Molecular mechanisms involved in functional macroevolution of plant transcription factors

Transcription factors (TFs) are key components of the transcriptional regulation machinery. In plants, they accompanied the evolution from unicellular aquatic algae to complex flowering plants that dominate the land environment. The adaptations of the body plan and physiological responses required changes in the biological functions of TFs. Some ancestral gene regulatory networks are highly conserved, while others evolved more recently and only exist in particular lineages. The recent emergence of novel model organisms provided the opportunity for comparative studies, producing new insights to infer these evolutionary trajectories. In this review, we comprehensively revisit the recent literature on TFs of nonseed plants and algae, focusing on the molecular mechanisms driving their functional evolution. We discuss the particular contribution of changes in DNA-binding specificity, protein–protein interactions and cis-regulatory elements to gene regulatory networks. Current advances have shown that these evolutionary processes were shaped by changes in TF expression pattern, not through great innovation in TF protein sequences. We propose that the role of TFs associated with environmental and developmental regulation was unevenly conserved during land plant evolution.Fil: Romani, Facundo Alihuen. 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: Moreno, Javier Edgardo. 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

Laboratórios de agrobiotecnologia: níveis de decisão em trajetórias de transferência de tecnologia

Historically the production of scientific knowledge in Argentina is characterized by a large gap between industry and scientific research. However, in recent years it can be seen premature cases of innovation which articulate relationships between researchers and companies. It is particulary interesting the study of agribiotechnology.The present work is carried out in the context of social studies of science and technology and it aims to analyze the trajectories of research and development laboratories cases which have projects in technology transfer to companies. The purpose is to characterize the strategies developed to guide their research in this direction.The general findings illustrate the existence of different levels of decision making that are key in achieving technology transfer. These decisions shape strategies which manage to coexist laboratory research and transfer.Históricamente la producción de conocimiento científico en Argentina se caracteriza por una gran separación entre el sector productivo y la investigación científica. Sin embargo, en los últimos años se puede observar incipientes casos de innovación que articulan relaciones entre los investigadores y empresas. Particularmente interesa estudiar el caso de la agrobiotecnología.Este trabajo se realiza en el marco de los estudios sociales de la ciencia y la tecnología y busca analizar las trayectorias de casos de laboratorios de investigación y desarrollo que tienen proyectos de transferencia tecnológica hacia empresas. El objetivo consiste en caracterizar las estrategias que desarrollan para orientar sus investigaciones en ese sentido.Las conclusiones generales ilustran la existencia de distintos niveles de decisión que resultan claves en la realización de la transferencia tecnológica. Esas decisiones conforman estrategias donde los laboratorios logran hacer coexistir actividades de investigación y transferencia.Historicamente a produção de conhecimento científico na Argentina é caracterizada por uma grande separação entre o setor produtivo e a investigação científica. No entanto, nos últimos anos podem se observar casos incipientes de inovação que articulam relações entre os investigadores e empresas. Particularmente interessa estudar o caso da agrobiotecnologia. Este trabalho é realizado no âmbito dos estudos sociais da ciência e a tecnologia e busca analisar as trajetórias de casos de laboratórios de pesquisa e desenvolvimento que têm projetos de transferência de tecnologia para empresas. O objetivo é caracterizar as estratégias desenvolvidas para orientar suas investigações nesse sentido. As conclusões gerais ilustram a existência de diferentes níveis de decisão que resultam fundamentais na realização da transferência de tecnologia. Essas decisões conformam estratégias onde os laboratórios conseguem fazer coexistir atividades de investigação e transferência

The Polycomb repressive complex 2 deposits H3K27me3 and represses transposable elements in a broad range of eukaryotes

The mobility of transposable elements (TEs) contributes to evolution of genomes. Their uncontrolled activity causes genomic instability; therefore, expression of TEs is silenced by host genomes. TEs are marked with DNA and H3K9 methylation, which are associated with silencing in flowering plants, animals, and fungi. However, in distantly related groups of eukaryotes, TEs are marked by H3K27me3 deposited by the Polycomb repressive complex 2 (PRC2), an epigenetic mark associated with gene silencing in flowering plants and animals. The direct silencing of TEs by PRC2 has so far only been shown in one species of ciliates. To test if PRC2 silences TEs in a broader range of eukaryotes, we generated mutants with reduced PRC2 activity and analyzed the role of PRC2 in extant species along the lineage of Archaeplastida and in the diatom P. tricornutum. In this diatom and the red alga C. merolae, a greater proportion of TEs than genes were repressed by PRC2, whereas a greater proportion of genes than TEs were repressed by PRC2 in bryophytes. In flowering plants, TEs contained potential cis-elements recognized by transcription factors and associated with neighbor genes as transcriptional units repressed by PRC2. Thus, silencing of TEs by PRC2 is observed not only in Archaeplastida but also in diatoms and ciliates, suggesting that PRC2 deposited H3K27me3 to silence TEs in the last common ancestor of eukaryotes. We hypothesize that during the evolution of Archaeplastida, TE fragments marked with H3K27me3 were selected to shape transcriptional regulation, controlling networks of genes regulated by PRC2

The Intrinsically Disordered Protein CARP9 Bridges HYL1 to AGO1 in the Nucleus to Promote MicroRNA Activity

In plants, small RNAs (sRNA) are loaded into ARGONAUTE (AGO) proteins to fulfill their regulatory functions. Micro RNAs (miRNAs), one of the most abundant classes of endogenous sRNAs, are preferentially loaded into ARGONAUTE1 (AGO1). Such loading, long believed to happen exclusively in the cytoplasm, was recently proposed to also occur in the nucleus. Here we identified CONSTITUTIVE ALTERATIONS IN THE SMALL RNAS PATHWAYS9 (CARP9), a nuclear-localized, intrinsically disordered protein, as a factor promoting miRNA activity in Arabidopsis (Arabidopsis thaliana). Mutations in the CARP9-encoding gene led to a mild reduction of miRNAs levels, impaired gene silencing, and characteristic morphological defects, including young leaf serration and altered flowering time. Intriguingly, we found that CARP9 was able to interact with HYPONASTIC LEAVES1 (HYL1), but not with other proteins of the miRNA biogenesis machinery. In the same way, CARP9 appeared to interact with mature miRNA, but not with pri-miRNA, positioning it after miRNA processing in the miRNA pathway. CARP9 was also able to interact with AGO1, promoting its interaction with HYL1 to facilitate miRNA loading in AGO1. Plants deficient in CARP9 displayed reduced levels of AGO1-loaded miRNAs, partial retention of miRNA in the nucleus, and reduced levels of AGO1. Collectively, our data suggest that CARP9 might modulate HYL1AGO1 crosstalk, acting as a scaffold for the formation of a nuclear post pri-miRNA processing complex that includes at least HYL1, AGO1 and HSP90. In such a complex, CARP9 stabilizes AGO1 and mature miRNAs, allowing the proper loading of miRNAs in the effector complex.Fil: Tomassi, Ariel Hernán. 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: Ré, Delfina Adela. 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: Romani, Facundo Alihuen. 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; 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: Moreno, Javier Edgardo. 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: 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: 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

ROS-Scavenging Enzymes as an Antioxidant Response to High Concentration of Anthracene in the Liverwort <i>Marchantia polymorpha</i> L.

Marchantia polymorpha L. responds to environmental changes using a myriad set of physiological responses, some unique to the lineage related to the lack of a vascular- and root-system. This study investigates the physiological response of M. polymorpha to high doses of anthracene analysing the antioxidant enzymes and their relationship with the photosynthetic processes, as well as their transcriptomic response. We found an anthracene dose-dependent response reducing plant biomass and associated to an alteration of the ultrastructure of a 23.6% of chloroplasts. Despite a reduction in total thallus-chlorophyll of 31.6% of Chl a and 38.4% of Chl b, this was not accompanied by a significant change in the net photosynthesis rate and maximum quantum efficiency (Fv/Fm). However, we found an increase in the activity of main ROS-detoxifying enzymes of 34.09% of peroxidase and 692% of ascorbate peroxidase, supported at transcriptional level with the upregulation of ROS-related detoxifying responses. Finally, we found that M. polymorpha tolerated anthracene-stress under the lowest concentration used and can suffer physiological alterations under higher concentrations tested related to the accumulation of anthracene within plant tissues. Our results show that M. polymorpha under PAH stress condition activated two complementary physiological responses including the activation of antioxidant mechanisms and the accumulation of the pollutant within plant tissues to mitigate the damage to the photosynthetic apparatus

The Polycomb repressive complex 2 deposits H3K27me3 and represses transposable elements in a broad range of eukaryotes

The mobility of transposable elements (TEs) contributes to evolution of genomes. Their uncontrolled activity causes genomic instability; therefore, expression of TEs is silenced by host genomes. TEs are marked with DNA and H3K9 methylation, which are associated with silencing in flowering plants, animals, and fungi. However, in distantly related groups of eukaryotes, TEs are marked by H3K27me3 deposited by the Polycomb repressive complex 2 (PRC2), an epigenetic mark associated with gene silencing in flowering plants and animals. The direct silencing of TEs by PRC2 has so far only been shown in one species of ciliates. To test if PRC2 silences TEs in a broader range of eukaryotes, we generated mutants with reduced PRC2 activity and analyzed the role of PRC2 in extant species along the lineage of Archaeplastida and in the diatom P. tricornutum. In this diatom and the red alga C. merolae, a greater proportion of TEs than genes were repressed by PRC2, whereas a greater proportion of genes than TEs were repressed by PRC2 in bryophytes. In flowering plants, TEs contained potential cis-elements recognized by transcription factors and associated with neighbor genes as transcriptional units repressed by PRC2. Thus, silencing of TEs by PRC2 is observed not only in Archaeplastida but also in diatoms and ciliates, suggesting that PRC2 deposited H3K27me3 to silence TEs in the last common ancestor of eukaryotes. We hypothesize that during the evolution of Archaeplastida, TE fragments marked with H3K27me3 were selected to shape transcriptional regulation, controlling networks of genes regulated by PRC2

Origin of TAA genes in charophytes: New insights into the controversy over the origin of auxin biosynthesis

There is a current controversy around the origin of auxin biosynthesis genes in plants. Auxin is one of the most important plant hormone and its major biosynthesis pathway implies the tryptophan aminotransferase (TAA) and flavin containing monooxygenases (YUCCA) gene families (Mashiguchi et al., 2011). The hormone is present in all land plants and also in charophycean algae. Recently, it was demonstrated that algae also respond to auxin (Stirk et al., 2013; Ohtaka et al., 2017), but the presence of the biosynthesis genes in this lineage is still not clear.Fil: Romani, Facundo Alihuen. 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

Respuesta del rendimiento en cultivares de trigo a la aplicación de fungicida para el control de roya anaranjada (puccinia triticina) en el área de riego del río Dulce de Santiago del Estero

Una de las causas principales de la perdida e inestabilidad en los rendimientos en trigo son las enfermedades. Dentro de las enfermedades que se destacan por su incidencia sobre el rendimiento, se encuentra la roya anaranjada o de la hoja (Puccinia triticina). Esta enfermedad puede llegar a producir pérdidas de rendimiento de hasta el 55%. La utilización de cultivares con resistencia genética es la principal estrategia de manejo cultural para el control de enfermedades. Sin embargo, en cultivares susceptibles a la roya anaranjada, el control químico puede ser muy eficaz. El objetivo de este trabajo fue estudiar el efecto de la roya anaranjada, sobre el rendimiento en grano en diferentes cultivares de trigo en el área de riego del Río Dulce de Santiago del Estero.EEA Santiago del EsteroFil: Valentini, Facundo. Consultor privado; ArgentinaFil: Romani, Matías Rafael. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santiago del Estero; ArgentinaFil: Romani, Matías Rafael. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias. Cátedra de Sistemas Productivos de Cereales y Forrajes; Argentin

Laboratorios de agrobiotecnología: niveles de decisión en trayectorias de transferencia tecnológica

Históricamente la producción de conocimiento científico en Argentina se caracteriza por una gran separación entre el sector productivo y la investigación científica. Sin embargo, en los últimos años se puede observar incipientes casos de innovación que articulan relaciones entre los investigadores y empresas. Particularmente interesa estudiar el caso de la agrobiotecnología.Este trabajo se realiza en el marco de los estudios sociales de la ciencia y la tecnología y busca analizar las trayectorias de casos de laboratorios de investigación y desarrollo que tienen proyectos de transferencia tecnológica hacia empresas. El objetivo consiste en caracterizar las estrategias que desarrollan para orientar sus investigaciones en ese sentido.Las conclusiones generales ilustran la existencia de distintos niveles de decisión que resultan claves en la realización de la transferencia tecnológica. Esas decisiones conforman estrategias donde los laboratorios logran hacer coexistir actividades de investigación y transferencia.Historically the production of scientific knowledge in Argentina is characterized by a large gap between industry and scientific research. However, in recent years it can be seen premature cases of innovation which articulate relationships between researchers and companies. It is particulary interesting the study of agribiotechnology.The present work is carried out in the context of social studies of science and technology and it aims to analyze the trajectories of research and development laboratories cases which have projects in technology transfer to companies. The purpose is to characterize the strategies developed to guide their research in this direction.The general findings illustrate the existence of different levels of decision making that are key in achieving technology transfer. These decisions shape strategies which manage to coexist laboratory research and transfer.Historicamente a produção de conhecimento científico na Argentina é caracterizada por uma grande separação entre o setor produtivo e a investigação científica. No entanto, nos últimos anos podem se observar casos incipientes de inovação que articulam relações entre os investigadores e empresas. Particularmente interessa estudar o caso da agrobiotecnologia. Este trabalho é realizado no âmbito dos estudos sociais da ciência e a tecnologia e busca analisar as trajetórias de casos de laboratórios de pesquisa e desenvolvimento que têm projetos de transferência de tecnologia para empresas. O objetivo é caracterizar as estratégias desenvolvidas para orientar suas investigações nesse sentido. As conclusões gerais ilustram a existência de diferentes níveis de decisão que resultam fundamentais na realização da transferência de tecnologia. Essas decisões conformam estratégias onde os laboratórios conseguem fazer coexistir atividades de investigação e transferência