Rhizopine biosensors for plant-dependent control of bacterial gene expression

Engineering signalling between plants and microbes could be exploited to establish host-specificity between plant-growth-promoting bacteria and target crops in the environment. We previously engineered rhizopine-signalling circuitry facilitating exclusive signalling between rhizopine-producing (RhiP) plants and model bacterial strains. Here, we conduct an in-depth analysis of rhizopine-inducible expression in bacteria. We characterize two rhizopine-inducible promoters and explore the bacterial host-range of rhizopine biosensor plasmids. By tuning the expression of rhizopine uptake genes, we also construct a new biosensor plasmid pSIR05 that has minimal impact on host cell growth in vitro and exhibits markedly improved stability of expression in situ on RhiP barley roots compared to the previously described biosensor plasmid pSIR02. We demonstrate that a sub-population of Azorhizobium caulinodans cells carrying pSIR05 can sense rhizopine and activate gene expression when colonizing RhiP barley roots. However, these bacteria were mildly defective for colonization of RhiP barley roots compared to the wild-type parent strain. This work provides advancement towards establishing more robust plant-dependent control of bacterial gene expression and highlights the key challenges remaining to achieve this goal

PhDAY 2020 -FOO (Facultad de Óptica y Optometría)

Por cuarto año consecutivo los doctorandos de la Facultad de Óptica y Optometría de la Universidad Complutense de Madrid cuentan con un congreso propio organizado por y para ellos, el 4º PhDAY- FOO. Se trata de un congreso gratuito abierto en la que estos jóvenes científicos podrán presentar sus investigaciones al resto de sus compañeros predoctorales y a toda la comunidad universitaria que quiera disfrutar de este evento. Apunta en tu agenda: el 15 de octubre de 2020. En esta ocasión será un Congreso On-line para evitar que la incertidumbre asociada a la pandemia Covid-19 pudiera condicionar su celebración

Opportunities and challenges in the professional development of teachers with ICT in a rural school in Spain: a look at the New School

Partiendo de una mirada retrospectiva hacia la Escuela Nueva, se busca en este trabajo reflexionar acerca de las oportunidades y desafíos que las TIC plantean para el desarrollo profesional docente. Inicialmente, proporcionaremos algunos de los principales hitos históricos y repercusiones de la ILE y la Escuela Nueva en nuestro país. Posteriormente, abordaremos una experiencia de formación de profesorado en el marco de un estudio de caso llevado a cabo durante tres años en una escuela rural con el objetivo de proporcionar algunas evidencias acerca de cómo promover la creación y compartición de diseños educativos innovadores en el uso de las TIC a través de una plataforma tecnológica consensuada y compartida por una comunidad de aprendizaje. En la última sección presentaremos algunas de las principales evidencias obtenidas tratando de establecer paralelismos con las repercusiones que la Escuela Nueva tiene para el desarrollo de competencias profesionales docentes en pleno siglo xxi.The based on a retrospective look at the New School, this article attempts to reflect on the opportunities and challenges posed by ICTs for teachers’ professional development. First, we will present some of the major historical milestones and effects of the Free Teaching Institution (ILE) and the New School in Spain. Then we will address a teacher training experience in the context of a case study conducted over 3 years in a rural school in order to provide some evidence on how to promote the creation and sharing of innovative educational designs using ICT through an agreed and shared technology platform for a learning community. In the last section, we will provide key evidence obtained by trying to draw similarities with the consequences that the New School has for the development of teaching skills in the 21st century

Oportunidades y desafíos en el desarrollo profesional de docentes con TIC en una escuela rural en España: una mirada a la Escuela Nueva

Partiendo de una mirada retrospectiva hacia la Escuela Nueva, se busca en este trabajo reflexionar acerca de las oportunidades y desafíos que las TIC plantean para el desarrollo profesional docente. Inicialmente, proporcionaremos algunos de los principales hitos históricos y repercusiones de la ILE y la Escuela Nueva en nuestro país. Posteriormente, abordaremos una experiencia de formación de profesorado en el marco de un estudio de caso llevado a cabo durante 3 años en una escuela rural con el objetivo de proporcionar algunas evidencias acerca de cómo promover la creación y compartición de diseños educativos innovadores en el uso de las TIC a través de una plataforma tecnológica consensuada y compartida por una comunidad de aprendizaje. En la última sección presentaremos algunas de las principales evidencias obtenidas tratando de establecer paralelismos con las repercusiones que la Escuela Nueva tiene para el desarrollo de competencias profesionales docentes en pleno siglo XXIBased on a retrospective look at the New School, this article attempts to reflect on the opportunities and challenges posed by ICTs for teachers� professional development. First, we will present some of the major historical milestones and effects of the Free Teaching Institution (ILE) and the New School in Spain. Then we will address a teacher training experience in the context of a case study conducted over 3 years in a rural school in order to provide some evidence on how to promote the creation and sharing of innovative educational designs using ICT through an agreed and shared technology platform for a learning community. In the last section, we will provide key evidence obtained by trying to draw similarities with the consequences that the New School has for the development of teaching skills in the 21st centur

Rhizopine biosensors for plant-dependent control of bacterial gene expression.

Engineering signalling between plants and microbes could be exploited to establish host-specificity between plant-growth-promoting bacteria and target crops in the environment. We previously engineered rhizopine-signalling circuitry facilitating exclusive signalling between rhizopine-producing (RhiP) plants and model bacterial strains. Here, we conduct an in-depth analysis of rhizopine-inducible expression in bacteria. We characterize two rhizopine-inducible promoters and explore the bacterial host-range of rhizopine biosensor plasmids. By tuning the expression of rhizopine uptake genes, we also construct a new biosensor plasmid pSIR05 that has minimal impact on host cell growth in vitro and exhibits markedly improved stability of expression in situ on RhiP barley roots compared to the previously described biosensor plasmid pSIR02. We demonstrate that a sub-population of Azorhizobium caulinodans cells carrying pSIR05 can sense rhizopine and activate gene expression when colonizing RhiP barley roots. However, these bacteria were mildly defective for colonization of RhiP barley roots compared to the wild-type parent strain. This work provides advancement towards establishing more robust plant-dependent control of bacterial gene expression and highlights the key challenges remaining to achieve this goal

Genomic Diversity in the Endosymbiotic Bacterium Rhizobium leguminosarum

Rhizobium leguminosarum bv. viciae is a soil α-proteobacterium that establishes a diazotrophic symbiosis with different legumes of the Fabeae tribe. The number of genome sequences from rhizobial strains available in public databases is constantly increasing, although complete, fully annotated genome structures from rhizobial genomes are scarce. In this work, we report and analyse the complete genome of R. leguminosarum bv. viciae UPM791. Whole genome sequencing can provide new insights into the genetic features contributing to symbiotically relevant processes such as bacterial adaptation to the rhizosphere, mechanisms for efficient competition with other bacteria, and the ability to establish a complex signalling dialogue with legumes, to enter the root without triggering plant defenses, and, ultimately, to fix nitrogen within the host. Comparison of the complete genome sequences of two strains of R. leguminosarum bv. viciae, 3841 and UPM791, highlights the existence of different symbiotic plasmids and a common core chromosome. Specific genomic traits, such as plasmid content or a distinctive regulation, define differential physiological capabilities of these endosymbionts. Among them, strain UPM791 presents unique adaptations for recycling the hydrogen generated in the nitrogen fixation process.Funding for this work was provided by Spain’s MINECO (BIO2013-43040-P to José M. Palacios) and the USA’s National Institutes of Health (2R01GM080227 for the Analysis Engine to Michelle G. Giglio)