A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified. The mutant expressed hypersensitive response （HR）-like symptoms throughout its whole life from the first ...A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified. The mutant expressed hypersensitive response （HR）-like symptoms throughout its whole life from the first leaf to the flag leaf, without pathogen invasion. Initiation of the lesions was induced by light under natural summer field conditions. Expression of pathogenesis-related genes including PAL, PO-C1, POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type （WT）. Disease reaction to Xanthomonas oryzae pv. oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested. An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions. Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene, tentatively named spl HM47 , flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4. Ten open reading frames are predicted, and all of them are expressed proteins. Isolation and validation of the putative genes are currently underway.展开更多
In Arabidopsis, systemic acquired resistance （SAR） is established beyond the initial infection by a pathogen or is directly induced by treatment with salicylic acid （SA） or its functional analogs, 2,6-dichloroison...In Arabidopsis, systemic acquired resistance （SAR） is established beyond the initial infection by a pathogen or is directly induced by treatment with salicylic acid （SA） or its functional analogs, 2,6-dichloroisonicotinic acid （INA） and benzothiadiazole （BTH）. NPR1 protein is considered the master regulator of SAR in both SA signal sensing and transduction. In wheat （Triticum aesfivum） and barley （Hordeum vulgare）, both pathogen infection and BTH treatment can induce broad-spectrum resistance to various diseases, including powdery mildew, leaf rust, Fusarium head blight, etc. However, three different types of SAR-like responses including acquired resistance （AR）, systemic immunity （SI）, and BTH-induced resistance （BIR） seem to be achieved by activating different gene pathways. Recent research on wheat and barley NPR1 homologs in AR and SI has provided the initial clue for understanding the mechanism of SAR in these two plant species. In this review, the specific features ofAR, Si, and BIR in wheat and barley were summarized and compared with that of SAR in model plants of Arabidopsis and rice. Research updates on downstream genes of SAR, including pathogenesis-related （PR） and BTH-induced genes, were highlighted.展开更多
植物MAPKs(mitogen-activated protein kinases)在多种生物和非生物胁迫中起重要作用。课题组前期克隆了甘蓝型油菜BnMAPK1基因,并获得BnMAPK1超量表达植株。本文以甘蓝型油菜中油821DH系为对照,以超量表达BnMAPK1的转基因油菜为试材,...植物MAPKs(mitogen-activated protein kinases)在多种生物和非生物胁迫中起重要作用。课题组前期克隆了甘蓝型油菜BnMAPK1基因,并获得BnMAPK1超量表达植株。本文以甘蓝型油菜中油821DH系为对照,以超量表达BnMAPK1的转基因油菜为试材,采用离体叶片接种的方法,测定染病叶片病斑的大小及病斑周围叶片的草酸含量,并用qRT-PCR检测转基因植株4个病程相关蛋白(OXO、Cu/Zn-SOD、PR2、PR3)编码基因在核盘菌胁迫下的相对表达动态变化。结果表明,甘蓝型油菜BnMAPK1超量表达可显著抑制核盘菌对离体叶片的侵染,控制染病叶片内草酸毒素的积累,可能可以解除核盘菌对OXO表达的负调控,使另外3个与病程相关蛋白基因(Cu/Zn-SOD、PR2、PR3)表达上调。表明BnMAPK1超量表达可有效提高油菜菌核病抗性。展开更多
Verticillium wilt, a devastating disease in cotton caused by Verticillium dahliae, reduces cotton quality and yield. Heterotrimeric GTP-binding proteins, consisting of Ga, Gb, and Gc subunits, transducers of receptor ...Verticillium wilt, a devastating disease in cotton caused by Verticillium dahliae, reduces cotton quality and yield. Heterotrimeric GTP-binding proteins, consisting of Ga, Gb, and Gc subunits, transducers of receptor signaling, function in a wide range of biological events. However, the function of Ga proteins in the regulation of defense responses in plants is largely unexplored, except for a few reports on model species. In the present study, a cotton G-protein a-subunit-encoding gene(GhGPA) was isolated from Verticillium wilt-resistant Gossypium hirsutum(upland cotton) cv. ND601. GhGPA transcription was up-regulated under V. dahliae stress, with higher expression in tolerant than in susceptible cotton cultivars.Subcellular localization revealed GhGPA to be located in the plasma membrane. GhGPA shows high(85.0%) identity with Arabidopsis AT2 G26300(AtGPA1), and AtGPA1 gpa1-4 mutants displayed susceptibility to V. dahliae. Ectopic expression of GhGPA successfully restored the resistance of Arabidopsis gpa1-4 mutants to Verticillium wilt and made them more resistant than the wild type. Overexpression of GhGPA in Arabidopsis markedly increased the resistance and resulted in dramatic up-regulation of pathogenesis-related(PR) genes and increased in H2 O2 accumulation and salicylic acid(SA) and jasmonic acid(JA) contents. However, suppressing GhGPA expression via virus-induced gene silencing(VIGS)increased susceptibility to Verticillium wilt, down-regulated the expression of PR and marker genes in SA and JA signaling pathways, and reduced H2 O2 content. The contents of SA and JA in Arabidopsis gpa1-4 and VIGS cotton were lower than those in the wild type and empty-vector control. However,GhGPA-overexpressing Arabidopsis contained more SA and JA than the wild type when inoculated with V. dahliae. Thus, GhGPA plays a vital role in Verticillium wilt resistance by inducing SA and JA signaling pathways and regulating the production of reactive oxygen species. These findings not only broaden our knowledge about the biologi展开更多
Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and su...Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and susceptible genotypes following pathogen infection or insect infestation. Quantitative real-time PCR （qRT-PCR） revealed that PR1, PR2, PR3, PR5, PR6, PR8, PR9, and PR15 appeared to be induced or suppressed independently in response to Fusarium, YDV aphid-transmitted or Hf during the interactions. The PR gene（s） essential to defense against one organism may play little or no role in defense against another pathogen or pest, suggesting the alternative mechanisms may be involved in different interactions of wheat- Fusarium, wheat-YDV aphid-transmitted and wheat-Hf. However, strong up- or down-regulation of PRl2 and PR14 encoding low molecular membrane acting protein, defensin and lipid transfer protein （LTP）, respectively, had been detected after either pathogen infection or insect infestation, therefore showed broad responses to pathogens and insects. It was postulated that low molecular proteins such as defensins and LTPs might play a role in the early stages of pathogenesis in the signaling process that informs plants about the attack from biotic stresses. In addition, a synergistic action between different PR genes might exist in plants to defense certain pathogens and insects on the basis of comprehensive expression profiling of various pathogenesis-related genes revealed by qRT-PCR in this study.展开更多
Background: Urinary tract infection caused by Escherichia coli is a frequently observed condition both in humans and animals. Uropathogenic E. coli (UPEC) has been shown to have a pathogenicity island that enables the...Background: Urinary tract infection caused by Escherichia coli is a frequently observed condition both in humans and animals. Uropathogenic E. coli (UPEC) has been shown to have a pathogenicity island that enables them to infect the urinary tract. Because there is little information about the presence of UPEC-associated virulent genes in animal isolates this work was carried out with the intent to enhance the understanding about the strains of E.coli that cause infections in animals. Results: We screened 21 E. coli strains isolated causing urinary tract infection in domestic animals. Primers were designed to amplify urinary infection-associated genes. Nine genes, papA, tcpC, fyuA, tpbA, Lma, hylA, picU, tonB, and flicC were then amplified and sequenced. Different from the human isolate CFT073, all the animals E. coli lack some of the pathogenesis-associated genes. Genes encoding for proteins used to scavenge iron appear not to be so necessary during animal infections as they are in human infection. In further investigation of phenotypic properties, it was observed that animal UPECs have significantly more impaired ability to form biofilms than human UPEC strain. Conclusions: This study identified significant differences between human and animal UPECs. This may have its roots in the fact that it is difficult to determine if an animal has symptoms. Future studies will focus on some of the observations.展开更多
[Objective] It is to clone broad-spectrum anti-disease gene NPR1 and to construct its protein expression vector.[Method] First to extract total RNA of Arabidopsis thaliana and design relevant primers,and then the meth...[Objective] It is to clone broad-spectrum anti-disease gene NPR1 and to construct its protein expression vector.[Method] First to extract total RNA of Arabidopsis thaliana and design relevant primers,and then the method of reverse transcription PCR was adopted to clone.With the method of enzyme digestion and ligation,this gene will be directed into protein expression vector.[Result] After relevant testing,NPR1 was inserted into vector pMXB10 to obtain pMXB10-NPR1 protein expression vector.[Conclusion] Protein expression vector including NPR1 was successfully constructed.展开更多
基金supported by the National Hi-Tech Research and Development Program of China(2011AA10A101 and 2012AA101102)the State Key Laboratory of Rice Biology(ZZKT200801)
文摘A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified. The mutant expressed hypersensitive response （HR）-like symptoms throughout its whole life from the first leaf to the flag leaf, without pathogen invasion. Initiation of the lesions was induced by light under natural summer field conditions. Expression of pathogenesis-related genes including PAL, PO-C1, POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type （WT）. Disease reaction to Xanthomonas oryzae pv. oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested. An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions. Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene, tentatively named spl HM47 , flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4. Ten open reading frames are predicted, and all of them are expressed proteins. Isolation and validation of the putative genes are currently underway.
基金the National Natural Science Foundation of China (31701776, 31301649)the Young Talents Project of Hebei Education Department, China (BJ2016028)
文摘In Arabidopsis, systemic acquired resistance （SAR） is established beyond the initial infection by a pathogen or is directly induced by treatment with salicylic acid （SA） or its functional analogs, 2,6-dichloroisonicotinic acid （INA） and benzothiadiazole （BTH）. NPR1 protein is considered the master regulator of SAR in both SA signal sensing and transduction. In wheat （Triticum aesfivum） and barley （Hordeum vulgare）, both pathogen infection and BTH treatment can induce broad-spectrum resistance to various diseases, including powdery mildew, leaf rust, Fusarium head blight, etc. However, three different types of SAR-like responses including acquired resistance （AR）, systemic immunity （SI）, and BTH-induced resistance （BIR） seem to be achieved by activating different gene pathways. Recent research on wheat and barley NPR1 homologs in AR and SI has provided the initial clue for understanding the mechanism of SAR in these two plant species. In this review, the specific features ofAR, Si, and BIR in wheat and barley were summarized and compared with that of SAR in model plants of Arabidopsis and rice. Research updates on downstream genes of SAR, including pathogenesis-related （PR） and BTH-induced genes, were highlighted.
文摘植物MAPKs(mitogen-activated protein kinases)在多种生物和非生物胁迫中起重要作用。课题组前期克隆了甘蓝型油菜BnMAPK1基因,并获得BnMAPK1超量表达植株。本文以甘蓝型油菜中油821DH系为对照,以超量表达BnMAPK1的转基因油菜为试材,采用离体叶片接种的方法,测定染病叶片病斑的大小及病斑周围叶片的草酸含量,并用qRT-PCR检测转基因植株4个病程相关蛋白(OXO、Cu/Zn-SOD、PR2、PR3)编码基因在核盘菌胁迫下的相对表达动态变化。结果表明,甘蓝型油菜BnMAPK1超量表达可显著抑制核盘菌对离体叶片的侵染,控制染病叶片内草酸毒素的积累,可能可以解除核盘菌对OXO表达的负调控,使另外3个与病程相关蛋白基因(Cu/Zn-SOD、PR2、PR3)表达上调。表明BnMAPK1超量表达可有效提高油菜菌核病抗性。
基金supported by the National Key Research and Development Program of China(2016YFD0101006)the China Agricultural Research System(CARS15-03)the Outstanding Youth Found of Hebei Province(C2019204365)。
文摘Verticillium wilt, a devastating disease in cotton caused by Verticillium dahliae, reduces cotton quality and yield. Heterotrimeric GTP-binding proteins, consisting of Ga, Gb, and Gc subunits, transducers of receptor signaling, function in a wide range of biological events. However, the function of Ga proteins in the regulation of defense responses in plants is largely unexplored, except for a few reports on model species. In the present study, a cotton G-protein a-subunit-encoding gene(GhGPA) was isolated from Verticillium wilt-resistant Gossypium hirsutum(upland cotton) cv. ND601. GhGPA transcription was up-regulated under V. dahliae stress, with higher expression in tolerant than in susceptible cotton cultivars.Subcellular localization revealed GhGPA to be located in the plasma membrane. GhGPA shows high(85.0%) identity with Arabidopsis AT2 G26300(AtGPA1), and AtGPA1 gpa1-4 mutants displayed susceptibility to V. dahliae. Ectopic expression of GhGPA successfully restored the resistance of Arabidopsis gpa1-4 mutants to Verticillium wilt and made them more resistant than the wild type. Overexpression of GhGPA in Arabidopsis markedly increased the resistance and resulted in dramatic up-regulation of pathogenesis-related(PR) genes and increased in H2 O2 accumulation and salicylic acid(SA) and jasmonic acid(JA) contents. However, suppressing GhGPA expression via virus-induced gene silencing(VIGS)increased susceptibility to Verticillium wilt, down-regulated the expression of PR and marker genes in SA and JA signaling pathways, and reduced H2 O2 content. The contents of SA and JA in Arabidopsis gpa1-4 and VIGS cotton were lower than those in the wild type and empty-vector control. However,GhGPA-overexpressing Arabidopsis contained more SA and JA than the wild type when inoculated with V. dahliae. Thus, GhGPA plays a vital role in Verticillium wilt resistance by inducing SA and JA signaling pathways and regulating the production of reactive oxygen species. These findings not only broaden our knowledge about the biologi
基金financial support by the National Basic Research Program of China (2009CB118301)the Transgenic Special Item of China (2011ZX08002-004 and 2011ZX08009-003)+1 种基金the National Natural Science Foundation of China (31071405)the National High-Tech R&D Program of China (2011AA100102 and 2012AA101105)
文摘Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and susceptible genotypes following pathogen infection or insect infestation. Quantitative real-time PCR （qRT-PCR） revealed that PR1, PR2, PR3, PR5, PR6, PR8, PR9, and PR15 appeared to be induced or suppressed independently in response to Fusarium, YDV aphid-transmitted or Hf during the interactions. The PR gene（s） essential to defense against one organism may play little or no role in defense against another pathogen or pest, suggesting the alternative mechanisms may be involved in different interactions of wheat- Fusarium, wheat-YDV aphid-transmitted and wheat-Hf. However, strong up- or down-regulation of PRl2 and PR14 encoding low molecular membrane acting protein, defensin and lipid transfer protein （LTP）, respectively, had been detected after either pathogen infection or insect infestation, therefore showed broad responses to pathogens and insects. It was postulated that low molecular proteins such as defensins and LTPs might play a role in the early stages of pathogenesis in the signaling process that informs plants about the attack from biotic stresses. In addition, a synergistic action between different PR genes might exist in plants to defense certain pathogens and insects on the basis of comprehensive expression profiling of various pathogenesis-related genes revealed by qRT-PCR in this study.
文摘Background: Urinary tract infection caused by Escherichia coli is a frequently observed condition both in humans and animals. Uropathogenic E. coli (UPEC) has been shown to have a pathogenicity island that enables them to infect the urinary tract. Because there is little information about the presence of UPEC-associated virulent genes in animal isolates this work was carried out with the intent to enhance the understanding about the strains of E.coli that cause infections in animals. Results: We screened 21 E. coli strains isolated causing urinary tract infection in domestic animals. Primers were designed to amplify urinary infection-associated genes. Nine genes, papA, tcpC, fyuA, tpbA, Lma, hylA, picU, tonB, and flicC were then amplified and sequenced. Different from the human isolate CFT073, all the animals E. coli lack some of the pathogenesis-associated genes. Genes encoding for proteins used to scavenge iron appear not to be so necessary during animal infections as they are in human infection. In further investigation of phenotypic properties, it was observed that animal UPECs have significantly more impaired ability to form biofilms than human UPEC strain. Conclusions: This study identified significant differences between human and animal UPECs. This may have its roots in the fact that it is difficult to determine if an animal has symptoms. Future studies will focus on some of the observations.
基金Supported by project of Beijing Municipal Education Commission(KM200910020014)Project of Sand Control Department,Beijing Municipal Landscape Greening Bureau(2008)~~
文摘[Objective] It is to clone broad-spectrum anti-disease gene NPR1 and to construct its protein expression vector.[Method] First to extract total RNA of Arabidopsis thaliana and design relevant primers,and then the method of reverse transcription PCR was adopted to clone.With the method of enzyme digestion and ligation,this gene will be directed into protein expression vector.[Result] After relevant testing,NPR1 was inserted into vector pMXB10 to obtain pMXB10-NPR1 protein expression vector.[Conclusion] Protein expression vector including NPR1 was successfully constructed.
