RESUMO
BACKGROUND: The Plutella xylostella PxSDF2L1 gene was previously reported to enhance insect resistance to pathogen at high basal transcription rate. PxSDF2L1 shows similitude with the stromal cell-derived factor 2 (SDF2), an ER stress-induced chaperon protein that is highly conserved throughout animals and plants. The precise biological function of SDF2 is not clear, but its expression is required for innate immunity in plants. Here, we investigate whether a continuous expression of PxSDF2L1 in Nicotiana benthamiana can similarly confer resistance to plant pathogen, particularly, the black shank Phytophthora parasitica var. nicotianae. RESULTS: The N. benthamiana plants were inoculated with agrobacteria transformed with a PVX-based binary vector carrying the PxSDF2L1 gene; similar agroinoculation experiments with a PVX vector carrying the GFP gene were used for controls. In pot trials, agroinfected N. benthamiana plants constitutively expressing PxSDF2L1 showed a significant reduction of stem disease symptoms caused by the inoculation with P. parasitica, compared with controls. CONCLUSIONS: We confirm a role of PxSDF2L1 in resistance to black shank, with a potential application to engineering active resistance against this oomycete in the commercial N. tabacum species and propose its evaluation in other crop families and plant pathogens.
Assuntos
Resistência à Doença , Genes de Insetos , Mariposas/genética , Nicotiana/genética , Phytophthora/fisiologia , Doenças das Plantas/microbiologia , Potexvirus/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Insetos/química , Plantas Geneticamente Modificadas , Proteínas Recombinantes/metabolismoRESUMO
Fungal diseases lead to significant losses in soybean yields and a decline in seed quality; such is the case of the Asian soybean rust and anthracnose caused by Phakopsora pachyrhizi and Colletotrichum truncatum, respectively. Currently, the development of transgenic plants carrying antifungal defensins offers an alternative for plant protection against pathogens. This paper shows the production of transgenic soybean plants expressing the NmDef02 defensin gene using the biolistic delivery system, in an attempt to improve resistance against diseases and reduce the need for chemicals. Transgenic lines were assessed in field conditions under the natural infections of P. pachyrhizi and C. truncatum. The constitutive expression of the NmDef02 gene in transgenic soybean plants was shown to enhance resistance against these important plant pathogens. The quantification of the P. pachyrhizi biomass in infected soybean leaves revealed significant differences between transgenic lines and the non-transgenic control. In certain transgenic lines there was a strong reduction of fungal biomass, revealing a less severe disease. Integration and expression of the transgenes were confirmed by PCR, Southern blot, and qRT-PCR, where the Def1 line showed a higher relative expression of defensin. It was also found that the expression of the NmDef02 defensin gene in plants of the Def1 line did not have a negative effect on the nodulation induced by Bradyrhizobium japonicum. These results indicate that transgenic soybean plants expressing the NmDef02 defensin gene have a substantially enhanced resistance to economically important diseases, providing a sound environmental approach for decreasing yield losses and lowering the burden of chemicals in agriculture.
RESUMO
Peritrophins are associated with structural and functional integrity of peritrophic membranes (PM), structures composed of chitin and proteins. PM lines the insect midgut and has roles in digestion and protection from toxins. We report the full-length cDNA cloning, molecular characterization and functional analysis of SfPER, a novel PM peritrophin A protein, in Spodoptera frugiperda. The predicted amino acid sequence indicated SfPER's domain structure as a CMCMC-type, consisting of a signal peptide and three chitin-binding (C) domains with two intervening mucin-like (M) domains. Phylogenetic analysis determined a close relationship between SfPER and another S. frugiperda PM peritrophin partial sequence. SfPER transcripts were found in larvae and adults but were absent from eggs and pupae. Chitin affinity studies with a recombinant SfPER-C1 peritrophin A-type domain fused to SUMO/His-tag confirmed that SfPER binds to chitin. Western blots of S. frugiperda larval proteins detected different sized variants of SfPER along the PM, with larger variants found towards the posterior PM. In vivo suppression of SfPER expression did not affect susceptibility of larvae to Bacillus thuringiensis toxin, but significantly decreased pupal weight and adult emergence, possibly due to PM structural alterations impairing digestion. Our results suggest SfPER could be a novel target for insect control.
Assuntos
Proteínas de Insetos/metabolismo , Spodoptera/crescimento & desenvolvimento , Spodoptera/metabolismo , Animais , Membrana Celular/metabolismo , Quitina/metabolismo , Comportamento Alimentar , Genes de Insetos , Proteínas de Insetos/química , Proteínas de Insetos/genética , Larva/crescimento & desenvolvimento , Filogenia , Ligação Proteica , Domínios Proteicos , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNA , Spodoptera/genéticaRESUMO
Plants are continuously challenged by pathogens, affecting most staple crops compromising food security. They have evolved different mechanisms to counterattack pathogen infection, including the accumulation of pathogenesis-related (PR) proteins. These proteins have been implicated in active defense, and their overexpression has led to enhanced resistance in nuclear transgenic plants, although in many cases constitutive expression resulted in lesion-mimic phenotypes. We decided to evaluate plastid transformation as an alternative to overcome limitations observed for nuclear transgenic technologies. The advantages include the possibilities to express polycistronic RNAs, to obtain higher protein expression levels, and the impeded gene flow due to the maternal inheritance of the plastome. We transformed Nicotiana tabacum plastids to co-express the tobacco PR proteins AP24 and ß-1,3-glucanase. Transplastomic tobacco lines were characterized and subsequently challenged with Rhizoctonia solani, Peronospora hyoscyami f.sp. tabacina and Phytophthora nicotianae. Results showed that transplastomic plants expressing AP24 and ß-1,3-glucanase are resistant to R. solani in greenhouse conditions and, furthermore, they are protected against P.hyoscyami f.sp. tabacina and P. nicotianae in field conditions under high inoculum pressure. Our results suggest that plastid co- expression of PR proteins AP24 and ß-1,3-glucanase resulted in enhanced resistance against filamentous pathogens.
Assuntos
Bioensaio , Resistência à Doença/genética , Glucana 1,3-beta-Glucosidase/genética , Nicotiana/genética , Nicotiana/microbiologia , Serina Endopeptidases/genética , Ambiente Controlado , Expressão Gênica , Fenótipo , Plantas Geneticamente Modificadas , Nicotiana/imunologiaRESUMO
Multitoxin Bt-crops expressing insecticidal toxins with different modes of action, for example, Cry and Vip, are expected to improve resistance management in target pests. While Cry1A resistance has been relatively well characterized in some insect species, this is not the case for Vip3A, for which no mechanism of resistance has yet been identified. Here we applied HT-SuperSAGE to analyze the transcriptome of the gut tissue of tobacco budworm Heliothis virescens (F.) laboratory-selected for Vip3Aa resistance. From a total of 1 324 252 sequence reads, 5 895 126-bp tags were obtained representing 17 751 nonsingleton unique transcripts (UniTags) from genetically similar Vip3Aa-resistant (Vip-Sel) and susceptible control (Vip-Unsel) strains. Differential expression was significant (≥2.5 fold or ≤0.4; P < 0.05) for 1989 sequences (11.2% of total UniTags), where 420 represented overexpressed (OE) and 1569 underexpressed (UE) genes in Vip-Sel. BLASTN searches mapped 419 UniTags to H. virescens sequence contigs, of which, 416 (106 OE and 310 UE) were unambiguously annotated to proteins in NCBI nonredundant protein databases. Gene Ontology distributed 345 of annotated UniTags in 14 functional categories with metabolism (including serine-type hydrolases) and translation/ribosome biogenesis being the most prevalent. A UniTag homologous to a particular member of the REsponse to PAThogen (REPAT) family was found among most overexpressed, while UniTags related to the putative Vip3Aa-binding ribosomal protein S2 (RpS2) were underexpressed. qRT-PCR of a subset of UniTags validated the HT-SuperSAGE data. This study is the first providing lepidopteran gut transcriptome associated with Vip3Aa resistance and a foundation for future attempts to elucidate the resistance mechanism.
Assuntos
Proteínas de Bactérias , Mariposas/metabolismo , Transcriptoma , Animais , Biblioteca Gênica , Resistência a Inseticidas/genética , Larva/metabolismo , Mariposas/genética , Proteínas Ribossômicas/metabolismo , Serina Proteases/metabolismoRESUMO
OBJECTIVE: The ubiquitous soil pathogen Rhizoctonia solani causes serious diseases in different plant species. Despite the importance of this disease, little is known regarding the molecular basis of susceptibility. SuperSAGE technology and next-generation sequencing were used to generate transcript libraries during the compatible Nicotiana tabacum-R. solani interaction. Also, we used the post-transcriptional silencing to evaluate the function of a group of important genes. RESULTS: A total of 8960 and 8221 unique Tag sequences identified as differentially up- and down-regulated were obtained. Based on gene ontology classification, several annotated UniTags corresponded to defense response, metabolism and signal transduction. Analysis of the N. tabacum transcriptome during infection identified regulatory genes implicated in a number of hormone pathways. Silencing of an mRNA induced by salicylic acid reduced the susceptibility of N. tabacum to R. solani. We provide evidence that the salicylic acid pathway was involved in disease development. This is important for further development of disease management strategies caused by this pathogen.
Assuntos
Perfilação da Expressão Gênica , Nicotiana/genética , Rhizoctonia/genética , Etiquetas de Sequências Expressas , Genes de Plantas , Sequenciamento de Nucleotídeos em Larga Escala , Interferência de RNA , Nicotiana/microbiologiaRESUMO
Huanglongbing (HLB) constitutes the most destructive disease of citrus worldwide, yet no established efficient management measures exist for it. Brassinosteroids, a family of plant steroidal compounds, are essential for plant growth, development and stress tolerance. As a possible control strategy for HLB, epibrassinolide was applied to as a foliar spray to citrus plants infected with the causal agent of HLB, 'Candidatus Liberibacter asiaticus'. The bacterial titers were reduced after treatment with epibrassinolide under both greenhouse and field conditions but were stronger in the greenhouse. Known defense genes were induced in leaves by epibrassinolide. With the SuperSAGE technology combined with next generation sequencing, induction of genes known to be associated with defense response to bacteria and hormone transduction pathways were identified. The results demonstrate that epibrassinolide may provide a useful tool for the management of HLB.
Assuntos
Brassinosteroides/farmacologia , Citrus/microbiologia , Doenças das Plantas/microbiologia , Rhizobiaceae/efeitos dos fármacos , Citrus/efeitos dos fármacos , Folhas de Planta/microbiologiaRESUMO
Many host genes induced during compatible plant-pathogen interactions constitute targets of pathogen virulence factors that act to suppress host defenses. In order to identify Nicotiana tabacum L. genes for pathogen-induced proteins involved in susceptibility to the oomycete Phytophthora parasitica var. nicotianae, we used SuperSAGE technology combined with next-generation sequencing to identify transcripts that were differentially upregulated during a compatible interaction. We identified a pathogen-induced gene (NtPIP) that was rapidly induced only during the compatible interaction. Virus-induced gene silencing of NtPIP reduced the susceptibility of N. tabacum to P. parasitica var. nicotianae. Additionally, transient expression of NtPIP in the resistant species Nicotiana megalosiphon Van Heurck & Mull. Arg. compromised the resistance to P. parasitica var. nicotianae. This pathogen-induced protein is therefore a positive regulator of the susceptibility response against an oomycete pathogen in tobacco.
RESUMO
We have tested whether a gene encoding a polygalacturonase-inhibiting protein (PGIP) protects tobacco against a fungal pathogen (Rhizoctonia solani) and two oomycetes (Phytophthora parasitica var. nicotianae and Peronospora hyoscyami f. sp. tabacina). The trials were performed in greenhouse conditions for R. solani and P. parasitica and in the field for P. hyoscyami. Our results show that expression of PGIP is a powerful way of engineering a broad-spectrum disease resistance.
RESUMO
Rhizoctonia solani Kühn is a soil-borne fungal pathogen that causes disease in a wide range of plants worldwide. Strains of the fungus are traditionally grouped into genetically isolated anastomosis groups (AGs) based on hyphal anastomosis reactions. This article summarizes aspects related to the infection process, colonization of the host and molecular mechanisms employed by tobacco plants in resistance against R. solani diseases. TAXONOMY: Teleomorph: Thanatephorus cucumeris (Frank) Donk; anamorph: Rhizoctonia solani Kühn; Kingdom Fungi; Phylum Basidiomycota; Class Agaricomycetes; Order Cantharellales; Family Ceratobasidiaceae; genus Thanatephorus. IDENTIFICATION: Somatic hyphae in culture and hyphae colonizing a substrate or host are first hyaline, then buff to dark brown in colour when aging. Hyphae tend to form at right angles at branching points that are usually constricted. Cells lack clamp connections, but possess a complex dolipore septum with continuous parenthesomes and are multinucleate. Hyphae are variable in size, ranging from 3 to 17 µm in diameter. Although the fungus does not produce any conidial structure, ellipsoid to globose, barrel-shaped cells, named monilioid cells, 10-20 µm wide, can be produced in chains and can give rise to sclerotia. Sclerotia are irregularly shaped, up to 8-10 mm in diameter and light to dark brown in colour. DISEASE SYMPTOMS: Symptoms in tobacco depend on AG as well as on the tissue being colonized. Rhizoctonia solani AG-2-2 and AG-3 infect tobacco seedlings and cause damping off and stem rot. Rhizoctonia solani AG-3 causes 'sore shin' and 'target spot' in mature tobacco plants. In general, water-soaked lesions start on leaves and extend up the stem. Stem lesions vary in colour from brown to black. During late stages, diseased leaves are easily separated from the plant because of severe wilting. In seed beds, disease areas are typically in the form of circular to irregular patches of poorly growing, yellowish and/or stunted seedlings. RESISTANCE: Knowledge is scarce regarding the mechanisms associated with resistance to R. solani in tobacco. However, recent evidence suggests a complex response that involves several constitutive factors, as well as induced barriers controlled by multiple defence pathways. MANAGEMENT: This fungus can survive for many years in soil as mycelium, and also by producing sclerotia, which makes the management of the disease using conventional means very difficult. Integrated pest management has been most successful; it includes timely fungicide applications, crop rotation and attention to soil moisture levels. Recent developments in biocontrol may provide other tools to control R. solani in tobacco.
Assuntos
Nicotiana/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Rhizoctonia/fisiologia , Imunidade Inata/imunologia , Doenças das Plantas/imunologia , Rhizoctonia/classificaçãoRESUMO
Plant defensins are small cysteine-rich peptides that inhibit the growth of a broad range of microbes. In this article, we describe NmDef02, a novel cDNA encoding a putative defensin isolated from Nicotiana megalosiphon upon inoculation with the tobacco blue mould pathogen Peronospora hyoscyami f.sp. tabacina. NmDef02 was heterologously expressed in the yeast Pichia pastoris, and the purified recombinant protein was found to display antimicrobial activity in vitro against important plant pathogens. Constitutive expression of NmDef02 gene in transgenic tobacco and potato plants enhanced resistance against various plant microbial pathogens, including the oomycete Phytophthora infestans, causal agent of the economically important potato late blight disease, under greenhouse and field conditions.
Assuntos
Defensinas/genética , Imunidade Inata , Nicotiana/genética , Doenças das Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Dados de Sequência Molecular , Peronospora , Phytophthora , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Solanum tuberosum/genética , Solanum tuberosum/imunologia , Nicotiana/imunologiaRESUMO
SfT6 has been identified in a subtracted cDNA library of Spodoptera frugiperda larval midgut transcripts as a serine-protease gene downregulated within 24 h of intoxication with Bacillus thuringiensis Cry1Ca1 protein. In the present study, the specific role of SfT6 during Cry1Ca1 intoxication was investigated by RT-PCR and in vivo RNA interference. Quantitative real-time RT-PCR analysis showed SfT6 mRNA levels in the midgut tissue were significantly reduced after injecting or feeding 4th-instar larvae with specific long-size dsRNA. Gut juice-mediated in vitro protoxin activation and susceptibility for Cry1Ca1 were investigated in Sft6-knockdown larvae and compared with control treated with nonspecific dsRNA. Our results demonstrate SfT6 plays a determinant role in Cry1Ca1 toxicity against S. frugiperda since a decreased expression caused a reduced protoxin activation by larval gut juice and reduced susceptibility of insects to toxin in bioassays. We propose SfT6 downregulation occurring at the early stages of Cry1Ca1 intoxication is part of a complex and multifaceted defensive mechanism triggered in the insect gut to withstand B. thuringiensis pathogenesis.
Assuntos
Bacillus thuringiensis , Proteínas de Bactérias/toxicidade , Toxinas Bacterianas/toxicidade , Endotoxinas/toxicidade , Proteínas Hemolisinas/toxicidade , Precursores de Proteínas/toxicidade , Interferência de RNA , Serina Endopeptidases/genética , Spodoptera/efeitos dos fármacos , Spodoptera/genética , Animais , Toxinas de Bacillus thuringiensis , Sistema Digestório/metabolismo , Técnicas de Silenciamento de Genes , Genes de Insetos , Interações Hospedeiro-Patógeno , Larva/enzimologia , Larva/genética , Larva/microbiologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Mensageiro/análise , Serina Endopeptidases/metabolismo , Spodoptera/enzimologia , Spodoptera/metabolismo , Spodoptera/microbiologiaRESUMO
Blue mould [Peronospora hyoscyami f. sp. tabacina (Adam) Skalicky 1964] is one of the most important foliar diseases of tobacco that causes significant losses in the Americas, south-eastern Europe and the Middle East. This review summarizes the current knowledge of the mechanisms employed by this oomycete pathogen to colonize its host, with emphasis on molecular aspects of pathogenicity. In addition, key biochemical and molecular mechanisms involved in tobacco resistance to blue mould are discussed. TAXONOMY: Kingdom: Chromista (Straminipila); Phylum: Heterokontophyta; Class: Oomycete; Order: Peronosporales; Family: Peronosporaceae; Genus: Peronospora; Species: Peronospora hyoscyami f. sp. tabacina. DISEASE SYMPTOMS: The pathogen typically causes localized lesions on tobacco leaves that appear as single, or groups of, yellow spots that often coalesce to form light-brown necrotic areas. Some of the leaves exhibit grey to bluish downy mould on their lower surfaces. Diseased leaves can become twisted, such that the lower surfaces turn upwards. In such cases, the bluish colour of the diseased plants becomes quite conspicuous, especially under moist conditions when sporulation is abundant. Hence the name of the disease: tobacco blue mould. INFECTION PROCESS: The pathogen develops haustoria within plant cells that are thought to establish the transfer of nutrients from the host cell, and may also act in the delivery of effector proteins during infection. RESISTANCE: Several defence responses have been reported to occur in the Nicotiana tabacum-P. hyoscyami f. sp. tabacina interaction. These include the induction of pathogenesis-related genes, and a correlated increase in the activities of typical pathogenesis-related proteins, such as peroxidases, chitinases, beta-1,3-glucanases and lipoxygenases. Systemic acquired resistance is one of the best characterized tobacco defence responses activated on pathogen infection.
Assuntos
Nicotiana/parasitologia , Peronospora/patogenicidade , Doenças das Plantas , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Nicotiana/imunologiaRESUMO
To identify Nicotiana tabacum genes involved in resistance and susceptibility to Rhizoctonia solani, suppression subtractive hybridization was used to generate a cDNA library from transcripts that are differentially expressed during a compatible and incompatible interaction. This allowed the isolation of a protein kinase cDNA that was down-regulated during a compatible and up-regulated during an incompatible interaction. Quantitative RT-PCR analysis of this gene confirmed the differential expression patterns between the compatible and incompatible interactions. Over-expression of this gene in tobacco enhanced the resistance to damping-off produced by an aggressive R. solani strain. Furthermore, silencing of this protein kinase gene reduced the resistance to a non-aggressive R. solani strain. A set of reported tobacco-resistant genes were also evaluated in tobacco plants over-expressing and silencing the protein kinase cDNA. Several genes previously associated with resistance in tobacco, like manganese superoxide dismutase, Hsr203J, chitinases and phenylalanine ammonia-lyase, were up-regulated in tobacco plants over-expressing the protein kinase cDNA. Potentially, the protein kinase gene could be used to engineer resistance to R. solani in tobacco cultivars susceptible to this important pathogen.
Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Nicotiana/genética , Doenças das Plantas/genética , Proteínas Quinases/genética , Rhizoctonia/fisiologia , Sequência de Aminoácidos , Biomassa , DNA Complementar/genética , Dados de Sequência Molecular , Doenças das Plantas/microbiologia , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Alinhamento de Sequência , Nicotiana/enzimologia , Nicotiana/microbiologiaRESUMO
A glutathione S-transferase gene was amplified from cDNA of Nicotiana tabacum roots infected with Phytophthora parasitica var. nicotianae. The gene was cloned in sense and anti-sense orientation to an RNAi vector for induced gene silencing, and reduced expression of the gene was detected by RT-PCR. A statistically significant increase in resistance of N. tabacum to infection following gene silencing was found for glutathione S-transferase-silenced plants compared with control plants. Some defense genes were up-regulated in glutathione S-transferase-silenced plants during the interaction with the pathogen. This is the first evidence of the role of glutathione S-transferase as negative regulator of defense response.
Assuntos
Glutationa Transferase/genética , Nicotiana/genética , Phytophthora , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Clonagem Molecular , Inativação GênicaRESUMO
The use of Bacillus thuringiensis Cry delta-endotoxins as bioinsecticides is threatened by the possibility of pest resistance. Determining transcriptional profiles of midgut cells early in Cry toxin poisoning is crucial for understanding the biochemical and molecular aspects of insect detoxification and for sustained use of such toxins. In this study, transcriptional responses of midgut cells from Spodoptera frugiperda third-instar larvae following treatment with Cry1Ca were investigated. Suppression subtractive hybridization (SSH) on insect midguts dissected at different time intervals during the first 24h of exposure to a sublethal concentration of Cry1Ca was used to isolate and identify S. frugiperda gut genes that change in expression on intoxication. After differential screening by membrane-based hybridization, 86 cDNA fragments were selected, sequenced, and analyzed in databases using BLASTN/BLASTX. The cDNA collection comprised a repertoire of genes mainly associated with metabolism, defence and oxidative stress. The expression of a subset of these genes was further investigated. Northern blot analysis confirmed the differential expression patterns between intoxicated and control larvae. The transcript accumulation rate at six different times taken after the initiation of the intoxication point was also examined. Differential expression of most genes examined was detected within 15 min after toxin challenge, where defence and oxidative stress-related genes were transcriptionally enhanced and metabolic-related genes were repressed.
Assuntos
Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Spodoptera/efeitos dos fármacos , Animais , Toxinas de Bacillus thuringiensis , Bioensaio , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Biblioteca Gênica , Larva/efeitos dos fármacosRESUMO
In order to identify tobacco (Nicotiana megalosiphon) genes involved in broad-spectrum resistance to tobacco blue mold (Peronospora hyoscyami f. sp. tabacina), suppression subtractive hybridization was used to generate cDNA from transcripts that are differentially expressed during an incompatible interaction. After differential screening by membrane-based hybridization, clones corresponding to 182 differentially expressed genes were selected, sequenced, and analyzed. The cDNA collection comprised a broad repertoire of genes associated with various processes. Northern blot analysis of a subset of these genes confirmed the differential expression patterns between the compatible and incompatible interaction. Subsequent virus-induced gene silencing (VIGS) of four genes that were found to be differentially induced was pursued. While VIGS of a lipid transfer protein gene or a glutamate decarboxylase gene in Nicotiana megalosiphon did not affect blue mold resistance, silencing of an EIL2 transcription factor gene and a glutathione synthetase gene was found to compromise the resistance of Nicotiana megalosiphon to P. hyoscyami f. sp. tabacina. Potentially, these genes can be used to engineer resistance in blue mold-susceptible tobacco cultivars.
Assuntos
Glutationa Sintase/metabolismo , Nicotiana/metabolismo , Nicotiana/microbiologia , Peronospora/fisiologia , Doenças das Plantas/microbiologia , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Glutationa Sintase/genética , Dados de Sequência Molecular , Mutação , Folhas de Planta/microbiologia , Nicotiana/enzimologia , Nicotiana/genética , Fatores de Transcrição/genéticaRESUMO
Among the abiotic stresses, the availability of water is the most important factor that limits the productive potential of higher plants. The identification of novel genes, determination of their expression patterns, and the understanding of their functions in stress adaptation is essential to improve stress tolerance. Amplified fragment length polymorphism analysis of cDNA was used to identify rice genes differentially expressed in a tolerant rice variety upon water-deficit stress. In total, 103 transcript-derived fragments corresponding to differentially induced genes were identified. The results of the sequence comparison in BLAST database revealed that several differentially expressed TDFs were significantly homologous to stress regulated genes/proteins isolated from rice or other plant species. Most of the transcripts identified here were genes related to metabolism, energy, protein biosynthesis, cell defence, signal transduction, and transport. New genes involved in the response to water-deficit stress in a tolerant rice variety are reported here.