A Novel Target (Oxidation Resistant 2) in Arabidopsis thaliana to Reduce Clubroot Disease Symptoms via the Salicylic Acid Pathway without Growth Penalties

The clubroot disease (Plasmodiophora brassicae) is one of the most damaging diseases worldwide among brassica crops. Its control often relies on resistant cultivars, since the manipulation of the disease hormones, such as salicylic acid (SA) alters plant growth negatively. Alternatively, the SA pathway can be increased by the addition of beneficial microorganisms for biocontrol. However, this potential has not been exhaustively used. In this study, a recently characterized protein Oxidation Resistant 2 (OXR2) from Arabidopsis thaliana is shown to increase the constitutive pathway of SA defense without decreasing plant growth. Plants overexpressing AtOXR2 (OXR2-OE) show strongly reduced clubroot symptoms with improved plant growth performance, in comparison to wild type plants during the course of infection. Consequently, oxr2 mutants are more susceptible to clubroot disease. P. brassicae itself was reduced in these galls as determined by quantitative real-time PCR. Furthermore, we provide evidence for the transcriptional downregulation of the gene encoding a SA-methyltransferase from the pathogen in OXR2-OE plants that could contribute to the phenotype.Fil: Mencia, Regina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Welchen, Elina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Auer, Susann. Technische Universität Dresden; AlemaniaFil: Ludwig Müller, Jutta. Technische Universität Dresden; Alemani

Polymorphic inverted repeats near coding genes impact chromatin topology and phenotypic traits in Arabidopsis thaliana

Transposons are mobile elements that are commonly silenced to protect eukaryotic genome integrity. In plants, transposable element (TE)-derived inverted repeats (IRs) are commonly found near genes, where they affect host gene expression. However, the molecular mechanisms of such regulation are unclear in most cases. Expression of these IRs is associated with production of 24-nt small RNAs, methylation of the IRs, and drastic changes in local 3D chromatin organization. Notably, many of these IRs differ between Arabidopsis thaliana accessions, causing variation in short-range chromatin interactions and gene expression. CRISPR-Cas9-mediated disruption of two IRs leads to a switch in genome topology and gene expression with phenotypic consequences. Our data show that insertion of an IR near a gene provides an anchor point for chromatin interactions that profoundly impact the activity of neighboring loci. This turns IRs into powerful evolutionary agents that can contribute to rapid adaptation

Estudio de la nueva familia de proteínas OXR en plantas

Fil: Mencia, Regina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina.Fil: Mencia, Regina. Technische Universität Dresden .Bereich Mathematik und Naturwissenschaften; Alemania.OXR2 es una proteína mitocondrial de Arabidopsis que pertenece a la familia de proteínas eucariotas OXR (oxidation resistance) recientemente identificadas. La característica principal de esta familia es la presencia de un dominio TLDc en la mitad C-terminal. Para estudiar la función de la proteína OXR2, analizamos líneas mutantes de Arabipdopsis thaliana con niveles alterados de la proteína. Estas plantas exhiben características fenotípicas interesantes, particularmente las plantas que sobreexpresan la proteína bajo la acción de un promotor 35M CaMV tienen un tamaño más grande, mayor biomasa y una etapa vegetativa prolongada. Además, enfrentamos las plantas a dos patógenos diferentes: Pseudomonas syringae y Plasmodiophora brassicae, este último es el responsable de la enfermedad de la hernia de la col de importancia económica mundial. Curiosamente, las líneas sobreexpresoras presentan una mayor resistencia a ambos patógenos en comparación con las plantas de tipo salvaje (WT) y, por el contrario, una línea de T-DNA muestra ser más sensible a los mismos patógenos. Además, las plantas exhiben un contenido alterado de hormonas como las citokininas (CK) y el ácido salicílico (SA). Concluimos que nuestra proteína de interés constituye otro ejemplo con respecto a la interacción entre las actividades mitocondriales, el control hormonal del crecimiento y las defensas en las plantas.OXR2 is an Arabidopsis mitochondrial protein that belongs to the newly identified eukaryotic protein family OXR (OXidation Resistance). The main characteristic of this family is the presence of a TLDc domain at the C-terminal half. In order to study the function of the OXR2 protein we analyze Arabipdopsis thaliana mutant lines with altered levels of the protein. These plants exhibit interesting phenotypic characteristics, particularly plants that over express the protein under the action of a 35S CaMV promoter have a larger size, higher biomass and prolonged vegetative stage. Also, we face the plants to two different pathogens: Pseudomonas syringae and Plasmodiophora brassicae, this last one is the responsible for the clubroot disease of economic importance worldwide. Interestingly the over expressor lines present increased resistance to both pathogens compared to wild type (WT) plants and on the contrary a knockout T-DNA line show to be more sensible to the same pathogens. Furthermore the plants exhibit altered content of hormones like Citokinins (CK) and Salicylic acid (SA).We conclude that our protein of interest constitute another example regarding to the interplay between mitochondrial activities, hormonal control of growth and defenses in plants.Consejo Nacional de Investigaciones Científicas y TécnicasCentro Universitario Argentino-AlemánServicio Alemán de Intercambio Académic

A Novel Target (Oxidation Resistant 2) in Arabidopsis thaliana to Reduce Clubroot Disease Symptoms via the Salicylic Acid Pathway without Growth Penalties

The clubroot disease (Plasmodiophora brassicae) is one of the most damaging diseases worldwide among brassica crops. Its control often relies on resistant cultivars, since the manipulation of the disease hormones, such as salicylic acid (SA) alters plant growth negatively. Alternatively, the SA pathway can be increased by the addition of beneficial microorganisms for biocontrol. However, this potential has not been exhaustively used. In this study, a recently characterized protein Oxidation Resistant 2 (OXR2) from Arabidopsis thaliana is shown to increase the constitutive pathway of SA defense without decreasing plant growth. Plants overexpressing AtOXR2 (OXR2-OE) show strongly reduced clubroot symptoms with improved plant growth performance, in comparison to wild type plants during the course of infection. Consequently, oxr2 mutants are more susceptible to clubroot disease. P. brassicae itself was reduced in these galls as determined by quantitative real-time PCR. Furthermore, we provide evidence for the transcriptional downregulation of the gene encoding a SA-methyltransferase from the pathogen in OXR2-OE plants that could contribute to the phenotype

Keeping up with the miRNAs: current paradigms of the biogenesis pathway

For many years we have studied the processes involved in producing miRNAs in plants and the numerous differences from their metazoan counterpart. A well-defined catalytic process, mostly carried out by the RNase III enzyme DICER-LIKE1 (DCL1), it was identified early after the discovery of RNAi and was followed by the isolation of a plethora of miRNA biogenesis cofactors. The production of miRNAs, which later are loaded in ARGONAUTE (AGO) proteins to perform their RNA silencing functions both within the cell and non-cell autonomously, appears to be a highly regulated and dynamic process. Many regulatory events during miRNA biogenesis require the action of specific proteins. However, in recent years, many post-transcriptional modifications, structural features, and coupling with other cellular processing emerged as critical elements controlling the production of miRNA and, thus, a plant’s physiology. This review discusses new evidence that has changed the way we understand how miRNAs are produced in plants. We also provide an updated view of the miRNA biogenesis pathways, focusing on the gaps in our knowledge and the most compelling questions that remain open.Fil: Mencia, Regina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Gonzalo, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Tossolini, Ileana del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentin

OXR2 increases plant defense against a hemibiotrophic pathogen via the salicylic acid pathway

Arabidopsis thaliana OXIDATION RESISTANCE 2 (AtOXR2) is a mitochondrial proteinbelonging to the Oxidation Resistance (OXR) protein family, recently described in plants. Weanalyzed the impact of AtOXR2 in Arabidopsis defense mechanisms against thehemibiotrophic bacterial pathogen Pseudomonas syringae. oxr2 mutant plants are moresusceptible to infection by the pathogen and, conversely, plants over-expressing AtOXR2(oeOXR2 plants) show enhanced disease resistance. Resistance in these plants is accompaniedby higher expression of WRKY transcription factors, induction of genes involved in salicylicacid (SA) synthesis, accumulation of free SA, and overall activation of the SA-signalingpathway. Accordingly, defense phenotypes are dependent on SA-synthesis and SA-perceptionpathways, since they are lost in ics1/sid2 (isochorismate synthase 1/salicylic acid inductiondeficient 2) and npr1 (nonexpressor of pathogenesis-related genes 1) mutant backgrounds.Over-expression of AtOXR2 leads to faster and stronger oxidative burst in response to thebacterial flagellin peptide flg22. Moreover, AtOXR2 affects the nuclear localization of thetranscriptional coactivator NPR1, a master regulator of SA signaling. oeOXR2 plants haveincreased levels of total glutathione and a more oxidized cytosolic redox cellular environmentunder normal growth conditions. Therefore, AtOXR2 contributes to establishing plantprotection against infection by P. syringae acting on the activity of the SA pathway.Fil: Mencia, Regina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Céccoli, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias. Cátedra de Morfología Vegetal; ArgentinaFil: Fabro, Georgina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Torti, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Colombatti, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Ludwig-Müller, Jutta. Technische Universität Dresden; AlemaniaFil: Alvarez, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Welchen, Elina. Technische Universität Dresden; Alemani

Polymorphic inverted repeats near coding genes impact chromatin topology and phenotypic traits in Arabidopsis thaliana

Transposons are mobile elements that are commonly silenced to protect eukaryotic genome integrity. In plants, transposable element (TE)-derived inverted repeats (IRs) are commonly found near genes, where they affect host gene expression. However, the molecular mechanisms of such regulation are unclear in most cases. Expression of these IRs is associated with production of 24-nt small RNAs, methylation of the IRs, and drastic changes in local 3D chromatin organization. Notably, many of these IRs differ between Arabidopsis thaliana accessions, causing variation in short-range chromatin interactions and gene expression. CRISPR-Cas9-mediated disruption of two IRs leads to a switch in genome topology and gene expression with phenotypic consequences. Our data show that insertion of an IR near a gene provides an anchor point for chromatin interactions that profoundly impact the activity of neighboring loci. This turns IRs into powerful evolutionary agents that can contribute to rapid adaptation.Fil: Arce, Agustín Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Mencia, Regina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Cambiagno, Damián Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Estudios Agropecuarios - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Estudios Agropecuarios; ArgentinaFil: Lang, Patricia L.. University of Stanford; Estados UnidosFil: Liu, Chang. Universidad de Hohenheim; AlemaniaFil: Burbano, Hernán A.. Colegio Universitario de Londres; Reino UnidoFil: Weigel, Detlef. Max Planck Institute for Biology Tubingen; AlemaniaFil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentin

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The sunflower TLDc-containing protein HaOXR2 confers tolerance to oxidative stress and waterlogging when expressed in maize plants

The sunflower (Helianthus annuus L.) genome encodes six proteins containing a TLDc domain, typical of the eukaryotic OXidation Resistance (OXR) protein family. Expression of sunflower HaOXR2 in Arabidopsis generated plants with increased rosette diameter, higher number of leaves and increased seed production. Maize inbred lines expressing HaOXR2 also showed increased total leaf area per plant. In addition, heterologous expression of HaOXR2 induced an increase in the oxidative stress tolerance in Arabidopsis and maize. Maize transgenic plants expressing HaOXR2 experienced less oxidative damage and exhibited increased photosynthetic performance and efficiency than non-transgenic segregant plants after treatment of leaves with the reactive oxygen species generating compound Paraquat. Expression of HaOXR2 in maize also improved tolerance to waterlogging. The number of expanded leaves, aerial biomass, and stem height and cross-section area were less affected by waterlogging in HaOXR2 expressing plants, which also displayed less aerial tissue damage under these conditions. Transgenic plants also showed an increased production of roots, a typical adaptive stress response. The results show the existence of functional conservation of OXR proteins in dicot and monocot plants and indicate that HaOXR2 could be useful to improve plant performance under conditions that increase oxidative stress.Fil: Torti, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Raineri, Jesica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Mencia, Regina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Campi, Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Gonzalez, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Welchen, Elina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentin