Open Access
High-density seedling expression system for the production of bioactive human cardiotrophin-1, a potential therapeutic cytokine, in transgenic tobacco chloroplasts
(Wiley, 2008) Farrán Blanch, Inmaculada; Río-Manterola, Francisco; Íñiguez, María; Gárate, Sonia; Prieto, Jesús; Mingo Castel, Ángel; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, “Formación de Tecnólogos” 055/01/11. M.N.C
Histidine‐tagged human cardiotrophin‐1 (hCT‐1), a recently discovered cytokine with excellent therapeutic potential, was expressed in tobacco chloroplasts under the transcriptional and translational control of two different promoters (rrn and psbA) and 5′‐untranslated regions (5′‐UTRs) (psbA and phage T7 gene 10). The psbA 5′‐UTR promotes recombinant hCT‐1 (rhCT‐1) accumulation in chloroplasts at higher levels (eight‐fold) than those obtained for the phage T7 gene 10 5′‐UTR, regardless of the promoter used, indicating that the correct choice of translational control element is most important for protein production in chloroplasts. The maximum level of rhCT‐1 achieved was 1.14 mg/g fresh weight (equivalent to 5% of total soluble protein) with the psbA promoter and 5′‐UTR in young leaves harvested after 32 h of continuous light, although the bioactivity was significantly lower (~35%) than that of commercial hCT‐1. However, harvesting in the dark or after 12 h of light did not result in a significant decrease in the bioactivity of rhCT‐1, suggesting that 32 h of over‐lighting affects the biological activity of rhCT‐1. Because high levels of rhCT‐1 accumulation took place mainly in young leaves, it is proposed that seedlings should be used in a ‘closed system’ unit, yielding up to 3.2 kg per year of rhCT‐1. This amount would be sufficient to meet the estimated annual worldwide needs of hCT‐1 for liver transplantation surgery in a cost‐effective manner. Furthermore, our strategy is an environmentally friendly method for the production of plant‐based biopharmaceuticals.
Open Access
Converging pathways: new approaches to integrate vocational education training and higher education
(Routledge, 2024-11-14) Farrán Blanch, Inmaculada; Núñez Aldaz, Imanol; Institute for Advanced Research in Business and Economics - INARBE; Institute for Multidisciplinary Research in Applied Biology - IMAB
The evolving professional landscape necessitates educational innovation to prepare students for emerging challenges. This paper explores the integration of Vocational Education and Training (VET) and Higher Education (HE) through double-degree programs, challenging the conventional perception of these pathways as independent. Recognising the transformative potential in synergising competencies from VET and HE, we advocate for enhancing students' employability through collaborative curriculum design and shared learning objectives. Addressing limitations in the current VET-to-HE transition, we identify four criteria for successful double programs (i) coherent competency map, (ii) unified methodology, (iii) distinctive profile, (iv) own signalling. The paper concludes with a case study of an emerging dual VET/HE program in Navarra (Spain) built on the criteria outlined above.
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
Metschnikowia pulcherrima as an efficient biocontrol agent of Botrytis cinerea infection in apples: unraveling protection mechanisms through yeast proteomics
(Elsevier, 2023) Fernández San Millán, Alicia; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Larraya Reta, Luis María; Farrán Blanch, Inmaculada; Veramendi Charola, Jon; Ciencias de la Salud; Osasun Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The results obtained in this study show that the Mp-30 strain of Metschnikowia pulcherrima is able to completely prevent Botrytis cinerea infection in apples, which is a major postharvest disease of fruits throughout the world. We have observed that although Mp-30 is able to rapidly colonize wounds, sequestrate iron and secrete antifungal compounds, other unknown mechanisms that occur in the early phase of the yeast-fungal interaction must be implicated in the biocontrol response. The main objective of this study was to identify the pathways involved in the mechanism of action of Mp-30 against B. cinerea in apples. Therefore, differentially accumulated yeast proteins in the presence/absence of B. cinerea on wounded apples were studied to elucidate Mp-30 biocontrol mechanisms and regulation at the protein level. A comparative proteomic analysis showed that 114 yeast proteins were increased and 61 were decreased. The Mp-30 antagonistic response mainly showed the increase of (1) gene expression and protein translation related proteins, (2) trafficking and vesicle-mediated transport related proteins, (3) pyruvate metabolism and mitochondrial proteins related to energy and amino acid production, (4) fatty acid synthesis, and (5) cell envelope related proteins. On the other hand, redox homeostasis, and amino acid and carbon metabolism were downregulated. Since there is no yeast growth enhancement associated with the presence of B. cinerea, such regulation mechanisms may be related to the reprogramming of metabolism, synthesis of new compounds and reorganization of yeast cell structure. Indeed, the results show that several pathways cooperate in restructuring the plasma membrane and cell wall composition, highlighting their major role in the antagonistic interactions for apple protection against gray mold proliferation. These results are of great interest since they provide a clear insight into the yeast mechanisms involved in B. cinerea inactivation during the first hours of contact in the wounded fruit. They shed light on the unknown yeast molecular biocontrol mechanisms.
Open Access
Towards understanding of fungal biocontrol mechanisms of different yeasts antagonistic to Botrytis cinerea through exometabolomic analysis
(Elsevier, 2022) Fernández San Millán, Alicia; Gamir, Jordi; Larraya Reta, Luis María; Farrán Blanch, Inmaculada; Veramendi Charola, Jon; Institute for Multidisciplinary Research in Applied Biology - IMAB; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
There is increased interest in research on yeasts as potential phytopathogen biocontrol agents due to increasing restrictions in the use of chemical pesticides. Yeast strains from a range of genera and species have been reported to inhibit postharvest decay in different fruits. However, the mechanisms behind these yeast biocontrol capacities have not been completely deciphered because they are complex and act synergistically. In this study, we performed a thorough untargeted analysis of the exometabolome generated in a co-culture of the fungal plant pathogen Botrytis cinerea with four antagonistic yeast strains: Pichia fermentans (two strains), Issatchenkia terricola and Wickerhamomyces anomalus. As a result, general and strain-specific antifungal mechanisms and molecules were identified. The P. fermentans strains secreted the highest number of differential metabolites to the extracellular medium when co-cultured with B. cinerea. In vitro antagonistic and in vivo pathogen protection assays were performed with the selected metabolites. Among a plethora of 46 differentially secreted metabolites related to yeast-fungus competitive interaction, the phenylpropanoid trans-cinnamic acid and the alkaloid indole-3-carboxaldehyde were identified as the best antagonistic metabolites against gray mold infection under in vivo protection assays. Both metabolites caused damage to the fungal membrane and increased ROS generation in spores of B. cinerea. In addition, enhanced yeast secretion to the extracellular medium of oxylipins, dipeptides, alkaloids or antibiotics deserve to be further investigated as signaling or antagonistic molecules. This study opens the door to future investigations of roles of these molecules in yeast metabolism and application of this knowledge for biotechnological purposes.
Open Access
Expression of recombinant proteins lacking methionine as N-terminal amino acid in plastids: human serum albumin as a case study
(Elsevier, 2007) Fernández San Millán, Alicia; Farrán Blanch, Inmaculada; Molina Azcona, Andrea; Mingo Castel, Ángel; Veramendi Charola, Jon; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Open Access
New in vivo approach to broaden the thioredoxin family interactome in chloroplasts
(MDPI, 2022) Ancín Rípodas, María; Fernández Irigoyen, Joaquín; Santamaría Martínez, Enrique; Larraya Reta, Luis María; Fernández San Millán, Alicia; Veramendi Charola, Jon; Farrán Blanch, Inmaculada; Ciencias de la Salud; Osasun Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB
Post-translational redox modifications provide an important mechanism for the control of major cellular processes. Thioredoxins (Trxs), which are key actors in this regulatory mechanism, are ubiquitous proteins that catalyse thiol-disulfide exchange reactions. In chloroplasts, Trx f, Trx m and NADPH-dependent Trx reductase C (NTRC) have been identified as transmitters of the redox signal by transferring electrons to downstream target enzymes. The number of characterised Trx targets has greatly increased in the last few years, but most of them were determined using in vitro procedures lacking isoform specificity. With this background, we have developed a new in vivo approach based on the overexpression of His-tagged single-cysteine mutants of Trx f, Trx m or NTRC into Nicotiana benthamiana plants. The over-expressed mutated Trxs, capable of forming a stable mixed disulfide bond with target proteins in plants, were immobilised on affinity columns packed with Ni-NTA agarose, and the covalently linked targets were eluted with dithiothreitol and identified by mass spectrometry-based proteomics. The in vivo approach allowed identification of 6, 9 and 42 new potential targets for Trx f, Trx m and NTRC, respectively, and an apparent specificity between NTRC and Trxs was achieved. Functional analysis showed that these targets are involved in several cellular processes.
Open Access
Successful biocontrol of major postharvest and soil-borne plant pathogenic fungi by antagonistic yeasts
(Elsevier, 2021) Fernández San Millán, Alicia; Larraya Reta, Luis María; Farrán Blanch, Inmaculada; Ancín Rípodas, María; Veramendi Charola, Jon; Institute for Multidisciplinary Research in Applied Biology - IMAB; Gobierno de Navarra / Nafarroako Gobernua
Fungal pathogens are the main biotic burden of productivity for economically important crops under field, greenhouse or postharvest conditions. The discovery and development of new environmental-friendly solutions, such as application of living organisms and their derivatives to control plant diseases and pests, are of enormous interest. This study presents the results of a mass screening designed to detect yeast strains with antagonistic activity against postharvest pathogens (Alternaria alternata, Penicillium expansum and Botrytis cinerea) and soil-borne diseases (Verticillium dahliae and Fusarium oxysporum). In fact, this is the first study that focuses on screening the antagonistic potential of a wide variety of yeast genera (13) and species (30) against vascular wilts. The results from in vivo trials demonstrated that fungal infected tomato plants, grown under hydroponic or soil conditions, showed a significant reduction in disease severity after yeast treatment. Wickerhamomyces anomalus Wa-32 was able to antagonise both pathogens and reduce the disease severity up to 40% (V. dahliae) and 50% (F. oxysporum) in soil conditions. In addition, this strain became endophytic in tomato plants. The features of Wa-32 are of enormous interest since no effective antagonistic biocontrol product is available for the simultaneous control of these two fungal pathogens. Postharvest assays with wounded tomato fruits showed that several strains displayed very high biocontrol levels against P. expansum and B. cinerea (up to 86 and 97% reduction in disease severity, respectively) but none of them showed protection against A. alternata. The best protection against B. cinerea was again achieved with W. anomalus Wa-32 and two Metschnikowia pulcherrima strains (Mp-22 and Mp-30). However, the best antagonistic strains of P. expansum were Candida lusitaniae Cl-28, Candida oleophila Co-13, Debaryomyces hansenii Dh-67 and Hypopichia pseudoburtonii Hp-54. These biocontrol effects were also demonstrated in grapes and apples.
Open Access
Identification of new antifungal metabolites produced by the yeast Metschnikowia pulcherrima involved in the biocontrol of postharvest plant pathogenic fungi
(Elsevier, 2022) Fernández San Millán, Alicia; Gamir, Jordi; Farrán Blanch, Inmaculada; Larraya Reta, Luis María; Veramendi Charola, Jon; Institute for Multidisciplinary Research in Applied Biology - IMAB; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Several strains of the yeast Metschnikowia pulcherrima exhibit strong antagonistic activity against postharvest pathogens and may have broad biotechnological potential as biocontrol agents. However, the nature and interplay of the mechanisms contributing to this antifungal activity are still largely unknown. This study characterizes the antifungal compounds present in the exometabolome of two yeast strains that previously showed an efficient inhibition of Botrytis cinerea infection. We show that a yeast-fungus co-culture assay is a good system to examine the antagonistic interaction and elucidate the nature of the produced yeast metabolites. As a result, our UPLC-MS/MS analysis identified a total of 35 differentially secreted metabolites, potentially involved in the biocontrol of gray mold. Subsequent in vitro analysis and in vivo tomato, grape and apple fruit protection assays with such metabolites allowed us to identify several new antifungal compounds, with 3-amino-5-methylhexanoic acid, biphenyl-2,3-diol and sinapaldehyde being the most active (with up to 90–100% reduction in the infection of tomato and apple with B. cinerea). In addition, the first two metabolites protected tomatoes against Alternaria alternata infection. It was observed that these metabolites negatively affected the cell membrane integrity and mycelial morphology of B. cinerea and increased the intracellular level of ROS. Furthermore, other unexpected metabolites with interesting biotechnological applications were identified for the first time as being secreted by yeast cells, such as piperideine and protoemetine (alkaloids), p-coumaroyl quinic acid (phenylpropanoid), β-rhodomycin (antibiotic), hexadecanedioic acid (long chain fatty acid) or taurocholic acid (bile acid). This fact highlights that the antifungal activity of M. pulcherrima may result from synergistic action of several active molecules.
Open Access
Overexpression of plastidial thioredoxins f and m differentially alters photosynthetic activity and response to oxidative stress in tobacco plants
(Frontiers Media, 2013) Rey, Pascal; Sanz Barrio, Ruth; Innocenti, Gilles; Ksas, Brigitte; Courteille, Agathe; Rumeau, Dominique; Issakidis Bourguet, Emmanuelle; Farrán Blanch, Inmaculada; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Plants display a remarkable diversity of thioredoxins (Trxs), reductases controlling the thiol redox status of proteins. The physiological function of many of them remains elusive, particularly for plastidial Trxs f and m, which are presumed based on biochemical data to regulate photosynthetic reactions and carbon metabolism. Recent reports revealed that Trxs f and m participate in vivo in the control of starch metabolism and cyclic photosynthetic electron transfer around photosystem I, respectively. To further delineate their in planta function, we compared the photosynthetic characteristics, the level and/or activity of various Trx targets and the responses to oxidative stress in transplastomic tobacco plants overexpressing either Trx f or Trx m. We found that plants overexpressing Trx m specifically exhibit altered growth, reduced chlorophyll content, impaired photosynthetic linear electron transfer and decreased pools of glutathione and ascorbate. In both transplastomic lines, activities of two enzymes involved in carbon metabolism, NADP-malate dehydrogenase and NADP-glyceraldehyde-3-phosphate dehydrogenase are markedly and similarly altered. In contrast, plants overexpressing Trx m specifically display increased capacity for methionine sulfoxide reductases, enzymes repairing damaged proteins by regenerating methionine from oxidized methionine. Finally, we also observed that transplastomic plants exhibit distinct responses when exposed to oxidative stress conditions generated by methyl viologen or exposure to high light combined with low temperature, the plants overexpressing Trx m being notably more tolerant than Wt and those overexpressing Trx f. Altogether, these data indicate that Trxs f and m fulfill distinct physiological functions. They prompt us to propose that the m type is involved in key processes linking photosynthetic activity, redox homeostasis and antioxidant mechanisms in the chloroplast.