Carolina Iturra

Universidad de Atacama, San Pedro de Atacama, Antofagasta, Chile

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Publications (6)8.13 Total impact

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    ABSTRACT: The gene coding for F5H from Eucalyptus globulus was cloned and used to transform an f5h -mutant of Arabidopsis thaliana , which was complemented, thus verifying the identity of the cloned gene. Coniferaldehyde 5-hydroxylase (F5H; EC 1.14.13) is a cytochrome P450-dependent monooxygenase that catalyzes the 5-hydroxylation step required for the production of syringyl units in lignin biosynthesis. The Eucalyptus globulus enzyme was characterized in vitro, and results showed that the preferred substrates were coniferaldehyde and coniferyl alcohol. Complementation experiments demonstrated that both cDNA and genomic constructs derived from F5H from E. globulus under the control of the cinnamate 4-hydroxylase promoter from Arabidopsis thaliana, or a partial F5H promoter from E. globulus, can rescue the inability of the A. thaliana fah1-2 mutant to accumulate sinapate esters and syringyl lignin. E. globulus is a species widely used to obtain products that require lignin removal, and the results suggest that EglF5H is a good candidate for engineering efforts aimed at increasing the lignin syringyl unit content, either for kraft pulping or biofuel production.
    Plant Cell Reports 04/2014; · 2.94 Impact Factor
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    ABSTRACT: One hundred genotypes of Eucalyptus globulus were ranked according to specific consumption of wood (cubic meters of wood needed to produce 1 ton of pulp). Ten of the most contrasting genotypes were separated in two groups of five clones each; group 1 (G1) with high wood density, high pulp yield, and low specific consumption, and group 2 (G2) with low density, low pulp yield, and high specific consumption. The contrasting genotypes also had significant differences in lignin content, percent syringyl unit composition, and frequency of β-O-4 linkages. Gene expression for phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), 4-coumarate:CoA ligase (4CL) and ferulate 5-hydrolase (F5H) was analyzed in the contrasting genotypes. In both groups, transcript abundance for CAD, PAL, and 4CL were similar and only F5H presented significant differences between groups, with high values in the best ranked genotypes G1 in comparison to G2. Correlations between traits were estimated for lignin content vs. pulp yield (R 2 = 0.97), pulp yield vs. syringyl units (R 2 = 0.82), β-O-4 linkages vs. pulp yield (R 2 = 0.84), and β-O-4 linkages vs. syringyl units (R 2 = 0.97). Correlations between chemical composition and transcript abundance for F5H were calculated, finding correlation values with lignin content (R 2 = 0.81), syringyl units (R 2 = 0.83), and pulp yield (R 2 = 0.81). The measurement of transcript abundance of F5H represents a potential genomic tool for tree improvement programs to select trees with high pulp yield. KeywordsLignin biosynthesis–F5H–Transcript abundance– Eucalyptus globulus –Pulp yield–Syringyl units
    Tree Genetics & Genomes 01/2011; 7(4):697-705. · 2.40 Impact Factor
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    ABSTRACT: The present research is based on the need to evaluate the impact of the Problem-Based-Learning (PBL) on the initial teacher education at the Facultad de Humanidades y Educación at the Universidad de Atacama. To achieve this objective, the first two cohorts of students that graduated after the implementation of the new curricula including this approach were chosen (2000-2001). The purpose is to look for evidences that show the competences developed during the education process and that could be related to the aims of working with PBL as well as to its influence in the professional performance. The results of this research link the PBL approach directly to the development of the competencies necessary for the proper insertion in teamwork.
    Estudios pedagógicos (Valdivia). 12/2010; 37(1):167-185.
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    ABSTRACT: En este trabajo hemos analizado una misma situación educativa desde una doble perspectiva. En concreto, hemos analizado la interacción que mantuvo una profesora de 6º de Educación Primaria con sus alumnos utilizando, por un lado, el Sistema de análisis de la interactividad y construcción de sistemas de significado compartido creado por Coll, Colomina, Onrubia y Rochera, (1992) y, por otro, el Sistema de análisis de la interacción ideado por Sánchez, Rosales y Suárez (1999). El objetivo de este doble análisis es constatar las diferencias y semejanzas entre ambos Sistemas a la hora de analizar la práctica educativa. Para ello presentamos la forma de proceder de cada uno de los Sistemas de análisis y de forma detallada mostramos para cada caso los procedimientos seguidos para el análisis, las medidas empleadas y los resultados prototípicos que se obtuvieron. Los resultados de esta comparación nos muestran que aunque los objetivos de partida puedan ser los mismos existen claras diferencias entre ambas formas de proceder. Estas diferencias afectan tanto al qué es lo que se estudia de igual forma que al cómo se estudia. The paper adopts a double perspective to analyse an educational situation. Specifically, we have analysed the interactions of a 6th year Primary Education teacher with her students using, on the one hand, the Interactivity system of analysis and the construction of systems of shared meaning created by Coll, Colomina, Onrubia, and Rochera, (1992) and, on the other hand, the Interaction system of analysis devised by Sanchez, Rosales, and Suárez (1999). The aim of this double analysis is to study differences and similarities between the two Systems applied to educational practice. Thus we present the procedure followed in each system of analysis, measures employed, and the prototypical results obtained. The results of this comparison show to us that even though clear the basic aims might be the same, there are clear differences between the two procedures. These differences affect both what is studied and how it is studied.
    Infancia y Aprendizaje 01/2006; 29(1):65-90. · 0.40 Impact Factor
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    ABSTRACT: An optimized protocol for the development and discovery of polymorphic AFLP markers in tree species is described. The protocol was optimized for the production of fluorescently labeled PCR products and analysis using a capillary sequencer. This approach has been demonstrated to be efficient and reproducible for tree species with complex genomes. The most important modification was in the selective amplification step. Instead of using a traditional step down PCR, a fixed and higher annealing temperature was employed, improving the reproducibility and sensitivity of the protocol. The levels of polymorphisms detected with the optimized protocol on three woody species are in agreement with those previously reported in the literature for tree species.
    Tree Genetics & Genomes 8(4). · 2.40 Impact Factor
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    BMC proceedings 5(7).