Estrategias aplicadas a la enseñanza teórico-práctica de Fisiología Vegetal mediante la tecnología B-Learning

En el marco de las XII Jornadas de Redes de Investigación en Docencia Universitaria 2014, de la Universidad de Alicante, se creó una red de trabajo formada por los profesores de la asignatura “Fisiología vegetal: Nutrición, transporte y metabolismo” del segundo curso del Grado en Biología. Durante la implementación de la asignatura, se puso de manifiesto la necesidad de revisar aspectos metodológicos con el fin de mejorar el aprendizaje de los alumnos, introduciendo para ello, innovaciones vía recursos tecnológicos de última generación. De esta forma, se incorporó la tecnología B-Learning, a través de sesiones docentes, con el propósito de mejorar la interacción profesor-alumno en la enseñanza presencial y virtual y coordinar la parte teórica y práctica de la asignatura. Este estudio permitió evaluar la nueva metodología docente aplicada, comparando las ventajas e inconvenientes de ésta con la tradicional, a partir de encuestas realizadas a los alumnos, con preguntas referidas a sus características personales y a su desempeño en la Universidad, así como a su valoración de la metodología docente propuesta. Además, también se pretendió estudiar las estrategias que mejor resultado dieran, para aplicarlas en futuros cursos

Sistemas de aprendizaje y análisis de resultados en la asignatura Fisiología Vegetal

En el marco de la convocatoria de los proyectos de redes de investigación en docencia universitaria 2014-2015, de la Universidad de Alicante, se creó una red de trabajo formada por los profesores de la asignatura “Fisiología Vegetal: Nutrición, Transporte y Metabolismo” del segundo curso del Grado en Biología. En esta red se pretende evaluar el sistema de enseñanza/aprendizaje que se realiza en la asignatura desde la implantación de los grados. Para alcanzar este objetivo se van a analizar los resultados académicos que los alumnos/as matriculados/as en la asignatura han alcanzado en las diferentes pruebas de evaluación continua y final que se realizan. Además, se examinará si existe una relación entre el grado de participación del alumnado en la asignatura y la calificación obtenida. Los resultados de esta investigación permitirán mejorar el sistema de evaluación utilizado a fin de que resulte más eficiente

Uso de la metodología B-Learning en la enseñanza teórico-práctica de Fisiología Vegetal

Con la incorporación de las Universidades al Espacio Europeo de Educación Superior (EEES), se ha fomentado la investigación en Docencia Universitaria y, sobre todo, en la incorporación de las nuevas tecnologías, lo cual representa un pilar base para incrementar la calidad de la docencia. Por todo ello, en la convocatoria 2013-2014 de Redes de Investigación en Docencia Universitaria, de la Universidad de Alicante, se decidió crear una red de trabajo que se centrara en estudiar una nueva metodología educativa en la asignatura “Fisiología vegetal: Nutrición, transporte y metabolismo”, que se imparte en el segundo curso del Grado en Biología de esta misma universidad. En esta Red se incorporó la tecnología B-Learning, a través de sesiones docentes, con el propósito de mejorar la interacción profesor-alumno. Una vez finalizada la experiencia, se evaluó esta nueva metodología a través de encuestas docentes a los alumnos que sirvieron para comparar las ventajas e inconvenientes de la metodología B-Learning con la tradicional

Evaluación del trabajo colaborativo en Iniciación a la Investigación en Biología

Tras el trabajo previo de diseño de la asignatura Iniciación a la Investigación en Biología, el equipo multidisciplinar de profesores y profesoras de la Red Docente INVES ha desarrollado una metodología propia de trabajo en equipo, no sólo entre el diferente profesorado que la compone, sino también con el profesorado de la asignatura Estadística, con la que se comparten objetivos de aprendizaje comunes. Se ha optimizado el sistema de evaluación del trabajo colaborativo del alumnado, mediante el uso de rubricas y auto-evaluación. Dicho trabajo consiste en el diseño y desarrollo de un proyecto de investigación bibliométrico de temática biológica realizado por los estudiantes, propiciando la adquisición de competencias transversales mediante una dinámica de trabajo en grupo que culmina en la edición de unas Jornadas Científicas. Por otra parte, se han consensuado criterios comunes de evaluación continua, mejorando en la eficiencia de la evaluación, y determinado un incremento de la capacidad de aprendizaje del alumnado a lo largo de los cursos 2010-11 al 2013-14. La oferta formativa se completa mediante la formación de un grupo de Alto Rendimiento Académico con docencia en lengua inglesa. Esto permite al alumnado implementar el objetivo general de compresión de lengua extranjera inglés en lo relativo al ámbito científico

Avances en el trabajo colaborativo en Iniciación a la Investigación en Biología

Un equipo multidisciplinar de profesores y profesoras que componen la Red Docente INVES e imparten docencia en la asignatura Iniciación a la Investigación en Biología, ha desarrollado una metodología propia de trabajo en equipo, en coordinación con el profesorado de la asignatura Estadística, con la que se comparten objetivos de aprendizaje comunes. El sistema de evaluación del trabajo colaborativo del alumnado se ha optimizado mediante el uso de rúbricas y auto-evaluación. Se ha propiciado la adquisición de competencias transversales mediante una dinámica de trabajo en grupo. El diseño y desarrollo de un proyecto de investigación bibliométrico, de temática biológica, es realizado por los y las estudiantes, y culmina con la edición de unas Jornadas Científicas. Con el fin de mejorar la eficiencia de la evaluación, se han consensuado criterios comunes de evaluación continua entre el profesorado. Ello ha determinado un incremento de la capacidad de aprendizaje del alumnado a lo largo de los cursos 2010-11 al 2013-14. La lectura y compresión de textos científicos en inglés junto a la formación de un grupo de Alto Rendimiento Académico con docencia en lengua inglesa completa la oferta formativa, permitiendo al alumnado implementar el objetivo general de compresión de lengua extranjera inglés en lo relativo al ámbito científico

Metabolic engineering to simultaneously activate anthocyanin and proanthocyanidin biosynthetic pathways in Nicotiana spp

[EN] Proanthocyanidins (PAs), or condensed tannins, are powerful antioxidants that remove harmful free oxygen radicals from cells. To engineer the anthocyanin and proanthocyanidin biosynthetic pathways to de novo produce PAs in two Nicotiana species, we incorporated four transgenes to the plant chassis. We opted to perform a simultaneous transformation of the genes linked in a multigenic construct rather than classical breeding or retransformation approaches. We generated a GoldenBraid 2.0 multigenic construct containing two Antirrhinum majus transcription factors (AmRosea1 and AmDelila) to upregulate the anthocyanin pathway in combination with two Medicago truncatula genes (MtLAR and MtANR) to produce the enzymes that will derivate the biosynthetic pathway to PAs production. Transient and stable transformation of Nicotiana benthamiana and Nicotiana tabacum with the multigenic construct were respectively performed. Transient expression experiments in N. benthamiana showed the activation of the anthocyanin pathway producing a purple color in the agroinfiltrated leaves and also the effective production of 208.5 nmol (-) catechin/g FW and 228.5 nmol (-) epicatechin/g FW measured by the p-dimethylaminocinnamaldehyde (DMACA) method. The integration capacity of the four transgenes, their respective expression levels and their heritability in the second generation were analyzed in stably transformed N. tabacum plants. DMACA and phoroglucinolysis/HPLC-MS analyses corroborated the activation of both pathways and the effective production of PAs in T0 and T1 transgenic tobacco plants up to a maximum of 3.48 mg/g DW. The possible biotechnological applications of the GB2.0 multigenic approach in forage legumes to produce "bloatsafe" plants and to improve the efficiency of conversion of plant protein into animal protein (ruminal protein bypass) are discussed.This work was supported by grants BIO2012-39849-C02-01 and BIO2016-75485-R from the Spanish Ministry of Economy and Competitiveness (MINECO) (http://www.idi.mineco.gob.es/portal/site/MICINN) to LAC and a fellowship of the JAE-CSIC program to SF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Fresquet-Corrales, S.; Roque Mesa, EM.; Sarrión-Perdigones, A.; Rochina, M.; López-Gresa, MP.; Díaz-Mula, HM.; Belles Albert, JM.... (2017). Metabolic engineering to simultaneously activate anthocyanin and proanthocyanidin biosynthetic pathways in Nicotiana spp. PLoS ONE. 12(9). https://doi.org/10.1371/journal.pone.0184839Se018483912

Bioactive compounds, antioxidant activity and quality of plum and sweet cherry cultivars as affected by ripening on-tree, cold storage and postharvest treatments

Plum and sweet cherry are one of the most important stone fruits grown commercially in Spain and are of the most important commodities consumed worldwide due to their excellent quality attributes and high degree of acceptation by consumers. However, these fruits are highly perishable and the application of cold storage and other postharvest technologies are therefore necessary to maintain fruit quality from harvest to consumption. In this Thesis a comparative study on the evolution of physical, chemical and nutritive parameters and bioactive compounds during development and on-tree ripening and postharvest cold storage was performed in a wide range of plum ad sweet cultivars.Eight plum cultivars: 4 purple (‘Angeleno’, ‘Blackamber’, ‘Black Diamond’ and ‘Larry Ann’) and 4 yellow (‘Golden Japan’, ‘Golden Globe’, ‘Songold’ and ‘TC Sun’) skin coloured, and 11 sweet cherry cultivars: ‘Brooks’, ‘Cristalina’, Newstar’, ‘Nº 57’, ‘NY-6479’, ‘Prime Giant’, ‘Santina’, Somerset’, ‘Sonata’, ‘Sunburst’ and ‘Sweetheart’ were chosen. During on-tree ripening fruit weight evolution demonstrated the double-sigmoid growth pattern for all plum and sweet cherry cultivars and the main changes related to ripening, such as colour, total soluble solids (TSS), total acidity (TA), firmness started at early stages of fruit development, with significant differences among cultivars. The decrease in colour Hue angle was highly correlated with the increase in carotenoids in yellow plums and with total anthocyanins in purple plums and sweet cherries, showing that carotenoids are the main chemical compounds responsible for colour changes from green to orange/yellow occurring during ripening of the yellow plum cultivars, while anthocyanins were the main pigments of sweet cherry and purple plum cultivars. This correlation was found either during on-tree ripening or during cold storage. In sweet cherry the major anthocyanin was cyanidin-3-rutinoside followed by cyanidin-3-glucoside and pelargonidin 3-rutinoside, while the hydroxycinnamic acids derivatives neochlorogenic acid and 3’-p-coumaroylquinic acid were the main phenolic compounds. The cold storage of plums and sweet cherries induced a delay in fruit metabolism although the ripening process went on measured by the decrease in acidity, the increase in TSS and softening as well as the ethylene production in those plum cultivars that showed a climacteric-ripening pattern (‘Blackamber’, ‘Larry Ann’, ‘Golden Globe’ and ‘Songold’). In addition, the cold storage experiment in sweet cherry was performed with fruits harvested at 3 ripening stages (S1, S2, and S3), showing that at the end of storage time (16 days of cold storage + 2 days at 20 ºC) sweet cherries harvested at S1 reached the ripening stage of S2 at harvest, but the fruits picked at S2 did not get the ripening stage of S3 at harvest. Total antioxidant activity (TAA) due to hydrophilic (H-TAA) and lipophilic (L-TAA) compounds increased during on-tree ripening and during cold storage in all the plum and sweet cherry cultivars assayed, and were correlated to total phenolics and total carotenoids, respectively, demonstrating that phenolics are the main hydrophilic compounds contributing to H-TAA while the lipophilic nature of carotenoids contributed to L-TAA. It was found that at the usual commercial harvest dates for these cultivars do not assure the highest content of bioactive compounds and related antioxidant activity, since a delay of 7 or 4 days led to increases in these phytochemicals and TAA, for plums and cherries, respectively. The effect of modified atmosphere packaging (MAP) on maintaining plum quality was assayed on 4 plum cultivars (2 with yellow skin, ‘Golden Globe’ and ‘Songold’, and 2 with purple skin, ‘Blackamber’ and ‘Larry Ann’) thermo-sealed in baskets with 2 distinct films with medium (film M) and high (film H) gas permeability. Fruit stored with macroperforated film served as a control and lost their quality attributes very rapidly, manifested by accelerated colour changes, softening, decrease in acidity and increase in TSS. The use of MAP retarded these changes, the efficacy being higher in the fruit packed with film M compared with film H as a result of the delay in postharvest ripening, which could be attributed to the effect of MAP on reducing ethylene production rates. With the use of these packages, the storage time with fruit having high quality attributes could be increased 3–4 weeks more as compared with control plums. The changes in bioactive compounds (total phenolics and total carotenoids, and individual anthocyanins) as well as H-TAA and L-TAA in the peel and the flesh of these plum cultivars during storage under MAP conditions were studied. Results revealed that in all cultivars, total phenolics and H-TAA increased in the peel and flesh during storage, as well as the two identified anthocyanins: cyanidin-3-glucoside and cyanidin-3-rutinoside in the purple cultivars. These changes were significantly delayed in fruit stored under MAP conditions. Total carotenoids and L-TAA increased in the yellow cultivars (in both peel and flesh) while decreases were observed in the purple cultivars, these changes were also delayed by the use of MAP. Positive correlations were found between H-TAA and total phenolics and between L-TAA and total carotenoids. Results suggest that MAP does not impart any negative effects on TAA or phytochemicals and just reflects the delay of the ripening process occurring in the plums stored under MAP conditions, which led to an increase of the storage time with fruit having high quality attributes of 3-4 weeks more as compared with control plums. Postharvest treatment with salicylic acid (SA), acetylsalicylic acid (ASA) or oxalic acid (OA) at 1 mM were performed on ‘Cristalina’ and ‘Prime Giant’ sweet cherry cultivars harvested at commercial ripening stage and then fruits were stored for 20 days under cold temperature. These treatments delayed the postharvest ripening process, manifested by lower losses in acidity and firmness, lower color changes, and higher quality attributes maintenance in treated cherries as compared with controls. In addition, total phenolics, anthocyanins and antioxidant activity increased in untreated fruit during the first 10 days of storage and then decreased, while in fruits of all treatments, these parameters increased continuously during storage without significant differences among treatments. Thus, postharvest treatments with natural compounds, such as SA, ASA or OA, could be innovative tools to extend the storability of sweet cherry with higher content of bioactive compounds and antioxidant activity as compared with control fruits. Finally, another postharvest treatment was an edible coating based on sodium alginate applied at several concentrations (1, 3 or 5% w/v) in ‘Sweetheart’ cherry cultivar harvested at commercial maturity stage. A significant delay in the evolution of the parameters related to postharvest ripening, such as colour, softening and loss of acidity, and reducing respiration rate, was obtained in alginate-coated fruits. In addition, the edible coatings showed a positive effect on maintaining higher concentration of total phenolics and TAA, which decreased in control fruits associated with the over-ripening and senescence processes. Overall, the results obtained from quality parameters and antioxidant activity suggested that the maximum storability period for alginate-coated cherries with optimal quality and enhanced antioxidant activity could be extended up to 16 days at 2°C plus 2 days at 20°C, while this period for control fruits was only 8 days at 2°C plus 2 days at 20°

Expression analyses of transgenes and key genes involved in the anthocyanin biosynthetic pathway in transgenic <i>Nicotiana tabacum</i> leaves.

<p><b>(A)</b> qRT–PCR analysis of <i>AmRosea1</i>, <i>AmDelila</i>, <i>MtANR</i> and <i>MtLAR</i> transgenes in transformed leaves of <i>N</i>. <i>tabacum</i>. Error bars correspond to the standard deviation of three replicates. The expression value of <i>AmRosea1</i> in plant Nt#5 was set to 1.00 and the expression levels of the rest of transgenes were plotted relative to this value. To normalize the samples the constitutive <i>NtACT8</i> gene was used. <b>(B)</b> RT-PCR expression analysis of key genes involved in the anthocyanin pathway in <i>N</i>. <i>tabacum</i> Nt#6 and Nt#7 transgenic plants. PCR results were obtained after 30 amplification cycles for all genes and 25 cycles for the housekeeping <i>NtACT8</i> gene.</p

Relationship between purple phenotype, transgene expression and PAs production in three T1 <i>Nicotiana tabacum</i> plants.

<p><b>A-D.</b> Different leaf coloured phenotypes in the T1 of <i>N</i>. <i>tabacum</i> transgenic plants Nt#6.1 (green), Nt#6.8 (purple spots), Nt#6.11 (purple patches) and Nt#7.6 (full purple). <b>E.</b> In the lineage of plants Nt#6 and Nt#7 we analyzed by semi-qRT-PCR three plants with the complete set of transgenes showing a weak (Nt#6.8), a middle (Nt#6.11) and a strong purple phenotype (Nt#7.6). In the three plants the four transgenes were properly expressed. To normalize the samples the constituve <i>NtACT8</i> gene was used. <b>F.</b> The Nt#6.11, Nt#6.8 and Nt#7.6 transgenic plants produced PAs as demonstrated by HPLC-MS analysis of leaf extracts when compared with the WT.</p