Hairy roots, their multiple applications and recent patents

In the last years, hairy root (HR) cultures are gaining attention in the biotechnology industry. This particular plant cell culture derives from explants infected with Agrobacterium rhizogenes. They constitute a relatively new approach to in vitro plant biotechnology and modern HR cultures are far away from the valuables findings performed by Philip R. White in the 1930´s, who obtained indefinite growth of excised root tips. HR cultures are characterized by genetic and biochemical stability and high growth rate without expensive exogenous hormones source. HR cultures have allowed a deep study of plant metabolic pathways and the production of valuable secondary metabolites and enzymes, with therapeutic or industrial application. Furthermore, the potential of HR cultures is increasing continuously since different biotechnological strategies such as genetic engineering, elicitation and metabolic traps are currently being explored for discovery of new metabolites and pathways, as well as for increasing metabolites biosynthesis and/or secretion. Advances in design of proper bioreactors for HR growth are being of great interest, since scale up of metabolite production will allow the integration of this technology to industrial processes. Another application of HR cultures is related to their capabilities to biotransform and to degrade different xenobiotics. In this context, removal assays using this plant model system are useful tools for phytoremediation assays, previous to the application in the field. This review highlights the more recent application of HRs and those new patents which show their multiple utilities.Fil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: González, Paola Solange. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Screening of plant growth-promoting traits in arsenic-resistant bacteria isolated from the rhizosphere of soybean plants from Argentinean agricultural soil

Aims: The purpose of this study was to investigate plantgrowth promoting traits in native and arsenic (As) highly-resistant bacterial strains isolated from the rhizosphere of soybean (Glycine max) plants grown in an Argentinean agricultural field. Methods: Determination of MICs (Minimum inhibitory concentration) was carried out on solid media supplemented with arsenite (As 3+) or arsenate (As 5+). Morphological, cultural, physiological, biochemical and molecular characterization, and in vitro determination of plant growth promoting (PGP) properties of As resistant isolates were carried out. Arsenic in soil samples was determined by ICP-OES while residual arsenic on post-removal culture medium and accumulation in cells were estimated by GF-AAS after wet acid digestion. Results: Isolated strains included γ-proteobacteria such as Enterobacter sp. and Pseudomonas sp., and actinobacteria as Rhodococcus sp. All bacterial strains grew in presence of very high arsenite -over 24mMand arsenate –over 400mM- concentrations. Pseudomonas sp. strains presented simultaneously several in vitro PGP traits, although Rhodococcus erythropolis AW3 did not display PGP traits. However, R. erythropolis AW3 was the most As resistant strain and removed and accumulated the greatest amounts of the metalloid. Conclusion: The presence of As resistant and plantgrowth promoting bacterial strains in the rhizosphere of Glycine max, in arsenic containing agricultural soil, suggest that they could potentially play an important role in plant-growth promotion in stressed conditions. These strains were able to remove and accumulate As from liquid media, thus they could be beneficial for sustainable crop production.Fil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Improving soybean growth under arsenic stress by inoculation with native arsenic-resistant bacteria

Certain metal (loid)-resistant bacteria that inhabit the rhizosphere have shown to improve plant growth and tolerance under toxic metal stress. In this study, we tested if six native, arsenic-resistant and plant growth promoting bacteria (PGPB) were able to enhance soybean (Glycine max L.) growth and modulate arsenic (As) uptake. As a previous work, we tested all single isolates and all possible binary combinations without arsenic stress to identify the combinations that would have the greatest plant growth promoting effect. In this study, a screening assay was performed with only five inoculation options selected after first stage (Pseudomonas sp. AW4, Pseudomonas sp. AW6, AW4+AW6, Rhodococcus sp. AW3+Pseudomonas sp. AW5 and Enterobacter sp. AW1+AW6). In both stages, inoculation was implemented by imbibition of soybean seeds with bacterial suspensions, and plant growth was carried out in pots using perlite as substrate in a chamber with controlled conditions. In the third stage, we performed similar assays, under As stress, using the three most promising inoculation options (AW4, AW6 and AW3+AW5). Treatments were performed by irrigation with 25 μM arsenite (As3+), 25 μM arsenate (As5+), 25 μM equimolar As3+/As5+ solution or water (control). Biometric and biochemical parameters indicated that inoculation with Pseudomonas sp. AW4 significantly promoted soybean growth under As3+/As5+ treatment and did not modified As accumulation pattern. Further field studies are needed to determine if some of these inoculation options are useful to improve in situ soybean growth under arsenic stress and could become a tool for the development of sustainable agriculture in As-impacted environments.Fil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Regis, Sofia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Armendariz, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentin

Effect of arsenic on tolerance mechanisms of two plant growth-promoting bacteria used as biological inoculants

Bacterial ability to colonize the rhizosphere of plants in arsenic (As) contaminated soils is highly important for symbiotic and free-living plant growth-promoting rhizobacteria (PGPR) used as inoculants, since they can contribute to enhance plant As tolerance and limit metalloid uptake by plants. The aim of this work was to study the effect of As on growth, exopolysaccharide (EPS) production, biofilm formation and motility of two strains used as soybean inoculants, Bradyrhizobium japonicum E109 and Azospirillum brasilense Az39. The metabolism of arsenate (As(V)) and arsenite (As(III)) and their removal and/or possible accumulation were also evaluated. The behavior of both bacteria under As treatment was compared and discussed in relation to their potential for colonizing plant rhizosphere with high content of the metalloid. B. japonicum E109 growth was reduced with As(III) concentration from 10. μM while A. brasilense Az39 showed a reduction of growth with As(III) from 500. μM. EPS and biofilm production increased significantly under 25. μM As(III) for both strains. Moreover, this was more notorious for Azospirillum under 500. μM As(III), where motility was seriously affected. Both bacterial strains showed a similar ability to reduce As(V). However, Azospirillum was able to oxidize more As(III) (around 53%) than Bradyrhizobium (17%). In addition, both strains accumulated As in cell biomass. The behavior of Azospirillum under As treatments suggests that this strain would be able to colonize efficiently As contaminated soils. In this way, inoculation with A. brasilense Az39 would positively contribute to promoting growth of different plant species under As treatment.Fil: Armendariz, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Biología Molecular. Sección Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Biología Molecular. Sección Química Biológica; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Medina, Maria Ines. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Agostini, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Universidad Nacional de Río Cuarto; Argentin

Biosorción de plomo sobre un nuevo material híbrido: estudios preliminares para preconcentración elemental

En los últimos años, el uso de biosorbentes ha tenido un rol protagónico en el desarrollo de métodos analíticos en el marco de la “Química Verde”, ya que no se los somete a ningún tipo de bioprocesamiento (ej. obtención de una enzima), son biodegradables y presentan la posibilidad de ser reutilizados.1 Entre varias estrategias de biosorción, la implementación de microorganismos en técnicas de preconcentración SPE con columnas y D-µ-SPE puede ser una alternativa muy eficiente para la determinación de elementos trazas, debido a que ofrecen una relación superficie/volumen elevada además de una variedad de grupos funcionales y sitios activos de unión en su superficie a través de los cuales los metales pueden retenerse eficientemente bajo condiciones adecuadas (ej. grupos -COOH, -NH2, -OH, -SH).2 En el caso de la D-µ-SPE con microorganismos, se requiere en muchos casos el empleo de ultracentrífugas para lograr la separación de fases, la cual no siempre está disponible en los laboratorios analíticos. En relación a la SPE con columnas, se han desarrollado varios trabajos que inmovilizan células microbianas sobre un soporte clásico (resinas de adsorción, materiales nanoestructurados).3 El objetivo del presente trabajo fue emplear un material híbrido enteramente biodegradable para estudiar su potencial adsortivo en una SPE en línea para preconcentración elemental. Inicialmente, se preparó un híbrido conformado por: a) raíces en cabellera de colza (Brassica napus), las cuales son muy interesantes desde el punto de vista biotecnológico debido a la gran cantidad de biomasa que puede obtenerse en tiempos cortos, por el rápido crecimiento que presentan, y b) Rodococcus Erytropolis AW3, la cual es una bacteria no patógena ampliamente encontrada en la naturaleza. El material biohíbrido fue caracterizado por FTIR y empleado como relleno de una microcolumna cilíndrica de vidrio de 1 mm de longitud y 2 mm de diámetro interno. Se evaluó el efecto de distintas variables experimentales sobre el porcentaje de retención del analito, obteniéndose una retención del analito del 100% bajo las siguientes condiciones: masa de biosorbente: 100 mg, pH: 4, caudal de carga: 1 ml/min. Se determinó la capacidad dinámica del biosorbente híbrido (36 mg/g), la cual potencia la reutilización de la columna durante varios ciclos de preconcentración. Se ensayaron diferentes concentraciones y volúmenes de HCl y HNO3 para la desorción de Pb desde el biosorbente, obteniéndose resultados óptimos a bajas concentraciones de eluyente. Se realizaron estudios de interferencias, considerando concentraciones de interferentes semejantes a las encontradas en muestras de bebidas analcohólicas. La retención del analito no fue interferida por la presencia de los concomitantes ensayados. Estos resultados preliminares abren puertas para el desarrollo de una SPE en línea para la preconcentración y determinación de Pb en muestras de alimentos.Fil: Quintas, Pamela Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; ArgentinaFil: Wevar Oller, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Agostini, Elisabet. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Escudero, Leticia Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; Argentina10° Congreso Argentino de Química AnalíticaSanta RosaArgentinaAsociación Argentina de Químicos AnalíticosUniversidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturale

Grain and Forage Legumes in an Arsenic-Polluted Agricultural Scenario

Grain and forage legumes have the potential to be a key component of climate-smart agriculture, even under arsenic (As) stress. Recent publications seem to indicate that agricultural practices with legumes can help in climate change mitigation and simultaneously in remediation of As contaminated areas. The legume-rhizobia symbiosis is one of the most beneficial interactions in the agricultural environment. First, since this symbiosis can improve soil structure, fertility and moisture retention through the incorporation of nitrogen, utilizing the biological nitrogen fixation (BNF) process, legumes have unique advantages to be used in crop rotation and intercropping schemes in pursuit of sustainability. On the other hand, legumes are able to grow in unfavorable environments, like those contaminated with toxic metal(loids). Among them, As is one of the most worldwide distributed non-essential metalloids, that induces different phytotoxic effects on plants and bacteria depending on its speciation, redox state, concentration, plant species, exposure time and repeated exposition. Recently, an interesting link between As and plant water status has been established and this aspect is particularly deepened here. Furthermore, inoculation of legumes with As-resistant rhizobia and/or other As-resistant plant growth promoting bacteria (PGPB) is increasingly being exploited as an As mitigation strategy. In this review, we provide a comprehensive description of the main effects of As on grain and forage legumes with a focus on water status changes and recent advances related with the potential of legume-rhizobia symbiosis under As stress in the climate-smart agriculture.Fil: Wevar Oller, Ana Laura. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Vezza, Mariana Elisa. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; Argentin

Biohybrid adsorbent for the preconcentration of lead and Its determination in fruit Juices by electrothermal atomic absorption spectrometry

Background: Fruit juices are one of the most non-alcoholic beverages consumed in the world. Essential elements and other nutrientspresent in fruit juices play an important role in human well-being. However, fruit juices may also contain potentially toxic elementsat trace levels, causing health risks.Objective: The objective of this work was to develop an analytical methodology based on the preconcentration of lead using a newbiodegradable hybrid material (BHM) composed of Rhodococcus erythropolis AW3 bacteria and Brassica napus hairy roots.Methods: The BHM was implemented in an online solid-phase extraction (SPE) system for the determination of lead in fruit juices byelectrothermal atomic absorption spectrometry (ETAAS).Results: Effects of critical parameters on lead retention were studied. Under optimal experimental conditions, extraction efficiencyhigher than 99.9% and an enrichment factor of 62.5 were achieved. The dynamic capacity of the BHM was 36 mg/g, which favored thereuse of the column for at least eight biosorptiondesorption cycles. The LOD and LOQ for preconcentration of 5mL of sample were5.0 and 16.5 ng/L lead, respectively. The RSD was 4.8% (at 1 mg/L lead and n¼10).Conclusion: The developed method was suitable for application to lead determination in different types of fruit juice.Highlights: A novel microextraction procedure based on the use of a biohybrid adsorbent. Highly sensitive determination of Pb attrace levels. Analysis of Pb in fruit juices samples. An eco-friendly microextraction technique for Pb determination.Fil: Quintas, Pamela Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; ArgentinaFil: Wevar Oller, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Escudero, Leticia Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentin

Application of hairy roots for phytoremediation: what makes them an interesting tool for this purpose?

In recent years, hairy roots (HRs) have been successfully used as research tools for screening the potentialities of different plant species to tolerate, accumulate, and/or remove environmental pollutants, such as PCBs, TNT, pharmaceuticals, textile dyes, phenolics, heavy metals, and radionuclides. This is in part due to several advantages of this plant model system and the fact that roots have evolved specific mechanisms to deal with pollutants because they are the first organs to have contact with them. In addition, by using HRs some metabolic pathways and enzymatic catalyzed reactions involved in pollutants detoxification can be elucidated as well as the mechanisms of uptake, transformation, conjugation, and compartmentation of pollutants in vacuoles and/or cell walls, which are important detoxification sites in plants. Plant roots also stimulate the degradation of contaminants by the release of root exudates and oxido-reductive enzymes, such as peroxidases (Px) and laccases, that are associated with the removal of some organic pollutants. HRs are also considered good alternatives as enzyme sources for remediation purposes. Furthermore, application of genetic engineering methods and development of microbe-assisted phytoremediation are feasible strategies to enhance plant capabilities to tolerate, accumulate, and/or metabolize pollutants and, hence, to create or find an appropriate plant system for environmental cleanup. The present review highlights current knowledge, recent progress, areas which need to be explored, and future perspectives related to the application and improvement of the efficiency of HRs for phytoremediation research.Fil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: González, Paola Solange. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Medina, Maria Ines. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Promising co-inoculation strategies to reduce arsenic toxicity in soybean

Arsenic (As) is cause for concern worldwide due to its high toxicity. Its presence in agricultural soils and groundwater adversely affects soybean (Glycine max L.) growth and yield, and also endangers food safety. Plant growth-promoting rhizobacteria (PGPR) could be used as part of cost-effective and eco-friendly strategies to mitigate As phytotoxicity. However, simple inoculation of soybean with PGPR Bradyrhizobium japonicum E109 (E109), a common practice in Argentina, is not effective in counteracting the effects of As exposure. Our aim was to assess whether the response of soybean to arsenate (AsV) and arsenite (AsIII) could be helpfully modulated by co-inoculating E109 with the free-living PGPRs Azospirillum brasilense Cd (Cd) or Bacillus pumilus SF5 (SF5). Co-inoculation with E109+SF5 alleviated As-induced depletion of chlorophyll a and b, and carotenoid content, reaching an increase of 26, 28 y 31%, respectively. It also enhanced nodulation (15-19%) under As exposure. E109+Cd and E109+SF5 induced changes in the antioxidant system, which could be related to the maintenance of redox homeostasis. Moreover, As accumulation was reduced by 53% in aerial parts of plants inoculated with E109+Cd, and by 16% in the roots of those inoculated with E109+SF5. The strains selected show interesting potential for the development of biotechnological schemes to improve soybean yield while guaranteeing safer food production.Fil: Vezza, Mariana Elisa. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pramparo, Romina del Pilar. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Wevar Oller, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Biotecnología Ambiental y Salud - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Biotecnología Ambiental y Salud; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effects of arsenate on tobacco hairy root and seedling growth, and its removal

Arsenic (As) is a highly toxic environmental contaminant to which most living organisms are exposed. Plants have evolved several mechanisms to cope with this toxic metalloid; however, these mechanisms are only partially understood. The response of plants to As phytotoxicity is highly complex, with considerable variation among species. In this study, arsenate (As+5) effects on germination and early root development of tobacco (Nicotiana tabacum) seedlings were investigated. Also, As+5 tolerance and removal efficiency of tobacco hairy roots (HRs) and seedlings were assessed and compared. Total seed germination capacity was not affected by 10 to 200 μM As+5, while primary root length and root branching were reduced by As+5 concentrations that were at or above 100 μM. Both systems were able to tolerate As+5 concentrations of 10 μM since no growth inhibition was detected. For higher As+5 concentrations, phytotoxicity increased, but it was mitigated by higher phosphate (Pi) availability. Under the studied conditions, As+5 removal efficiency of HRs greatly exceeded that of seedlings. Further, tobacco HRs were able to accumulate As in their tissues. These results justify further investigations on As tolerance and detoxification mechanisms in tobacco, an easy-to-transform crop species with high biomass, which could allow evaluation of the possible application of wild type or alternatively transgenic tobacco plants for As phytoextraction.Fil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wevar Oller, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez, Silvia Patricia. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica. Area de Quimica Analitica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oliva González, María Soledad. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica. Area de Quimica Analitica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin