋白基因的响应

水杨酸是诱导植物抗性机制中重要的信号分子,外源喷施水杨酸能够调控多种防御相关蛋白质,提升农作物的抗病能力。开展外源水杨酸诱导茶树抗性机制的研究能够挖掘抗病基因,为茶树抗病育种提供分子基础。本研究采集外源喷施水杨酸0 h、6 h、12 h、24 h、48 h的茶树叶片进行转录组测序与分析,结果表明,外源喷施水杨酸6 h、12 h、24 h、48 h时茶树叶片内差异表达基因数量分别为9 360个、3 399个、596个、115个,外源水杨酸处理后各时间点均发生差异表达的基因共604个。KEGG功能富集结果显示,处理后6 h时富集于植物激素信号转导、植物-病原菌互作、核糖体、剪接体和碳代谢通路上的差异表达基因数量分别为95个、73个、121个、94个、154个。差异表达基因中有12个热激因子基因、40个热激蛋白基因和12个WRKY家族转录因子基因上调表达。处理48 h后,无上调表达的热激因子基因,但仍有28个热激蛋白基因上调表达。病程相关蛋白基因在检测阶段均上调表达。外源水杨酸的诱导作用在处理6 h时最为明显,并且引起了大量热激蛋白的响应。本研究结果为开展外源水杨酸诱导茶树抗病机制和茶树抗病分子育种研究提供了参考。

ATF6调控生殖相关基因HSPA1L表达的分子机制

目的探究内质网应激活化转录因子6(ATF6)对生殖相关基因热休克蛋白A1样蛋白(HSPA1L)表达的影响并初步阐明其调控分子机制。方法在人胚肾细胞系HEK-293T中转染ATF6过表达质粒,RT-qPCR和Western blot验证过表达效率;利用雄性ATF6敲除小鼠睾丸组织转录物组测序信息,筛选ATF6下游5个生殖相关基因;双荧光素酶报告基因实验选择启动子活性较高的下游基因并检测过表达ATF6对其启动子活性的影响;通过gene-regulation预测ATF6和下游基因启动子可能的结合位点;RT-qPCR和Western blot检测在HEK-293T细胞中过表达ATF6对于下游基因表达的影响;利用凝胶迁移实验(EMSA)确定ATF6与下游基因启动子是否结合。结果转染后HEK-293T细胞中ATF6的mRNA(P<0.001)和蛋白(P<0.05)表达水平明显升高。转录物组测序及双荧光素酶报告基因实验筛选出ATF6下游的生殖相关基因HSPA1L。ATF6能够促进HSPA1L的截短启动子活性(P<0.001)。过表达ATF6后,HSPA1L的表达量明显升高(P<0.001)。差异均有统计学意义。ATF6蛋白能与HSPA1L的启动子DNA序列aagtcgtcac相结合。结论内质网应激的关键分子ATF6通过结合生殖相关基因HSPA1L的启动子调控后者表达水平,这将为预防或治疗与内质网应激(ERS)有关的男性不育的深入研究奠定基础。

Effect of Temperature on Gene Expression in the Pearl Oyster Pinctada fucata

In this study, we examined the effect of elevated temperature on the expression patterns of genes, i.e., nacrein, irr, n16, n19, and hsp70 in the pearl oyster Pinctada fucata. The experiment was carried out at 4 temperatures, i.e., 20℃(ambient, control), 24, 28℃, and 32℃. The expression levels of target genes in P. fucata were assayed at 0, 6, 24, 48, and 96 h via real-time polymerase chain reaction. Results showed that the expression levels of nacrein and irr had no significant variations among different time points below 28℃, but significantly increased over time at 32℃. The expression levels of n16 and n19 did not change markedly at 20℃. The former increased significantly at 6 h and 24 h while the latter substantially decreased during 6–96 h at 24, 28 and 32℃. Among different temperatures, the level of n16 was significantly lower at 20℃ than at other temperatures during 6–96 h, and the level of n19 significantly varied among different temperatures at 48 h and 96 h. The expression level of hsp70 was significantly higher at 32℃ than at 20, 24 and 28℃ at 24 h. These results demonstrated that elevated temperature impacted the physiological processes of P. fucata and potentially influenced its adaptability to thermal stress.

Bioinformatics analysis of microarray data to explore the key genes involved in HSF4 mutation-induced cataract

AIM： To reveal the mechanisms of heat-shock transcription factor 4 （HSF4） mutation-induced cataract.METHODS： GSE22362, including 3 HSF4-null lens and 3 wild-type lens, was obtained from Gene Expression Omnibus database. After data preprocessing, the differentially expressed genes （DEGs） were identified using the limma package. Based on Database for Annotation, Visualization and Integrated Discovery （DAVID） tool, functional and pathway enrichment analyses were performed for the DEGs. Followed by protein-protein interaction （PPI） network was constructed using STRING database and Cytoscape software. Furthermore, the validated microRNA （miRNA）-DEG pairs were obtained from miRWalk2.0 database, and then miRNA-DEG regulatory network was visualized by Cytoscape software. RESULTS： A total of 176 DEGs were identified in HSF4-null lens compared with wild-type lens. In the PPI network, FBJ osteosarcoma oncogene （FOS）, early growth response 1 （EGR1） and heme oxygenase （decycling） 1 （HMOX1） had higher degrees and could interact with each other. Besides, mmu-miR-15a-5p and mmu-miR-26a-5p were among the top 10 miRNAs in the miRNA-DEG regulatory network. Additionally, mmu-miR-26a-5p could target EGR1 in the regulatory network. CONCLUSION： FOS, EGR1, HMOX1, mmu-miR-26a-5p and mmu-miR-15a-5p might function in the pathogenesis of HSF4 mutation-induced cataract.

Cloning and expression of Hsp22.4 gene from Chaetomium globosum

研究在 Chaetomium globosum 在小热吃惊蛋白质(sHSPs ) 的分子的机制上被进行。热吃惊蛋白质 22.4 (Hsp22.4 ) 从 C。globosum 在 Escherichia 关口 i 被克隆并且表示。BlastX 分析揭示了从 C 的 Hsp22.4 基因。globosumshared 在有从 Neurospora 的 Hsp 基因的氨基酸顺序的最高的身份粗糙一，并且在他们之间的身份是 65% 。C。globosum Hsp22.4 基因被插入到 pGEX-4T-2 的富有表达力的向量，重组体原生质标志说出 pGEX-HSP。E。与 pGEX-HSPplasmid 转变的关口 i BL21 被 IPTG 导致，并且表示蛋白质与 SDS 页被分析。50 kD 蛋白质特殊在 E 被表示。关口 i BL21，和结果与期望一致，并且证明 Hsp22.4 基因在 E 被表示了。关口 i。我们的学习为进一步学习 sHSPs 蛋白质的功能做了一个基础。

Constitutively Expressed αB—Crystallin in Heat Schock Transcription Factor 1 Knockout Mice Myocardium

Objective:To invesligate the effects of heat shock transcription factor 1(HSF 1) gene on the constitutively expressed aB-Crystallin(αBC)in mice myocardium.Methods:The expression levels of constitutive αBC in HSF1 knockout(hsf1-/-) and HSF1 wild type (hsf1+/+) mice myocardium were evaluated by western blot and immunohistochemistry.Results:The αBC levels in hsf1-/- and hsf1+/_ were 68.42±4.16,100.00±7.58,respectively(P<0.05,cytosolic fraction),and 20.53±1.01,37.55±1.91,respectively(P<0.05,pellet fraction).The αBC signals decreased significantly in hsf1-/- myocardium when compared with those in hsf1+/+ myocardium stained with fluorescence immunohistochemistry.Conclusion.HSF1 is an important,but not the only factor,which mediates the constitutively expressed αBC.

不同耐药型的结核分枝杆菌hspX基因序列与表达的比较

目的比较不同耐药型的结核分枝杆菌(MTB)热休克蛋白基因hspX序列与表达,初步探讨hspX与MTB的耐药是否存在相关性。方法选取4种一线抗结核药物全部敏感株(S)、同时对异烟肼和利福平耐药(MDR)和一种耐药[单耐利福平(MTB^(R+))、单耐异烟肼(MTB^(H+))、单耐链霉素(MTB^(S+))和单耐乙胺丁醇(MTB^(E+))]的菌株各10株,采用改良的十二烷基苯磺酸钠裂解法和TRIzol法分别提取各组菌株的DNA和RNA,使用特异性引物进行PCR和实时荧光定量PCR确定hspX基因的存在及其表达。对PCR产物进行测序以检查正向和反向的多态性,并用DNAman软件进行与标准株H37Rv序列比对。以敏感菌株(S)组为对照组进行两两对比分析不同耐药型的MTB菌株hspX表达的差异。结果PCR成功获得各组特异性的hspX基因,与H37Rv序列比对具有97%~99%的同一性,无存在明显差异;以相对定量2^(-ΔΔCt)法计算获得S、MDR、MTB^(R+)、MTB^(H+)、MTB^(S+)和MTB^(E+)菌株hspX的表达分别为0.98(0.89,1.23)、1.49(1.10,2.04)、1.41(0.55,2.80)、1.37(0.68,2.71)、0.91(0.59,1.62)和0.70(0.48,1.18)。以敏感菌株(S)组为对照组,不同耐药型菌株组与其比较,hspX表达差异均无统计学意义(P均>0.05)。结论hspX基因在MTB中是保守的。在自然状态下,hspX基因在MTB的耐药性方面无明显相关性。

木薯MeHsfB3a基因的克隆及其抗细菌性枯萎病功能鉴定

木薯是热带地区重要的粮食作物,菜豆黄单胞菌属木薯细菌性枯萎病致病种(Xanthomonas phoseoli pv.manihotis,Xpm)侵染引起的细菌性枯萎病是木薯的重要病害。挖掘、鉴定木薯抗Xpm病原菌侵染的基因,并解析其抗病机制有利于开发木薯抗病种质。植物热激转录因子(heat shock transcription factors,Hsfs)在植物抵御生物胁迫和非生物胁迫的过程中发挥重要作用。本研究利用RT-PCR技术从‘华南8号’(‘SC8’)木薯品种克隆热激蛋白转录因子基因MeHsfB3a的全长。生物信息学分析发现MeHsfB3a含有2个外显子和1个内含子,全长729 bp,编码242个氨基酸,蛋白理论相对分子质量27.9 kDa,理论等电点pI为7.59,理论不稳定系数为56.86,属于不稳定蛋白质,亲水性平均指数-0.880,表明该蛋白水溶性较好,脂溶指数为65.98。亚细胞定位预测该蛋白可定位于细胞核。利用qRT-PCR技术分析发现MeHsfB3a在嫩叶、成熟叶、顶芽、叶柄、块根、须根均有表达,在成熟叶中的表达量最高,在其他器官中的表达量较少。采用Xpm HN11病原菌侵染木薯‘SC8’叶片0、3、6 h和1、3、6 d后分析MeHsfB3a表达,发现1 d以后该基因的表达显著提高。说明MeHsfB3a参与‘SC8’木薯对Xpm HN11病原菌的响应过程。采用VIGS技术沉默木薯‘SC8’的MeHsfB3a基因,该基因沉默效率降低了68.26%~82.44%。接种Xpm HN11病原菌至沉默植株叶片,于接菌0、3、6 d进行发病情况分析,发现沉默植株的病斑面积显著高于对照。本研究鉴定了热击蛋白转录因子基因MeHsfB3a参与木薯抗Xpm HN11病原菌侵染的过程,有助于进一步解析木薯对细菌性枯萎病的抗病机理。