Ectopic expression of Chrysanthemum CDM19 in Arabidopsis reveals a novel function in carpel development

BACKGROUND: APETALA3 (AP3) has significant roles in petal and stamen development in accordance with the classical ABC model. RESULTS: The AP3 homolog, CDM19, from Chrysanthemum morifolium cv. Jinba was cloned and sequenced. Sequence and phylogenetic analyses revealed that CDM19 is of DEF/AP3 lineage possessing the characteristic MIKC-type II structure. Expression analysis showed that CDM19 was transcribed in petals and stamens of ray and disc florets with weak expression in the carpels. Ectopic expression of CDM19 in Arabidopsis wild-type background altered carpel development resulting in multi-carpel siliques. CDM19 could only partially rescue the Arabidopsis ap3­­3 mutant. CONCLUSIONS: Our results suggest that CDM19 may partially be involved in petal and stamen development in addition to having novel function in carpel development.

Actin filaments mediated root growth inhibition by changing their distribution under UV-B and hydrogen peroxide exposure in Arabidopsis

BACKGROUND: UV-B signaling in plants is mediated by UVR8, which interacts with transcriptional factors to induce root morphogenesis. However, research on the downstream molecules of UVR8 signaling in roots is still scarce. As a wide range of functional cytoskeletons, how actin filaments respond to UV-B-induced root morphogenesis has not been reported. The aim of this study was to investigate the effect of actin filaments on root morphogenesis under UV-B and hydrogen peroxide exposure in Arabidopsis. RESULTS: A Lifeact-Venus fusion protein was used to stain actin filaments in Arabidopsis. The results showed that UV-B inhibited hypocotyl and root elongation and caused an increase in H2O2 content only in the root but not in the hypocotyl. Additionally, the actin filaments in hypocotyls diffused under UV-B exposure but were gathered in a bundle under the control conditions in either Lifeact-Venus or uvr8 plants. Exogenous H2O2 inhibited root elongation in a dose-dependent manner. The actin filaments changed their distribution from filamentous to punctate in the root tips and mature regions at a lower concentration of H2O2 but aggregated into thick bundles with an abnormal orientation at H2O2 concentrations up to 2 mM. In the root elongation zone, the actin filament arrangement changed from lateral to longitudinal after exposure to H2O2. Actin filaments in the root tip and elongation zone were depolymerized into puncta under UV-B exposure, which showed the same tendency as the low-concentration treatments. The actin filaments were hardly filamentous in the maturation zone. The dynamics of actin filaments in the uvr8 group under UV-B exposure were close to those of the control group. CONCLUSIONS: The results indicate that UV-B inhibited Arabidopsis hypocotyl elongation by reorganizing actin filaments from bundles to a loose arrangement, which was not related to H2O2. UV-B disrupted the dynamics of actin filaments by changing the H2O2 level in Arabidopsis roots. All these results provide an experimental basis for investigating the interaction of UV-B signaling with the cytoskeleton.

impacts of TRR14-overexpression on arabidopsis thaliana growth and photosynthetic parameters

Background: TRR14 protein is a small protein, a member of a multigene family in Arabidopsis which was found as the first protein during screening seedlings for their resistant to the trehalose sugar

Objectives: A number of TRR14-overexpressing plants were subjected to the characterization in the present research, among which, the associated morphological features and changes accompany growth pattern and photosynthesis related parameters

Materials and Methods: TRR14 gene was isolated from Arabidopsis Thaliana and cloned into the pBin-35S vector. Recombinant vector was transferred to the Arabidopsis [Col-0] via Agrobacterium tumefaciens using the Floral Dipping method. Seeds from the TRR14 overexpressed [TRR14] and the Col-0 wild-type [WT] plants were shown on soil under long day conditions. Several measurements were then performed including determination of the fresh and dry weights, leaf area, chlorophyll a and b [Chl a and Chl b] content, Chl a/b ratio, total chlorophyll and carotenoids content, soluble and insoluble sugars content, total and soluble protein content, the Hill reaction rate, chlorophyll fluorescence, as well as photorespiration rate. Meanwhile, the chloroplastic proteins were investigated by SDS-PAGE analysis

Results: TRR14 plants showed a significant increase in fresh and dry weights, leaf area, and total and soluble protein content along with a significant decrease in the insoluble sugar contents was observed in comparison to the WT plants. Chl a, Chl b, total chlorophyll content, Chl a/b ratio, carotenoids content, Hill reaction rate, and chlorophyll fluorescence didn't show a significant difference between TRR14 and WT plants. The SDS-PAGE gel electrophoresis of the chloroplastic proteins showed a thick band with a molecular mass of 25 kDa in TRR14-overexpressed plants, compared to the WT plants. Remarkably, photorespiration rate was decreased in TRR14 plants compared to WT plants

Conclusion: The increased biomass of TRR14 transformed plants might be due to its ability in reducing photorespiration through concentrating CO2 in the leaf's intercellular spaces

Religión y salud: la intervención pública de agentes religiosos católicos formados en bioética en el debate parlamentario sobre la muerte digna en la Argentina / Religion and health: the public intervention of Catholic religious agents trained in bioethics in the parliamentary debate on death with dignity in Argentina

Desde una perspectiva sociológica, este trabajo aborda una de las aristas de la intervención pública de ciertos sectores del catolicismo en la elaboración y sanción de leyes de salud. En particular se hace foco en el debate en comisiones parlamentarias sobre la llamada ley de "muerte digna" (Ley 26742) en el cual se convocó a un grupo de expertos en bioética para asesorar a los senadores sobre los alcances y límites de la ley. La mayoría de los expertos invitados pregonan la perspectiva de la bioética personalista, un desarrollo teológico de la bioética del catolicismo contemporáneo. En el debate no participaron representantes de otros credos consolidando la ampliamente estudiada imbricación entre el catolicismo y lo político en Argentina.

This paper discusses from a sociological perspective one of Catholicism's fronts of public intervention in the development and enactment of health legislation. In particular we analyze the debate in parliamentary committees on the so-called "death with dignity" law (No. 26742), for which a group of bioethics experts was convened to counsel senators regarding the scope and limits of the law. The majority of the invited experts advocated a personalist bioethics perspective, which is a theological bioethics development of contemporary Catholicism. In the debate no representatives of other faiths were present, reinforcing the widely studied overlap between Catholicism and politics in Argentina.

Avaliação dos estudantes de enfermagem sobre a aprendizagem com a simulação clínica / Evaluación de los estudiantes de enfermería sobre el aprendizaje con la simulación clínica / Evaluation of nursing students about learning with clinical simulation

RESUMO Objetivo: descrever as contribuições da simulação clínica para aprendizagem de atributos cognitivos e procedimentais, por meio do debriefing, na perspectiva dos estudantes de enfermagem. Método: estudo descritivo exploratório. Participaram 20 estudantes de Graduação em Enfermagem de uma universidade do interior paulista. Na coleta de dados, realizada na etapa do debriefing, foi registrada a percepção do aluno sobre a simulação, aspectos positivos e o que poderia ser feito de forma diferente. Os relatos foram agrupados em categorias temáticas centrais, segundo referencial de análise de conteúdo de Bardin (2011), analisadas por meio de estatística descritiva. Resultados: identificada valorização da aprendizagem ativa, crítica e reflexiva (47,5%) em decorrência da aproximação à realidade assistencial (20,3%), manifestação dos sentimentos vivenciados durante a simulação (16,9%) e composição do cenário (15,3%). Conclusão: a simulação clínica seguida do debriefing favorece a compreensão da relação entre ação e resultados alcançados na aprendizagem. .

RESUMEN Objetivo: describir las contribuciones de simulación clínica para aprender atributos cognitivos y de procedimiento, a través de debriefing, desde la perspectiva de los estudiantes de enfermería. Método: estudio exploratorio descriptivo. 20 estudiantes participaron en el Pregrado en Enfermería de una universidad de São Paulo. Durante la recolección de datos, que se aplicó durante el debriefing, fue grabado en la percepción de los estudiantes de la simulación, los aspectos positivos y lo que podría hacerse de otra manera. Los informes de los estudiantes se agrupan de acuerdo a los temas centrales, según el referencial de análisis de contenido de Bardin (2011) y analizados mediante estadística descriptiva. Resultados: identificado la mejora de aprendizaje activo, crítico y reflexivo (47,5%) debido a la aproximación a la realidad en la atención de enfermería (20,3%), un resultado de la composición del escenario (16,9%), lo que favorece el desarrollo de sentimientos experimentados durante la simulación (15,3%). Conclusión: la simulación clínica seguida de debriefing favorece la comprensión de la relación entre la acción y los resultados obtenidos en el aprendizaje. .

ABSTRACT Objective: to describe the contributions of clinical simulation for learning cognitive and procedural attributes through debriefi ng, from the perspective of nursing students. Method: descriptive exploratory study. Twenty nursing undergraduate students from a university in the interior of the state of São Paulo participated in this study. Data collection was performed at the debriefi ng stage. Student’s perceptions about the simulation, positive aspects and what they could have done differently were registered. The students’ statements were grouped according to the central themes and the framework of Bardin’s content analysis (2011) and were analyzed using descriptive statistics. Results: enhancement of active, critical and refl ective learning (47.5%) was identifi ed due to the closeness to reality in nursing care (20.3%), manifestation of feelings experienced during the simulation (15.3%) and composition of the scenario (15.3%). Conclusion: the clinical simulation followed by debriefi ng promotes the understanding of the link between action and achievements in learning. .

Phenotypic plasticity and ecotypic variations in growth and flowering time of Arabidopsis thaliana (L.) under different light and temperature conditions.

Four ecotypes of A. thaliana (L.) (Ct-1, Pf-0, Old-1 and Per-1) from low to high latitudes were grown under different light (300 mmol photon m-2s-1 and 150 mmol photon m-2s-1) and temperature (22 and 14 ºC) conditions to investigate their effects on phenotypic plasticity and ecotypic variations in plant growth and first flowering time. The results suggest that in A. thaliana low temperature decreases both phenotypic plasticity and ecotypic variations in first flowering time and total dry matter at final harvest under different light intensities. Relative growth rate is the most stable parameter of A. thaliana that is hardly affected by ecotype (no effect), light (no effect) or temperature (small effect) and this may one of the reason why A. thaliana is widely distributed on earth as a result of adaptations to different environments.

Effect of cryopreservation on the efficiency of exogenous gene, genetic transformation and expression level of Arabidopsis thaliana

Background: Cryopreservation refers to the storage of a living organism at ultra-low-temperature for long-term preservation of plant germplasm. The effect of cryopreservation on the efficiency of exogenous gene genetic transformation and expression level were studied herein. In this work, transgenic Arabidopsis thaliana were successfully conserved in vitro by cryopreservation methods. Results: The effects of osmotic stress due to cryoprotectants during pretreatment and of storage at -196ºC on the stability, the efficiency of genetic transformation and the expression level of exogenous gene were analyzed in Arabidopsis. The results showed that there had not any significant increasing in the efficiency of genetic transformation after cryopreservation, and our observation was not in agreement with earlier reports. Transgenic Arabidopsis lines over-expressing ATOST1 gene were used for the real-time PCR analysis, and the result indicated that the expression of the ATOST1 gene was up-regulated about 2.4-fold in the transgenic seedlings tissues retrieved from cryopreservation than those non-cryopreserved counterparts. Conclusions： Cryopreservation could improve the expression of exogenous gene, however, could not promote the genetic transformation obviously.

A phage display combined with DNA affinity magnetic system can be applied to a screening of DNA binding proteins, such as transcription factors / Un fago pantalla combinado con un sistema de afinidad magnético al ADN se puede aplicar al exámen de las proteínas de unión al ADN, tales como los factores de transcripción

Here we introduce a new approach for the screening of DNA binding proteins, using a phage library based on a phage display technique. In principal, a complementary DNA (cDNA) library based on the recombinant bacteriophage T7 expressing target proteins on its capsid (phage display) is constructed. These phage particles are hybridized with a biotinylated target DNA fragment which is immobilized on the surface of streptavidin paramagnetic particle (SA-PMP). The phage particles are released from the target DNA fragment by a nuclease treatment and the recovered phages are used to the next round of hybridization. These processes are repeated three times to amplify the target phages in the population. This simple method is faster, and more systemic than other current methods (e.g. yeast one hybrid system). As a proof of this principle, we tried to isolate transcription factors which specifically bind to the promoter region of the Arabidopsis thaliana AtGST11 gene. Two obtained candidates, RING zinc finger protein and AtHB6, showed DNA binding activity to the AtGST11 promoter region. We could validate that our new application of phage display is a superior method for isolation of DNA binding proteins with a broad range of potential applications.

The Ca2+ pump inhibitor, thapsigargin, inhibits root gravitropism in Arabidopsis thaliana

Thapsigargin, a specific inhibitor of most animal intracellular SERCA-type Ca2+ pumps present in the sarcoplasmic/endoplasmic reticulum, was originally isolated from the roots of the Mediterranean plant Thapsia gargancia L. Here, we demonstrate that this root-derived compound is capable of altering root gravitropism in Arabidopsis thaliana. Thapsigargin concentrations as low as 0.1 µM alter root gravitropism whereas under similar conditions cyclopiazonic acid does not. Furthermore, a fluorescently conjugated thapsigargin (BODIPY FL thapsigargin) suggests that target sites for thapsigargin are located in intracellular organelles in the root distal elongation zone and the root cap, regions known to regulate root gravitropism.