共查询到20条相似文献，搜索用时 31 毫秒
1.
C. M. Andrade M. L. P. Tinoco A. F. Rieth F. C. O. Maia F. J. L. Aragão 《Plant pathology》2016,65(4):626-632
Sclerotinia sclerotiorum is a necrotrophic fungus that causes a devastating disease called white mould, infecting more than 450 plant species worldwide. Control of this disease with fungicides is limited, so host plant resistance is the preferred alternative for disease management. However, due to the nature of the disease, breeding programmes have had limited success. A potential alternative to developing necrotrophic fungal resistance is the use of host‐induced gene silencing (HIGS) methods, which involves host expression of dsRNA‐generating constructs directed against genes in the pathogen. In this study, the target gene chosen was chitin synthase (chs), which commands the synthesis of chitin, the polysaccharide that is a crucial structural component of the cell walls of many fungi. Tobacco plants were transformed with an interfering intron‐containing hairpin RNA construct for silencing the fungal chs gene. Seventy‐two hours after inoculation, five transgenic lines showed a reduction in disease severity ranging from 55·5 to 86·7% compared with the non‐transgenic lines. The lesion area did not show extensive progress over this time (up to 120 h). Disease resistance and silencing of the fungal chs gene was positively correlated with the presence of detectable siRNA in the transgenic lines. It was demonstrated that expression of endogenous genes from the very aggressive necrotrophic fungus S. sclerotiorum could be prevented by host induced silencing. HIGS of the fungal chitin synthase gene can generate white mould‐tolerant plants. From a biotechnological perspective, these results open new prospects for the development of transgenic plants resistant to necrotrophic fungal pathogens. 相似文献
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M. Faize L. Burgos L. Faize C. Petri G. Barba‐Espin P. Díaz‐Vivancos M. J. Clemente‐Moreno N. Alburquerque J. A. Hernandez 《Plant pathology》2012,61(5):858-866
The effect of over‐expression in tobacco plants of cytosolic Cu,Zn‐superoxide dismutase (cytsod) and ascorbate peroxidase (cytapx) alone, or in combination, against bacterial wildfire and crown gall diseases, caused by Pseudomonas syringae pv. tabaci and Agrobacterium tumefaciens, respectively, was investigated. Disease tolerance was observed in all the transgenic lines against the two causal agents, with various levels of resistance, with the double transformants (lines 35 and 39) the most resistant against bacterial wild fire. In the case of P. syringae pv. tabaci, disease tolerance and symptom decrease was associated with a lower bacterial population and a higher level of several antioxidant defence enzymes. Transgenic lines also exhibited an enhanced tolerance against A. tumefaciens, with the transgenic line harbouring cytapx (line 51) the most resistant to crown gall disease. However, this was only observed with strain C58 among the three pathogenic strains tested. These results suggest that cytosolic antioxidant defences have a role in increasing tolerance to the oxidative stress caused by some bacterial pathogens, and resistance of these tobacco lines to wildfire disease seems to be independent of tissue necrosis. 相似文献
4.
Soybean is one of the most economically important crops in the world. Its production is affected by several fungal diseases, such as those caused by Fusarium spp., causing significant losses in yield and seed quality. Management interventions are limited, costly, and associated with environmental problems. Host resistance provides a more convenient and cost-effective approach. Host-induced gene silencing (HIGS) has been demonstrated to be an alternative strategy to engineer fungus resistance in plants. We have generated transgenic soybean lines with an intron-hairpin construction in order to express siRNA corresponding to the CYP51B gene from Fusarium oxysporum. Results showed the presence of siRNA corresponding to the F. oxysporum CYP51B gene in both leaves and roots of the transgenic lines. Plants (T3 generation) were challenged against F. oxysporum and F. graminearum. Disease severity was evaluated and revealed resistance to F. oxysporum with one line, named 3.22, presenting no symptoms. In addition, transgenic lines presented better plant development (height and root growth) when compared to the nontransgenic line. Moreover, transgenic lines revealed better development when inoculated with F. oxysporum. 相似文献
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Ping Li Yan Pei Xianchun Sang Yinghua Ling Zhenglin Yang Guanghua He 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(4):533-543
McCHIT1 chitinase (DQ407723), a class I secretory endochitinase from bitter melon (Momordica charantia), had been demonstrated to enhance resistance against Phytophthora nicotianae and Verticillium wilt in transgenic tobacco and cotton. In order to obtain disease-resistant transgenic rice, McCHIT1 was transformed into a restorer line JinHui35 (Oryza sativa subsp. indica) by using the herbicide-resistance gene Bar as the selection marker. Transgenic rice lines and their progenies overexpressing the McCHIT1 gene showed enhanced resistance to Magnaporthe grisea (rice blast) and Rhizoctonia solani (sheath blight), two major fungal pathogens of rice. McCHIT1-transgenic rice confirmed the inheritance of the transgene and disease resistance to the subsequent generation. The T2 transformants exhibited significantly increased tolerance to M. grisea, with a 30.0 to 85.7 reduction in disease index, and R. solani, with a 25.0 to 43.0 reduction in disease index, based on that of the control as 100. These results indicated that over-expression
of the McCHIT1 gene could lead to partial disease reduction against these two important pathogens in transgenic rice. 相似文献
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为明确广谱性抗病毒基因—酵母pac1基因对葡萄B病毒(Grapevine virus B,GVB)的抗性效果,通过农杆菌介导的遗传转化,将pac1基因导入西方烟37B,对转基因植株进行PCR鉴定及Southern blot分析,通过病毒摩擦接种观察症状以及实时荧光定量RT-PCR检测植株体内病毒含量,并对转基因植株抗病性进行初步鉴定。结果表明,目的基因pac1成功导入并整合至西方烟37B基因组,共获得10个转基因株系。不同株系的T1代烟草中阳性植株比例为16.7%~72.7%,表明目的基因可成功遗传到子代。接种病毒后转基因植株普遍延迟发病,但后期症状与非转基因对照相似,其中仅1个转基因株系B6具有不表现典型症状等抗性反应。接种植株病毒含量检测中,所有转基因植株均检测到病毒存在,但表现为抗病的B6株系中病毒含量显著低于非转基因对照,表明该转基因植株虽不能完全抵抗GVB侵染,但对GVB具有耐病性。 相似文献
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The glutamate dehydrogenase gene gdhA increased the resistance of tobacco to glufosinate 总被引：1，自引：0，他引：1
The gene gdhA from Escherichia coli, that encodes a NADPH‐dependent glutamate dehydrogenase (GDH), directs a novel pathway in transgenic plants that allows an increase in ammonium assimilation. Glufosinate leads to plant death by the irreversible inhibition of glutamate synthetase (GS) leading to a disruption of subsequent GS‐related processes resulting in elevated ammonium and disruption of photorespiration. Therefore, it was speculated that the gdhA‐transformed plants may exhibit a novel mechanism of resistance to glufosinate by altered activity of the GDH‐directed pathway(s) and subsequently related processes. Studies were conducted in the greenhouse to evaluate the resistance of tobacco plants containing the gdhA gene to glufosinate. Five tobacco genotype lines were investigated including a non‐transformed control line, a positive control line and three transformed lines with levels of increasing GDH activity directed by the gdhA gene. Plants transformed with the gdhA gene expressed up to six times increased level of resistance (GR50) to glufosinate compared with the non‐transformed control, which is 100 times less resistant than plants transformed with the bar gene. The GDH activity among lines was highly correlated (r2 = 0.9903) with the level of herbicide resistance. Thus, the use of the E. coli gdhA gene in plant transformations can provide an additional mechanism for resistance to glufosinate. 相似文献
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Transgenic plants are controversial for their edible and environmental security. Marker-free transgenic plants can be produced by the construction and transformation of plant expression vectors carrying twin T-DNAs. The construction of plant expression vectors harboring twin T-DNAs and two pathogen-inducible promoters was previously reported. These vector plasmids were introduced into tobacco plants and the transgenic tobacco plants were obtained. In this paper we report that T1 transgenic tobacco seedlings were produced through classical genetics approach. Analysis of the seedlings demonstrated that some of them were marker-free lines. The segregation of exogenous genes in T1 transgenic tobacco seedlings was tested by using two methods. Firstly, the ability of resistance to kanamycin was analyzed in T1 transgenic tobacco seedlings from 14 transgenic plant lines. It was found that the segregation ratio of NPTII genes met well with Mendel’s law in 13 transgenic tobacco lines. So it was deduced that NPTII gene was as a single copy integrated into one of the homologous chromosomes. Then the NPTII genes and uidA genes of 130 T1 transgenic seedlings were detected from the above 13 tobacco lines. The results showed that uidA genes were only detected in 20.77% of the seedlings, NPTII genes were solely detected in 22.31% of the seedlings, but both exogenous genes were in 53.85% of the seedlings. The segregation ratio of the two genes was consistent with the law of independent assortment (9∶3∶3∶1). These results suggested that the selective marker gene had no linkage with the reporter gene and they were segregated independently in the T1 transgenic tobacco plants. This method, as compared with traditional backcross, is confirmed a more easy and rapid way to eliminate the antibiotic resistance gene used as a selective marker in transgenic plants. 相似文献
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Simoni Campos Dias Maria Cristina Mattar da Silva Edson Luis Zangrando Figueira Osmundo Brilhante de Oliveira-Neto Loaiane Alves de Lima Maria Fátima Grossi-de-Sa 《Pesticide biochemistry and physiology》2010,98(1):39-4821
Innumerable proteinaceous α-amylase inhibitors have been isolated and identified from different plant species. Among them, an α-amylase inhibitor gene with bioinsecticidal potential toward Anthonomus grandis (cotton boll weevil) was previously identified in rye seeds (Secale cereale). This cereal inhibitor was expressed in tobacco plants (Nicotiana tabacum) under control of phytohemaglutinin promoter by using Agrobacterium tumefasciens - mediated transformation. Presence of αBIII-rye gene and further protein expression were confirmed by PCR and Western blot analysis, respectively. Immunological assays indicated that the recombinant inhibitor was expressed in concentration range from 0.1% to 0.28% (w:w) of the total protein in tobacco seeds of R0 plants. From 14 independent transformants, five plants with expression levels between 0.20% and 0.28% in seeds were in vitro assayed against A. grandis amylolytic enzymes causing clear inhibition. Moreover, bioassays using transgenic seed flour mixture for artificial diet produced 74% mortality in A. grandis first larval instar. These data suggest that rye inhibitor could be a promising biotechnological tool for produce transgenic cotton plants with an increased resistance to cotton boll weevil. Moreover, αBIII-rye gene should be considered a potential compound for a pyramiding strategy aiming to delay insect-resistance. 相似文献
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将编码大豆凝集素的lec-s基因插入植物表达载体pBI121中,构建植物重组表达质粒pBI121:: lec-s。由根癌土壤杆菌EHA105介导的叶盘法转化烟草,获得了转基因烟草株系。PCR和RT-PCR检测证明lec-s基因已转入烟草植株中。接种烟草花叶病毒（Tobacco mosaic virus,TMV）进行抗病性试验结果表明,转基因烟草叶片上的病斑数显著减少,说明转基因烟草表现出对TMV的抗性。定量RT-PCR检测发现,接种TMV后,抗病防卫基因（PR-1a、GST1、Pal和hsr515）在转基因烟草叶片中显著上调表达。这些结果表明,大豆凝集素基因lec-s转化烟草可对TMV产生抗性,其作用机制可能在于lec-s基因参与了植物的防卫信号通路,诱导了抗病防卫基因在转基因植株体内的表达,增强了植株对TMV的系统抗性。 相似文献
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Luigi Faino Paola Carli Antonino Testa Gennaro Cristinzio Luigi Frusciante Maria Raffaella Ercolano 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(2):233-241
Tomato is challenged by several pathogens which cause loss of production. One such pathogen is the oomycete Phytophthora infestans which is able to attack all the aerial parts of the plant. Although a wide range of resistance sources are available, genetic
control of this disease is not yet successful. Pyramiding R-genes through genetic transformation could be a straightforward
way to produce tomato and potato lines carrying durable resistance to P. infestans. In this work the R1 potato gene was transferred into tomato lines. The tomato transgenic lines were analyzed by using q-RT-PCR
and progeny segregation to determine the gene copy number. To test the hypothesis that R1 represents a specifically regulated R-gene, transgenic tomato plants were inoculated with P. infestans isolate 88133 and IPO. All the plants containing the R1 gene were resistant to the late blight isolate IPO-0 and susceptible to isolate 88133. These results provide evidence for
specific activation of the R1 gene during pathogen challenge. Furthermore, evidence for enhancement of PR-1 gene expression during P. infestans resistance response was obtained. 相似文献
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Hyun-Hwa Lee Jin-Sol Kim Quyen T. N. Hoang Jeong-Il Kim Young Soon Kim 《European journal of plant pathology / European Foundation for Plant Pathology》2018,151(3):811-823
Phytophthora species are soil-borne pathogens that damage plants in both agro- and natural ecosystems. To suppress the devastating pathogen, we generated a root-specific expression system using a specific promoter (pPRP3) conferring elevated expression of the target gene in roots that are very susceptible to soil-borne pathogens. To verify root-specific expression, we compared β-glucuronidase (GUS) expression driven by a constitutive or root-specific promoters in shoots and roots. In histochemical and fluorometric assays, GUS activity was detected in whole tobacco plants when GUS expression was driven by p35S, but was detected only in the roots by pPRP3. We then expressed a pepper defensin (J1–1) gene in tobacco to elucidate its effect on plant resistance. The accumulation of J1–1 was also tissue-specific in transgenic tobacco plants. Finally, transgenic plants carrying GUS or J1–1 genes in combination with p35S or pPRP3 were inoculated with Phytophthora parasitica var. nicotianae and Pythium aphanidermatum. Disease symptoms were significantly suppressed in transgenic plants that accumulated J1–1, regardless of the promoter used. Furthermore, the expression of PR genes was induced in J1–1 transgenic plants, exhibiting much higher levels in p35S-driven J1–1 plants than in pPRP3::J1–1 plants. These results demonstrated that J1–1 transgenic plants were primed for enhanced expression of PR genes, which provided synergistic effects with the defensin for disease resistance. 相似文献
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Owen Wally Jayaraman Jayaraj Zamir Punja 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(3):331-342
Genes encoding an acidic wheat class IV chitinase (383), an acidic wheat β 1,3-glucanase (638) and a rice cationic peroxidase
(POC1) were introduced into ‘Nantes Coreless’ carrot (Daucus carota) by Agrobacterium-mediated transformation. The genes were introduced singly or in various combinations followed by selection imposed by the
herbicide phosphinothricin. Regenerated plantlets were screened for presence and expression of the three transgenes using
PCR, Southern and Northern hybridisations. Eighteen transgenic lines expressing a single transgene and 2 lines each co-expressing
638/383 and 383/POC1 were assessed for resistance to the necrotrophic fungal pathogens Botrytis cinerea and Sclerotinia sclerotiorum. Percentage leaf area diseased was measured 4 and 7 days after inoculation (dai) and compared to non-transformed control
plants. Six lines expressing β-1,3-glucanase 638 alone had no enhanced resistance to B. cinerea at 4 dai and only slight resistance to S. sclerotiorum; there was no effect at 7 dai. Two out of the six lines expressing 383 alone had enhanced tolerance to both pathogens with
a 20–50% reduction in disease development at 7 dai. Two lines co-expressing 638/383 had slight reductions in disease by (10–20%)
similar to that of the lines expressing chitinase 383 alone. Highest levels of disease resistance were seen in transgenic
lines expressing POC1, alone or in combination with chitinase 383. Disease symptoms were slower to develop and symptoms were
reduced by up to 90% for B. cinerea and 70% for S. sclerotiorum. The 383/POC1 co-expressing plants developed disease at levels similar to that of POC1 alone. Petioles of plants over-expressing
POC1 had higher levels of lignin accumulation constitutively compared to control plants, which was greatly enhanced following
inoculation with S. sclerotiorum. These results indicate that peroxidase over-expression can lead to significant disease reduction against necrotrophic pathogens
in transgenic carrot plants. 相似文献
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Plant leucine-rich repeat (LRR) domain-containing proteins are known to play important roles in signaling transduction and defense responses. In sorghum, SbLRR2 is pathogen-inducible gene encoding a simple extracellular LRR protein. Here, we demonstrated an earlier and stronger expression of SbLRR2 in a sorghum resistant genotype in comparison to a susceptible genotype following inoculation with the anthracnose pathogen (Colletotrichum sublineolum). In addition, SbLRR2 expression was found to be induced strongly by methyl-jasmonate treatment. Functional analysis was performed in SbLRR2 over-expression (OE) Arabidopsis plants, which showed enhanced resistance against the necrotrophic pathogens Botrytis cinerea and Alternaria brassicicola. In addition, the OE lines were found to have elevated expression of several jasmonate acid (JA)-associated genes and higher endogenous JA contents. Hence, the SbLRR2-mediated defense responses in transgenic Arabidopsis are likely to be dependent on JA-signaling through increased JA production. On the other hand, the OE lines remained susceptible to Pseudomonas syringae pv. tomato like the wild type plants. Consistently, there was no up-regulation of salicylic acid (SA) defense marker gene expression or SA levels in the OE lines. Our results suggested that SbLRR2 is potentially useful for enhancing resistance against necrotrophic pathogens in transgenic dicot crops. 相似文献
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The hypothesis that dispersin B (DspB), an enzyme from the periodontal pathogen Aggregatibacter actinomycetemcomitans that degrades the extracellular matrix polysaccharide PGA, will inhibit biofilm formation of the soft rot pathogen Pectobacterium carotovorum subsp. carotovorum in infected plants was tested by constitutive expression of DspB in tobacco plants. All the transgenic plants expressed properly folded and active DspB enzyme, although at different expression levels. In virulence assays, even the transgenic plant line D10, which produced a low level of DspB compared to other lines, showed significant resistance against P. carotovorum subsp. carotovorum, suggesting that DspB could be a valuable agent for biological control of P. carotovorum subsp. carotovorum infection in crop plants. 相似文献
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A. Boba A. Kulma K. Kostyn M. Starzycki E. Starzycka J. Szopa 《Physiological and Molecular Plant Pathology》2011,76(1):39-47
Flax engineering to yield increased resistance to pathogens is the goal of this study. Since carotenoids act as antioxidants it is thus postulated that the accumulation of a higher quantity of these compounds in the transgenic plants might improve their resistance to pathogen infection.Our approach was based on the generation of transgenic flax overproducing carotene and analysis of its susceptibility to Fusarium infection. For transformation bacterial gene – crtB was used. As expected, transgenic plants showed increased resistance against pathogen infection.The impact of carotenoids on plant resistance to infection was verified by generation and analysis of transgenic flax with decreased content of carotene. The transgenic plants were obtained by suppression of endogenous flax gene coding for lycopene β-cyclase. Plant analysis revealed decrease in carotene content, however, an unexpected increase in resistance against Fusarium infection was detected. Further analysis of metabolites in the plants revealed that an increase in accumulation of other terpenoids and tocopherols, squalene and menthol were among them. Thus, it is suggested that repression of carotene synthesis results in the redirecting of substrates to other branches of isoprenoids synthesis.We conclude that a general level of antioxidants rather than the presence of any particular compound is the most important factor in resistance of the flax plant to pathogen infection. 相似文献
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Kyutaro Kishimoto Yoko Nishizawa Yutaka Tabei Masami Nakajima Tadaaki Hibi Katsumi Akutsu 《Journal of General Plant Pathology》2004,70(6):314-320
A class III chitinase gene (CHI2) is induced in cucumber plants (Cucumis sativa L.) in response to infection by pathogenic microorganisms. Infection of Botrytis cinerea, causal agent of gray mold disease on cucumber, also induces CHI2 expression. To investigate whether CHI2 is involved in resistance to gray mold disease, transgenic cucumber plants were produced to overexpress the CHI2 gene. One line was analyzed in detail in terms of disease resistance. The transgenic cucumber plant (CC2) constitutively expressed CHI2 and reduced the symptoms of B. cinerea for 4 days after inoculation compared with nontransgenic plants. However, this inhibitory effect was not absolute, and CC2 eventually developed serious disease symptoms. Chitinase activity of the crude extract from CC2 leaves was higher than that from nontransgenic plants. A high-molecular-weight fraction containing CHI2 from CC2 leaves had fungistatic activity against B. cinerea. Interestingly, the low-molecular-weight fraction from CC2 leaves with CHI2 removed also had fungistatic activity against B. cinerea. Not only the introduced chitinase activity but also the endogenous defense reactions activated by overexpression of CHI2 may be involved in the enhanced gray mold disease resistance in CC2. 相似文献