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1.
Mol Plant Microbe Interact ; 37(3): 277-289, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38148279

RESUMO

The poplar rust fungus Melampsora larici-populina is part of one of the most devastating group of fungi (Pucciniales) and causes important economic losses to the poplar industry. Because M. larici-populina is a heteroecious obligate biotroph, its spread depends on its ability to carry out its reproductive cycle through larch and then poplar parasitism. Genomic approaches have identified more than 1,000 candidate secreted effector proteins (CSEPs) from the predicted secretome of M. larici-populina that are potentially implicated in the infection process. In this study, we selected CSEP pairs (and one triplet) among CSEP gene families that share high sequence homology but display specific gene expression profiles among the two distinct hosts. We determined their subcellular localization by confocal microscopy through expression in the heterologous plant system Nicotiana benthamiana. Five out of nine showed partial or complete chloroplastic localization. We also screened for potential protein interactors from larch and poplar by yeast two-hybrid assays. One pair of CSEPs and the triplet shared common interactors, whereas the members of the two other pairs did not have common targets from either host. Finally, stromule induction quantification revealed that two pairs and the triplet of CSEPs induced stromules when transiently expressed in N. benthamiana. The use of N. benthamiana eds1 and nrg1 knockout lines showed that CSEPs can induce stromules through an eds1-independent mechanism. However, CSEP homologs shared the same impact on stromule induction and contributed to discovering a new stromule induction cascade that can be partially and/or fully independent of eds1. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Basidiomycota , Populus , Nicotiana/genética , Basidiomycota/genética , Transcriptoma , Plastídeos , Populus/genética , Populus/microbiologia , Doenças das Plantas/microbiologia
2.
Plant Cell Rep ; 43(7): 172, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874775

RESUMO

KEY MESSAGE: The heat stress transcription factor HSFA2e regulates both temperature and drought response via hormonal and secondary metabolism alterations. High temperature and drought are the primary yield-limiting environmental constraints for staple food crops. Heat shock transcription factors (HSF) terminally regulate the plant abiotic stress responses to maintain growth and development under extreme environmental conditions. HSF genes of subclass A2 predominantly express under heat stress (HS) and activate the transcriptional cascade of defense-related genes. In this study, a highly heat-inducible HSF, HvHSFA2e was constitutively expressed in barley (Hordeum vulgare L.) to investigate its role in abiotic stress response and plant development. Transgenic barley plants displayed enhanced heat and drought tolerance in terms of increased chlorophyll content, improved membrane stability, reduced lipid peroxidation, and less accumulation of ROS in comparison to wild-type (WT) plants. Transcriptome analysis revealed that HvHSFA2e positively regulates the expression of abiotic stress-related genes encoding HSFs, HSPs, and enzymatic antioxidants, contributing to improved stress tolerance in transgenic plants. The major genes of ABA biosynthesis pathway, flavonoid, and terpene metabolism were also upregulated in transgenics. Our findings show that HvHSFA2e-mediated upregulation of heat-responsive genes, modulation in ABA and flavonoid biosynthesis pathways enhance drought and heat stress tolerance.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico , Hordeum , Reguladores de Crescimento de Plantas , Proteínas de Plantas , Plantas Geneticamente Modificadas , Hordeum/genética , Hordeum/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Resposta ao Choque Térmico/genética , Reguladores de Crescimento de Plantas/metabolismo , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Clorofila/metabolismo , Estresse Fisiológico/genética , Metabolismo Secundário/genética , Redes e Vias Metabólicas/genética , Resistência à Seca
3.
Plant Mol Biol ; 111(4-5): 379-392, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36790538

RESUMO

Plants have developed strategies to deal with the great variety of challenges they are exposed to. Among them, common targets are the regulation of transcription and translation to finely modulate protein levels during both biotic and abiotic stresses. Increasing evidence suggests that ribosomes are highly adaptable modular supramolecular structures which remodel to adapt to stresses. Each Arabidopsis thaliana ribosome consists of approximately 81 distinct ribosomal proteins (RPs), each of which is encoded by two to seven genes. To investigate the identity of ribosomal proteins of the small subunit (RPS) and of the large subunit (RPL) as well as ribosomes-associated proteins, we analysed by LC/MS/MS immunopurified ribosomes from A. thaliana leaves treated with isonicotinic acid (INA), an inducer of plant innate immunity. We quantified a total of 2084 proteins. 165 ribosome-associated proteins showed increased abundance while 52 were less abundant. Of the 52 identified RPS (from a possibility of 104 encoding genes), 15 were deregulated. Similarly, from the 148 possible RPL, 80 were detected and 9 were deregulated. Our results revealed potential candidates involved in innate immunity that could be interesting targets for functional genomic studies.


Assuntos
Arabidopsis , Arabidopsis/genética , Plântula/metabolismo , Espectrometria de Massas em Tandem , Ácidos Isonicotínicos/metabolismo , Proteínas Ribossômicas/genética
4.
Plant Biotechnol J ; 21(4): 726-741, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36593511

RESUMO

Under field conditions, plants are often simultaneously exposed to several abiotic and biotic stresses resulting in significant reductions in growth and yield; thus, developing a multi-stress tolerant variety is imperative. Previously, we reported the neofunctionalization of a novel PNP family protein, Putranjiva roxburghii purine nucleoside phosphorylase (PRpnp) to trypsin inhibitor to cater to the needs of plant defence. However, to date, no study has revealed the potential role and mechanism of either member of this protein group in plant defence. Here, we overexpressed PRpnp in Citrus aurantifolia which showed nuclear-cytoplasmic localization, where it functions in maintaining the intracellular purine reservoir. Overexpression of PRpnp significantly enhanced tolerance to salt, oxidative stress, alkaline pH, drought and two pests, Papilio demoleus and Scirtothrips citri in transgenic plants. Global gene expression studies revealed that PRpnp overexpression up-regulated differentially expressed genes (DEGs) related to ABA- and JA-biosynthesis and signalling, plant defence, growth and development. LC-MS/MS analysis validated higher endogenous ABA and JA accumulation in transgenic plants. Taken together, our results suggest that PRpnp functions by enhancing the endogenous ABA and JA, which interact synergistically and it also inhibits trypsin proteases in the insect gut. Also, like other purine salvage genes, PRpnp also regulates CK metabolism and increases the levels of CK-free bases in transgenic Mexican lime. We also suggest that PRpnp can be used as a potential candidate to develop new varieties with improved plant vigour and enhanced multiple stress resistance.


Assuntos
Ácido Abscísico , Citrus , Ácido Abscísico/metabolismo , Cromatografia Líquida , Purina-Núcleosídeo Fosforilase/genética , Purina-Núcleosídeo Fosforilase/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Espectrometria de Massas em Tandem , Plantas Geneticamente Modificadas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Citrus/genética , Secas
5.
Plant Cell ; 30(10): 2594-2615, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30150314

RESUMO

Infection of plant cells by RNA viruses leads to the generation of organelle-like subcellular structures that contain the viral replication complex. During Turnip mosaic virus (TuMV) infection of Nicotiana benthamiana, the viral membrane protein 6K2 plays a key role in the release of motile replication vesicles from the host endoplasmic reticulum (ER). Here, we demonstrate that 6K2 contains a GxxxG motif within its predicted transmembrane domain that is vital for TuMV infection. Replacement of the Gly with Val within this motif inhibited virus production, and this was due to a relocation of the viral protein to the Golgi apparatus and the plasma membrane. This indicated that passage of 6K2 through the Golgi apparatus is a dead-end avenue for virus infection. Impairing the fusion of transport vesicles between the ER and the Golgi apparatus by overexpression of the SNARE Sec22 protein resulted in enhanced intercellular virus movement. Likewise, expression of nonfunctional, Golgi-located synaptotagmin during infection enhanced TuMV intercellular movement. 6K2 copurified with VTI11, a prevacuolar compartment SNARE protein. An Arabidopsis thaliana vti11 mutant was completely resistant to TuMV infection. We conclude that TuMV replication vesicles bypass the Golgi apparatus and take an unconventional pathway that may involve prevacuolar compartments/multivesicular bodies for virus infection.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/virologia , Interações Hospedeiro-Patógeno/fisiologia , Nicotiana/virologia , Potyvirus/fisiologia , Proteínas Qb-SNARE/metabolismo , Motivos de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Brefeldina A/farmacologia , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/virologia , Complexo de Golgi/metabolismo , Complexo de Golgi/virologia , Mutagênese Sítio-Dirigida , Folhas de Planta/virologia , Plantas Geneticamente Modificadas , Potyvirus/patogenicidade , Proteínas Qb-SNARE/genética , Proteínas SNARE/genética , Proteínas SNARE/metabolismo , Sinaptotagminas/metabolismo , Nicotiana/efeitos dos fármacos , Nicotiana/genética , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo , Replicação Viral/fisiologia
6.
BMC Genomics ; 21(1): 35, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924161

RESUMO

BACKGROUND: RNA sequencing allows the measuring of gene expression at a resolution unmet by expression arrays or RT-qPCR. It is however necessary to normalize sequencing data by library size, transcript size and composition, among other factors, before comparing expression levels. The use of internal control genes or spike-ins is advocated in the literature for scaling read counts, but the methods for choosing reference genes are mostly targeted at RT-qPCR studies and require a set of pre-selected candidate controls or pre-selected target genes. RESULTS: Here, we report an R-based pipeline to select internal control genes based solely on read counts and gene sizes. This novel method first normalizes the read counts to Transcripts per Million (TPM) and then excludes weakly expressed genes using the DAFS script to calculate the cut-off. It then selects as references the genes with lowest TPM covariance. We used this method to pick custom reference genes for the differential expression analysis of three transcriptome sets from transgenic Arabidopsis plants expressing heterologous fungal effector proteins tagged with GFP (using GFP alone as the control). The custom reference genes showed lower covariance and fold change as well as a broader range of expression levels than commonly used reference genes. When analyzed with NormFinder, both typical and custom reference genes were considered suitable internal controls, but the custom selected genes were more stably expressed. geNorm produced a similar result in which most custom selected genes ranked higher (i.e. were more stably expressed) than commonly used reference genes. CONCLUSIONS: The proposed method is innovative, rapid and simple. Since it does not depend on genome annotation, it can be used with any organism, and does not require pre-selected reference candidates or target genes that are not always available.


Assuntos
Perfilação da Expressão Gênica/métodos , Genes Essenciais/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Algoritmos
7.
Planta ; 252(4): 53, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32945950

RESUMO

MAIN CONCLUSION: Overexpressing a heat shock factor gene (TaHsfA6bT) from wheat provides thermotolerance in barley by constitutive expression of heat and other abiotic stress-response genes. Temperature is one of the most crucial abiotic factors defining the yield potential of temperate cereal crops, such as barley. The regulators of heat shock response (HSR), heat stress transcription factors (Hsfs), modulate the transcription level of heat-responsive genes to protect the plants from heat stress. In this study, an Hsf from wheat (TaHsfA6b) is overexpressed in barley for providing thermotolerance. Transgenic barley lines overexpressing TaHsfA6b showed improvement in thermotolerance. The constitutive overexpression of a TaHsfA6b gene upregulated the expression of major heat shock proteins and other abiotic stress-responsive genes. RNA-seq and qRT-PCR analysis confirmed the upregulation of Hsps, chaperonins, DNAJ, LEA protein genes, and genes related to anti-oxidative enzymes in transgenic lines. Excessive generation and accumulation of reactive oxygen species (ROS) occurred in wild-type (WT) plants during heat stress; however, the transgenic lines reflected improved ROS homeostasis mechanisms, showing lesser ROS accumulation under high temperature. No negative phenotypic changes were observed in overexpression lines. These results suggest that TaHsfA6b is a regulator of HSR and its overexpression altered the expression patterns of some main stress-related genes and enhanced the thermotolerance of this cereal crop.


Assuntos
Expressão Gênica , Hordeum , Proteínas de Plantas , Termotolerância , Fatores de Transcrição , Triticum , Resposta ao Choque Térmico/genética , Hordeum/genética , Hordeum/metabolismo , Temperatura Alta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Termotolerância/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Triticum/genética
8.
J Exp Bot ; 71(21): 6844-6855, 2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-32090252

RESUMO

In plant-pathogen interactions, expression and localization of effectors in the aqueous apoplastic region play a crucial role in the establishment or suppression of pathogen development. Silicon (Si) has been shown to protect plants in several host-pathogen interactions, but its mode of action remains a source of debate. Its deposition in the apoplastic area of plant cells suggests that it might interfere with receptor-effector recognition. In this study, soybean plants treated or not with Si were inoculated with Phytophthora sojae and differences in the ensuing infection process were assessed through different microscopy techniques, transcript analysis of effector and defense genes, and effector (Avr6) localization through immunolocalization and fluorescence labeling. In plants grown without Si, the results showed the rapid (4 d post-inoculation) host recognition by P. sojae through the development of haustorium-like bodies, followed by expression and release of effectors into the apoplastic region. In contrast, Si treatment resulted in limited pathogen development, and significantly lower expression and presence of Avr6 in the apoplastic region. Based on immunolocalization and quantification of Avr6 through fluorescence labeling, our results suggest that the presence of Si in the apoplast interferes with host recognition and/or limits receptor-effector interactions, which leads to an incompatible interaction.


Assuntos
Phytophthora , Doenças das Plantas , Proteínas de Plantas/genética , Silício , Glycine max/genética
9.
Plant Mol Biol ; 101(4-5): 343-354, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31621005

RESUMO

KEY MESSAGE: Short review focussing on the role and targeting of vacuolar substructure in plant immunity and pathogenesis. Plants lack specialized immune cells, therefore each plant cell must defend itself against invading pathogens. A typical plant defense strategy is the hypersensitive response that results in host cell death at the site of infection, a process largely regulated by the vacuole. In plant cells, the vacuole is a vital organelle that plays a central role in numerous fundamental processes, such as development, reproduction, and cellular responses to biotic and abiotic stimuli. It shows divergent membranous structures that are continuously transforming. Recent technical advances in visualization and live-cell imaging have significantly altered our view of the vacuolar structures and their dynamics. Understanding the active nature of the vacuolar structures and the mechanisms of vacuole-mediated defense responses is of great importance in understanding plant-pathogen interactions. In this review, we present an overview of the current knowledge about the vacuole and its internal structures, as well as their role in plant-microbe interactions. There is so far limited information on the modulation of the vacuolar structures by pathogens, but recent research has identified the vacuole as a possible target of microbial interference.


Assuntos
Interações Hospedeiro-Patógeno , Imunidade Vegetal , Plantas/ultraestrutura , Vacúolos/ultraestrutura , Biomarcadores/metabolismo , Morte Celular , Membranas Intracelulares/imunologia , Membranas Intracelulares/microbiologia , Membranas Intracelulares/ultraestrutura , Proteínas de Plantas/metabolismo , Plantas/imunologia , Plantas/microbiologia , Vacúolos/imunologia , Vacúolos/microbiologia
10.
New Phytol ; 222(3): 1190-1206, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30554421

RESUMO

Contents Summary 1190 I. Introduction 1190 II. Rust fungi: a diverse and serious threat to agriculture 1191 III. The different facets of rust life cycles and unresolved questions about their evolution 1191 IV. The biology of rust infection 1192 V. Rusts in the genomics era: the ever-expanding list of candidate effector genes 1195 VI. Functional characterization of rust effectors 1197 VII. Putting rusts to sleep: Pucciniales research outlooks 1201 Acknowledgements 1202 References 1202 SUMMARY: Rust fungi (Pucciniales) are the largest group of plant pathogens and represent one of the most devastating threats to agricultural crops worldwide. Despite the economic importance of these highly specialized pathogens, many aspects of their biology remain obscure, largely because rust fungi are obligate biotrophs. The rise of genomics and advances in high-throughput sequencing technology have presented new options for identifying candidate effector genes involved in pathogenicity mechanisms of rust fungi. Transcriptome analysis and integrated bioinformatics tools have led to the identification of key genetic determinants of host susceptibility to infection by rusts. Thousands of genes encoding secreted proteins highly expressed during host infection have been reported for different rust species, which represents significant potential towards understanding rust effector function. Recent high-throughput in planta expression screen approaches (effectoromics) have pushed the field ahead even further towards predicting high-priority effectors and identifying avirulence genes. These new insights into rust effector biology promise to inform future research and spur the development of effective and sustainable strategies for managing rust diseases.


Assuntos
Basidiomycota/fisiologia , Agricultura , Basidiomycota/genética , Evolução Biológica , Proteínas Fúngicas/metabolismo , Genômica , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
11.
Int J Mol Sci ; 20(18)2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31487924

RESUMO

Chaga (Inonotus obliquus) is a medicinal fungus used in traditional medicine of Native American and North Eurasian cultures. Several studies have demonstrated the medicinal properties of chaga's bioactive molecules. For example, several terpenoids (e.g., betulin, betulinic acid and inotodiol) isolated from I. obliquus cells have proven effectiveness in treating different types of tumor cells. However, the molecular mechanisms and regulation underlying the biosynthesis of chaga terpenoids remain unknown. In this study, we report on the optimization of growing conditions for cultured I. obliquus in presence of different betulin sources (e.g., betulin or white birch bark). It was found that better results were obtained for a liquid culture pH 6.2 at 28 °C. In addition, a de novo assembly and characterization of I. obliquus transcriptome in these growth conditions using Illumina technology was performed. A total of 219,288,500 clean reads were generated, allowing for the identification of 20,072 transcripts of I. obliquus including transcripts involved in terpenoid biosynthesis. The differential expression of these genes was confirmed by quantitative-PCR. This study provides new insights on the molecular mechanisms and regulation of I. obliquus terpenoid production. It also contributes useful molecular resources for gene prediction or the development of biotechnologies for the alternative production of terpenoids.


Assuntos
Basidiomycota/genética , Genes Fúngicos , Transcriptoma , Triterpenos/metabolismo , Basidiomycota/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica
12.
Genome ; 61(5): 329-336, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29514010

RESUMO

Lobster mushroom is a wild edible mushroom with potential commercial value. It is the product resulting of the infection, most commonly of Russula brevipes, by Hypomyces lactifluorum. This study undertook quantitative polymerase chain reaction analysis of tissues sampled at different infection stages to investigate R. brevipes - H. lactifluorum interaction. We followed the colonization of R. brevipes sporocarps by H. lactifluorum that leads to the edible lobster mushrooms. In parallel, metabolomics analysis was performed to detect differences in metabolite profile among non-infected R. brevipes sporocarp and lobster mushroom. The results show that H. lactifluorum DNA is not restricted to the margin but is distributed relatively evenly across the sporocarp of the lobster mushroom. Russula brevipes DNA was also present throughout the sporocarp but was less abundant at the margins and increased inwards. Russula brevipes DNA also declined as the infection progressed. Metabolomics analysis revealed that the flesh of lobster mushroom, which remains identical in appearance to the flesh of the host, undergoes transformation that alters its metabolite profile, most notably of lipids and terpene compounds. These results define a parasitic relationship between the two species that entails a decline of R. brevipes DNA and a modification of its metabolite profile.


Assuntos
Agaricales/metabolismo , DNA Fúngico/genética , Interações Hospedeiro-Patógeno , Hypocreales/metabolismo , Metaboloma , Agaricales/genética , Agaricales/crescimento & desenvolvimento , Alcaloides/metabolismo , Aminoácidos/metabolismo , Cromatografia Líquida de Alta Pressão , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Hypocreales/patogenicidade , Metabolismo dos Lipídeos , Lipídeos/química , Fenóis/metabolismo , Reação em Cadeia da Polimerase , Terpenos/metabolismo
13.
Mol Plant Microbe Interact ; 29(4): 247-57, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26713351

RESUMO

In both animals and plants, messenger (m)RNA export has been shown to contribute to immune response regulation. The Arabidopsis nuclear protein MOS11, along with the nucleoporins MOS3/Nup96/SAR3 and Nup160/SAR1 are components of the mRNA export machinery and contribute to immunity mediated by nucleotide binding leucine-rich repeat immune receptors (NLR). The human MOS11 ortholog CIP29 is part of a small protein complex with three additional members: the RNA helicase DDX39, ALY, and TAF15b. We systematically assessed the biological roles of the Arabidopsis homologs of these proteins in toll interleukin 1 receptor-type NLR (TNL)-mediated immunity using reverse genetics. Although mutations in ALY and DDX39 did not result in obvious defects, taf15b mutation partially suppressed the autoimmune phenotypes of a gain-of-function TNL mutant, snc1. An additive effect on snc1 suppression was observed in mos11-1 taf15b snc1 triple mutant plants, suggesting that MOS11 and TAF15b have independent functions. TAF15b-GFP fusion protein, which fully complemented taf15b mutant phenotypes, localized to nuclei similarly to MOS11. However, it was also targeted to cytosolic granules identified as processing bodies. In addition, we observed no change in SNC1 mRNA levels, whereas less SNC1 protein accumulated in taf15b mutant, suggesting that TAF15b contributes to SNC1 homeostasis through posttranscriptional mechanisms. In summary, this study highlights the importance of posttranscriptional RNA processing mediated by TAF15b in the regulation of TNL-mediated immunity.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Processamento Pós-Transcricional do RNA/imunologia , Transporte Ativo do Núcleo Celular , Arabidopsis/citologia , Arabidopsis/imunologia , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Genes Reporter , Complexos Multiproteicos , Mutação , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Fenótipo , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Plântula/citologia , Plântula/genética , Plântula/imunologia
15.
PLoS Genet ; 6(12): e1001250, 2010 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-21203492

RESUMO

Nucleocytoplasmic trafficking is emerging as an important aspect of plant immunity. The three related pathways affecting plant immunity include Nuclear Localization Signal (NLS)-mediated nuclear protein import, Nuclear Export Signal (NES)-dependent nuclear protein export, and mRNA export relying on MOS3, a nucleoporin belonging to the Nup107-160 complex. Here we report the characterization, identification, and detailed analysis of Arabidopsis modifier of snc1, 11 (mos11). Mutations in MOS11 can partially suppress the dwarfism and enhanced disease resistance phenotypes of snc1, which carries a gain-of-function mutation in a TIR-NB-LRR type Resistance gene. MOS11 encodes a conserved eukaryotic protein with homology to the human RNA binding protein CIP29. Further functional analysis shows that MOS11 localizes to the nucleus and that the mos11 mutants accumulate more poly(A) mRNAs in the nucleus, likely resulting from reduced mRNA export activity. Epistasis analysis between mos3-1 and mos11-1 revealed that MOS11 probably functions in the same mRNA export pathway as MOS3, in a partially overlapping fashion, before the mRNA molecules pass through the nuclear pores. Taken together, MOS11 is identified as a new protein contributing to the transfer of mature mRNA from the nucleus to the cytosol.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Núcleo Celular/metabolismo , RNA Mensageiro/metabolismo , RNA de Plantas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transporte Ativo do Núcleo Celular , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Transporte Biológico , Núcleo Celular/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , RNA Mensageiro/genética , RNA de Plantas/genética , Proteínas de Ligação a RNA/genética
16.
Biomolecules ; 13(7)2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37509195

RESUMO

Upon exposure to biotic and abiotic stress, plants have developed strategies to adapt to the challenges imposed by these unfavorable conditions. The energetically demanding translation process is one of the main elements regulated to reduce energy consumption and to selectively synthesize proteins involved in the establishment of an adequate response. Emerging data have shown that ribosomes remodel to adapt to stresses. In Arabidopsis thaliana, ribosomes consist of approximately eighty-one distinct ribosomal proteins (RPs), each of which is encoded by two to seven genes. Recent research has revealed that a mutation in a given single RP in plants can not only affect the functions of the RP itself but can also influence the properties of the ribosome, which could bring about changes in the translation to varying degrees. However, a pending question is whether some RPs enable ribosomes to preferentially translate specific mRNAs. To reveal the role of ribosomal proteins from the small subunit (RPS) in a specific translation, we developed a novel approach to visualize the effect of RPS silencing on the translation of a reporter mRNA (GFP) combined to the 5'UTR of different housekeeping and defense genes. The silencing of genes encoding for NbRPSaA, NbRPS5A, and NbRPS24A in Nicotiana benthamiana decreased the translation of defense genes. The NbRACK1A-silenced plant showed compromised translations of specific antioxidant enzymes. However, the translations of all tested genes were affected in NbRPS27D-silenced plants. These findings suggest that some RPS may be potentially involved in the control of protein translation.


Assuntos
Arabidopsis , Proteínas Ribossômicas , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , RNA Mensageiro/genética , Biossíntese de Proteínas , Subunidades Ribossômicas Menores/genética , Subunidades Ribossômicas Menores/metabolismo
17.
Front Plant Sci ; 14: 1261180, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37810374

RESUMO

The use of protoplasts in plant biology has become a convenient tool for the application of transient gene expression. This model system has allowed the study of plant responses to biotic and abiotic stresses, protein location and trafficking, cell wall dynamics, and single-cell transcriptomics, among others. Although well-established protocols for isolating protoplasts from different plant tissues are available, they have never been used for studying plant cells using cryo electron microscopy (cryo-EM) and cryo electron tomography (cryo-ET). Here we describe a workflow to prepare root protoplasts from Arabidopsis thaliana plants for cryo-ET. The process includes protoplast isolation and vitrification on EM grids, and cryo-focused ion beam milling (cryo-FIB), with the aim of tilt series acquisition. The whole workflow, from growing the plants to the acquisition of the tilt series, may take a few months. Our protocol provides a novel application to use plant protoplasts as a tool for cryo-ET.

18.
J Exp Bot ; 63(2): 785-95, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22048038

RESUMO

A 1149 bp genomic fragment corresponding to the 5' non-coding region of the PgD1 (Picea glauca Defensin 1) gene was cloned, characterized, and compared with all Arabidopsis thaliana defensin promoters. The cloned fragment was found to contain several motifs specific to defence or hormonal response, including a motif involved in the methyl jasmonate reponse, a fungal elicitor responsive element, and TC-rich repeat cis-acting element involved in defence and stress responsiveness. A functional analysis of the PgD1 promoter was performed using the uidA (GUS) reporter system in stably transformed Arabidopsis and white spruce plants. The PgD1 promoter was responsive to jasmonic acid (JA), to infection by fungus and to wounding. In transgenic spruce embryos, GUS staining was clearly restricted to the shoot apical meristem. In Arabidopsis, faint GUS coloration was observed in leaves and flowers and a strong blue colour was observed in guard cells and trichomes. Transgenic Arabidopsis plants expressing the PgD1::GUS construct were also infiltrated with the hemibiotrophic pathogen Pseudomonas syringae pv. tomato DC3000. It caused a suppression of defensin expression probably resulting from the antagonistic relationship between the pathogen-stimulated salicylic acid pathway and the jasmonic acid pathway. It is therefore concluded that the PgD1 promoter fragment cloned appears to contain most if not all the elements for proper PgD1 expression and that these elements are also recognized in Arabidopsis despite the phylogenetic and evolutionary differences that separates them.


Assuntos
Arabidopsis/genética , Defensinas/genética , Picea/genética , Regiões Promotoras Genéticas/genética , Arabidopsis/citologia , Arabidopsis/fisiologia , Cycadopsida/citologia , Cycadopsida/genética , Cycadopsida/fisiologia , Ciclopentanos/metabolismo , DNA de Plantas/genética , Defensinas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Genes Reporter , Magnoliopsida/citologia , Magnoliopsida/genética , Magnoliopsida/fisiologia , Motivos de Nucleotídeos , Oxilipinas/metabolismo , Filogenia , Picea/citologia , Picea/fisiologia , Imunidade Vegetal , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/citologia , Brotos de Planta/genética , Brotos de Planta/fisiologia , Plantas Geneticamente Modificadas , Pseudomonas syringae/fisiologia , Ácido Salicílico/metabolismo , Transdução de Sinais/fisiologia , Supressão Genética/genética
19.
New Phytol ; 189(3): 678-687, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21087262

RESUMO

The perennial plant model species Populus trichocarpa has received considerable attention in the last 5 yr because of its potential use as a bioenergy crop. The completion of its genome sequence revealed extensive homologies with the herbaceous annual species Arabidopsis thaliana. This review highlights the similarities and differences at the qualitative defence response components level, notably in putative NBS-LRR protein content and downstream defence regulators. With almost a twofold NBS-LRR gene complement compared with A. thaliana, P. trichocarpa also encodes some putative R-proteins with unusual architectures and possible DNA-binding capacity. P. trichocarpa also possesses all the known main components characteristic of TIR-NB-LRR and CC-NB-LRR signalling. However, very little has been done with regard to the components involved in the poplar qualitative response to pathogens. In addition, the relationship between plant-biotroph perception/signalling and the role of salicylic acid, an important defence compound, remains uncertain. This review aims to identify the genomic components present in poplar that could potentially participate in the qualitative response and highlights where efforts should be devoted to obtain a better understanding of the poplar qualitative defence response.


Assuntos
Genes de Plantas/imunologia , Genoma de Planta/imunologia , Doenças das Plantas/genética , Imunidade Vegetal/genética , Proteínas de Plantas/imunologia , Populus/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Populus/imunologia , Ácido Salicílico/imunologia , Transdução de Sinais/fisiologia
20.
Microorganisms ; 9(5)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34063040

RESUMO

Rust fungi cause epidemics that threaten the production of important plant species, such as wheat and soy. Melampsora larici-populina (Mlp) causes the poplar rust and encodes at least 1184 candidate effectors (CEs) whose functions are poorly known. In this study, we sequenced the transcriptome and used mass spectrometry to analyze the metabolome of Arabidopsis plants constitutively expressing 14 Mlp CEs and of a control line to discover alterations leading to plant susceptibility. We found 2299 deregulated genes across the experiment. Genes involved in pattern-triggered immunity, such as FRK1, PR1, RBOHD, and WRKY33, as well as AUX/IAA genes were down-regulated. We further observed that 680 metabolites were deregulated in at least one CE-expressing transgenic line, with "highly unsaturated and phenolic compounds" and "peptides" enriched among down- and up-regulated metabolites. Interestingly, transgenic lines expressing unrelated CEs had correlated patterns of gene and metabolite deregulation, while expression of CEs belonging to the same family deregulated different genes and metabolites. Thus, our results uncouple effector sequence similarity and function. This supports that effector functional investigation in the context of their virulence activity and effect on plant susceptibility requires the investigation of the individual effector and precludes generalization based on sequence similarity.

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