Open Access
NTRC and thioredoxin f overexpression differentially induces starch accumulation in tobacco leaves
(MDPI, 2019) Ancín Rípodas, María; Larraya Reta, Luis María; Fernández San Millán, Alicia; Veramendi Charola, Jon; Burch Smith, Tessa; Farrán Blanch, Inmaculada; Institute for Multidisciplinary Research in Applied Biology - IMAB
Thioredoxin (Trx) f and NADPH-dependent Trx reductase C (NTRC) have both been proposed as major redox regulators of starch metabolism in chloroplasts. However, little is known regarding the specific role of each protein in this complex mechanism. To shed light on this point, tobacco plants that were genetically engineered to overexpress the NTRC protein from the chloroplast genome were obtained and compared to previously generated Trx f-overexpressing transplastomic plants. Likewise, we investigated the impact of NTRC and Trx f deficiency on starch metabolism by generating Nicotiana benthamiana plants that were silenced for each gene. Our results demonstrated that NTRC overexpression induced enhanced starch accumulation in tobacco leaves, as occurred with Trx f. However, only Trx f silencing leads to a significant decrease in the leaf starch content. Quantitative analysis of enzyme activities related to starch synthesis and degradation were determined in all of the genotypes. Zymographic analyses were additionally performed to compare the amylolytic enzyme profiles of both transplastomic tobacco plants. Our findings indicated that NTRC overexpression promotes the accumulation of transitory leaf starch as a consequence of a diminished starch turnover during the dark period, which seems to be related to a significant reductive activation of ADP-glucose pyrophosphorylase and/or a deactivation of a putative debranching enzyme. On the other hand, increased starch content in Trx f-overexpressing plants was connected to an increase in the capacity of soluble starch synthases during the light period. Taken together, these results suggest that NTRC and the ferredoxin/Trx system play distinct roles in starch turnover.
Open Access
New trends in the global digital transformation process of the agri-food sector: an exploratory study based on Twitter
(Elsevier, 2022) Ancín Rípodas, María; Pindado Tapia, Emilio; Sánchez García, Mercedes; Enpresen Kudeaketa; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Gestión de Empresas
CONTEXT: The agri-food system is undergoing pervasive changes in business models, facilitated by the use of digital technologies. Although today it is almost inevitable for any business to adopt some level of digital transformation to strengthen their competitiveness, this transition in the agri-food sector could be more complex, given its characteristics. OBJECTIVE: The aim of the study is to analyse worldwide the perceptions of new digital technologies in the agri-food sector expressed within social media platforms, identifying the differences that may exist between them regarding its objectives and social acceptance. METHODS: This paper examines the information regarding digital transformation process in the agri-food sector disseminated worldwide on Twitter. For that purpose, Twitter API is used to gather tweets and descriptive and content analyses, including a sentiment analysis, are performed using R and MAXQDA software. RESULTS AND CONCLUSIONS: We found that the digitalization of the agri-food sector is broadly discussed within Twitter. Different actors participate in these information flows, being companies and digital solution providers the most active users and academics and governmental institutions the most visible. Artificial Intelligence was the most mentioned technology, that together with the Internet of Things, Big Data, Machine Learning, and Cloud Computing, was related to improving production efficiencies, crop yield, or cost reduction. In the case of Blockchain Technology, it was closer to food supply chain actors, such as distribution companies and marketers. However, all these technologies are connected to the concept of sustainability. The sentiment analysis showed a generally positive tone, indicating social acceptance regarding the starting phase of the adoption of these technologies. The study also identified differences among countries, pointing to a stronger level of engagement with these technologies in developed regions. Moreover, the COVID-19 pandemic was seen as a chance to boost the digital transformation in the sector all over the world. SIGNIFICANCE: Our results demonstrate that data harvested from Twitter provide useful insight into perceptions of digital transformation and different digital technologies in the agri-food value chain across different countries. Information that could be useful for researchers, but also for agricultural firms and policymakers.
Open Access
Overexpression of thioredoxin m in chloroplasts alters carbon and nitrogen partitioning in tobacco
(Oxford University Press, 2021) Ancín Rípodas, María; Larraya Reta, Luis María; Florez-Sarasa, Igor; Bénard, Camille; Fernández San Millán, Alicia; Veramendi Charola, Jon; Gibon, Yves; Fernie, Alisdair R.; Aranjuelo Michelena, Iker; Farrán Blanch, Inmaculada; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación
In plants, there is a complex interaction between carbon (C) and nitrogen (N) metabolism, and its coordination is fundamental for plant growth and development. Here, we studied the influence of thioredoxin (Trx) m on C and N partitioning using tobacco plants overexpressing Trx m from the chloroplast genome. The transgenic plants showed altered metabolism of C (lower leaf starch and soluble sugar accumulation) and N (with higher amounts of amino acids and soluble protein), which pointed to an activation of N metabolism at the expense of carbohydrates. To further delineate the effect of Trx m overexpression, metabolomic and enzymatic analyses were performed on these plants. These results showed an up-regulation of the glutamine synthetase-glutamate synthase pathway; specifically tobacco plants overexpressing Trx m displayed increased activity and stability of glutamine synthetase. Moreover, higher photorespiration and nitrate accumulation were observed in these plants relative to untransformed control plants, indicating that overexpression of Trx m favors the photorespiratory N cycle rather than primary nitrate assimilation. Taken together, our results reveal the importance of Trx m as a molecular mediator of N metabolism in plant chloroplasts.
Open Access
Post-harvest light treatment increases expression levels of recombinant proteins in transformed plastids of potato tubers
(Wiley, 2015) Larraya Reta, Luis María; Fernández San Millán, Alicia; Ancín Rípodas, María; Farrán Blanch, Inmaculada; Veramendi Charola, Jon; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Plastid genetic engineering represents an attractive system for the production of foreign proteins in plants. Although high expression levels can be achieved in leaf chloroplasts, the results for non-photosynthetic plastids are generally discouraging, mainly due to low transcriptional and translational rates in comparison with chloroplasts. Here, we report the expression of two thioredoxin genes (trx f and m) from the potato plastid genome to study transgene expression in amyloplasts. As expected, the highest transgene expression was detected in the leaf (up to 4.2% of TSP). The Trx protein content in the tuber was approximately 2-3 orders of magnitude lower than in the leaf. However, we demonstrate that a simple post-harvest light treatment of microtubers developed in vitro or soil-grown tubers induces up to 55 times higher accumulation of the recombinant protein in just 7-10 days. The promoter and 5’-UTR of the psbA gene displayed higher light induction than the rrn promoter. After the applied treatment, the Trx f levels in microtubers and soil-grown tubers increased to 0.14% and 0.11% of TSP, respectively. Moreover, tubers stored for 8 months maintained the capacity of increasing the foreign protein levels after the light treatment. Post-harvest cold induction (up to 5 times) at 4 ºC was also detected in microtubers. We conclude that plastid transformation and post-harvest light treatment could be an interesting approach for the production of foreign proteins in potato.
Open Access
Plant growth-promoting traits of yeasts isolated from Spanish vineyards: benefits for seedling development
(Elsevier, 2020) Fernández San Millán, Alicia; Farrán Blanch, Inmaculada; Larraya Reta, Luis María; Ancín Rípodas, María; Arregui Odériz, Luis Miguel; Veramendi Charola, Jon; Institute for Multidisciplinary Research in Applied Biology - IMAB; Gobierno de Navarra / Nafarroako Gobernua
It is known that some microorganisms can enhance plant development. However, the use of yeasts as growth-promoting agents has been poorly investigated. The aim of this study was the characterisation of a collection of 69 yeast strains isolated from Spanish vineyards. Phytobeneficial attributes such as solubilisation of nutrients, synthesis of active biomolecules and cell wall-degrading enzyme production were analysed. Strains that revealed multiple growth-promoting characteristics were identified. The in vitro co-culture of Nicotiana benthamiana with yeast isolates showed enhancement of plant growth in 10 strains (up to 5-fold higher shoot dry weight in the case of Hyphopichiapseudoburtonii Hp-54), indicating a beneficial direct yeast-plant interaction. In addition, 18 out of the 69 strains increased dry weight and the number of roots per seedling when tobacco seeds were inoculated. Two of these, Pichia dianae Pd-2 and Meyerozymaguilliermondii Mg-11, also increased the chlorophyll content. The results in tobacco were mostly reproduced in lettuce with these two strains, which demonstrates that the effect of the yeast-plant interaction is not species-specific. In addition, the yeast collection was evaluated in maize seedlings grown in soil in a phytotron. Three isolates (Debaryomyces hansenii Dh-67, Lachancea thermotolerans Lt-69 and Saccharomyces cerevisiae Sc-6) promoted seedling development (increases of 10 % in dry weight and chlorophyll content). In conclusion, our data confirm that several yeast strains can promote plant growth and could be considered for the development of biological fertiliser treatments.
Open Access
Overexpression of plastidial thioredoxin f leads to enhanced starch accumulation in tobacco leaves
(Wiley, 2013) Sanz Barrio, Ruth; Corral-Martínez, Patricia; Ancín Rípodas, María; Seguí-Simarro, José M.; Farrán Blanch, Inmaculada; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, IIM10865.RI1
Starch, the most abundant storage carbohydrate in plants, has been a major feedstock for first‐generation biofuels. Growing fuel demands require, however, that the starch yields of energy crops be improved. Leaf starch is synthesised during the day and degraded at night to power nonphotosynthetic metabolism. Redox regulation has been associated with the coordination of the enzymes involved in starch metabolism, but neither the signals nor mechanisms that regulate this metabolism are entirely clear. In this work, the thioredoxin (Trx) f and m genes, which code for key enzymes in plastid redox regulation, were overexpressed from the plastid genome. Tobacco plants overexpressing Trx f, but not Trx m, showed an increase of up to 700% in leaf starch accumulation, accompanied by an increase in leaf sugars, specific leaf weight (SLW), and leaf biomass yield. To test the potential of these plants as a nonfood energy crop, tobacco leaves overexpressing Trx f were subjected to enzymatic hydrolysis, and around a 500% increase in the release of fermentable sugars was recorded. The results show that Trx f is a more effective regulator of photosynthetic carbon metabolism in planta than Trx m. The overexpression of Trx f might therefore provide a means of increasing the carbohydrate content of plants destined for use in biofuel production. It might also provide a means of improving the nutritional properties of staple food crops.
Open Access
Functional improvement of human cardiotrophin 1 produced in tobacco chloroplasts by co-expression with plastid thioredoxin m
(MDPI, 2020) Ancín Rípodas, María; Sanz Barrio, Ruth; Santamaría, Eva; Fernández San Millán, Alicia; Larraya Reta, Luis María; Veramendi Charola, Jon; Farrán Blanch, Inmaculada; Institute for Multidisciplinary Research in Applied Biology - IMAB
Human cardiotrophin 1 (CT1), a cytokine with excellent therapeutic potential, was previously expressed in tobacco chloroplasts. However, the growth conditions required to reach the highest expression levels resulted in an impairment of its bioactivity. In the present study, we have examined new strategies to modulate the expression of this recombinant protein in chloroplasts so as to enhance its production and bioactivity. In particular, we assessed the effect of both the fusion and co-expression of Trx m with CT1 on the production of a functional CT1 by using plastid transformation. Our data revealed that the Trx m fusion strategy was useful to increase the expression levels of CT1 inside the chloroplasts, although CT1 bioactivity was significantly impaired, and this was likely due to steric hindrance between both proteins. By contrast, the expression of functional CT1 was increased when co-expressed with Trx m, because we demonstrated that recombinant CT1 was functionally active during an in vitro signaling assay. While Trx m/CT1 co-expression did not increase the amount of CT1 in young leaves, our results revealed an increase in CT1 protein stability as the leaves aged in this genotype, which also improved the recombinant protein’s overall production. This strategy might be useful to produce other functional biopharmaceuticals in chloroplasts.
Open Access
Evaluación de diferentes tipos de fertilizantes químicos y orgánicos en la producción de frijol (Phaseolus vulgaris L. var. Alubia) en el distrito de San Juan de Castrovirreyna-Huancavelica (Perú)
(2011) Ancín Rípodas, María; Arregui Odériz, Luis Miguel; Escuela Técnica Superior de Ingenieros Agrónomos; Nekazaritza Ingeniarien Goi Mailako Eskola Teknikoa; Producción Agraria; Nekazaritza Ekoizpena
El frijol o judía verde (Phaseolus vulgarisL.) es uno de los cultivos andinos que del Perú. A pesar de que el país cuenta con alimentos suficientes para su población, existe una falta de disponibilidad y acceso a ellos que hacen que uno de cada cuatro peruanos padezca hambre y malnutrición crónica. En el ámbito rural esa cifra supera el 40% (ENDES 2000). En este sentido, con el presente Trabajo Fin de Carrera se estudia la fertilización en el cultivo de frijol utilizando diferentes tipos de fertilizantes, minerales y orgánicos, para comprobar cuáles producen los mejores rendimientos y llevan un menor coste asociado. Aspecto que en definitiva, se traduce en un mayor beneficio para el agricultor. Los ensayos se han llevado a cabo en el distrito de San Juan de Castrovirreyna, región de Huancavelica. Se establecieron dos parcelas experimentales. La primera ubicada en la capital de distrito (San Juan de Castrovirreyna) en un terreno cedido por la ONGD Desco. La otra en la localidad de Quilca, en un terreno cedido por un agricultor local. Se ha ensayado con la variedad Alubia, cuya introducción en la zona ha sido reciente, pero se han obtenido buenos rendimientos en vaina verde en campañas anteriores. En general el cultivo se llevó a cabo entre los meses de agosto y noviembre. El manejo del cultivo se realizó de forma similar a lo acostumbrado en la zona. Pero se llevó a cabo un seguimiento del cultivo en cuanto a plagas, enfermedades, condiciones climáticas, etc. A partir de estas observaciones se deciden los tratamientos fitosanitarios y riegos necesarios. Al final del cultivo se realizó la cosecha para obtener el rendimiento y también se hicieron muestreos, tales como altura y peso fresco de planta, pero sobre todo los que incumben al rendimiento como peso fresco y seco de las vainas, longitud de vainas o peso de 100 granos. Finalmente, los resultados obtenidos muestran que, estadísticamente, ninguno de los tratamientos presentó un rendimiento superior al resto, aunque sí se muestra una tendencia de los fertilizantes químicos a conseguirlo, ya que en algunos parámetros de rendimiento como peso fresco y seco de vaina o longitud de vaina sí obtuvieron los mejores resultados. A nivel económico los fertilizantes químicos y el testigo (sin fertilización) dieron lugar a los mayores beneficios, pero con ventaja ligera frente a los orgánicos, exceptuando los tratamientos en los que se aplicó biol, cuyo coste fue muy elevado, lo que dio lugar a beneficios mucho menores.
Open Access
Photosynthetic metabolism under stressful growth conditions as a bases for crop breeding and yield improvement
(MDPI, 2020) Morales Iribas, Fermín; Ancín Rípodas, María; Fakhet, Dorra; González Torralba, Jon; Gámez Guzmán, Angie Lorena; Seminario Huárriz, Amaia; Soba Hidalgo, David; Ben Mariem, Sinda; Garriga, Miguel; Aranjuelo Michelena, Iker; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Agronomía, Biotecnología y Alimentación
Increased periods of water shortage and higher temperatures, together with a reduction in nutrient availability, have been proposed as major factors that negatively impact plant development. Photosynthetic CO2 assimilation is the basis of crop production for animal and human food, and for this reason, it has been selected as a primary target for crop phenotyping/breeding studies. Within this context, knowledge of the mechanisms involved in the response and acclimation of photosynthetic CO2 assimilation to multiple changing environmental conditions (including nutrients, water availability, and rising temperature) is a matter of great concern for the understanding of plant behavior under stress conditions, and for the development of new strategies and tools for enhancing plant growth in the future. The current review aims to analyze, from a multi-perspective approach (ranging across breeding, gas exchange, genomics, etc.) the impact of changing environmental conditions on the performance of the photosynthetic apparatus and, consequently, plant growth.
Open Access
Successful biocontrol of Pichia spp. strains against Botrytis cinerea infection in apple fruit: unraveling protection mechanisms from proteomic insights
(Elseiver, 2024-05-25) Fernández San Millán, Alicia; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Larraya Reta, Luis María; Ancín Rípodas, María; Farrán Blanch, Inmaculada; Veramendi Charola, Jon; Institute for Multidisciplinary Research in Applied Biology - IMAB; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Botrytis cinerea causes major crop losses, especially under postharvest conditions. We have found that Pichia fermentans Pf-31 and Pichia terricola Pt-36 are two promising yeast strains that are able to efficiently control B. cinerea infection in apples. This effect is most pronounced when the yeasts are applied as live cells, although dead cells or culture filtrates also show some degree of control. Both strains arrest spore germination, inhibit mycelial growth, strongly attach to hyphae and promote their own proliferation in the fruit when B. cinerea is present, probably due to preferential colonization of apple wounds. Indeed, this metabolism enhancement was corroborated by a proteomic analysis, which revealed the differentially accumulated yeast proteins that contribute towards this antagonistic behavior. Besides the boost in proteins involved in energetic metabolism, other changes in proteins related to cell envelope composition are implicated in the biocontrol abilities of both strains, and this might be to facilitate hyphal adhesion or biofilm formation. The results of this study are of great value because they promote a deep understanding of the proteins that undergo changes during yeast antagonistic interactions, but also because they provide new insights into the proteomes of non-Saccharomyces yeasts, which have not been previously described.