A root specific induction of carotenoid biosynthesis contributes to ABA production upon salt stress in arabidopsis

Abscisic acid (ABA) is a hormone that plays a vital role in mediating abiotic stress responses in plants. Salt exposure induces the synthesis of ABA through the cleavage of carotenoid precursors (xanthophylls), which are found at very low levels in roots. Here we show that de novo ABA biosynthesis in salt-treated Arabidopsis thaliana roots involves an organ-specific induction of the carotenoid biosynthetic pathway. Upregulation of the genes encoding phytoene synthase (PSY) and other enzymes of the pathway producing ABA precursors was observed in roots but not in shoots after salt exposure. A pharmacological block of the carotenoid pathway substantially reduced ABA levels in stressed roots, confirming that an increase in carotenoid accumulation contributes to fuel hormone production after salt exposure. Treatment with exogenous ABA was also found to upregulate PSY expression only in roots, suggesting an organ-specific feedback regulation of the carotenoid pathway by ABA. Taken together, our results show that the presence of high concentrations of salt in the growth medium rapidly triggers a root-specific activation of the carotenoid pathway, probably to ensure a proper supply of ABA precursors required for a sustained production of the hormone

Presencia de Aphis arbuti Ferrari y Wahlgreniella nervata (Gillete) (Hemiptera, Aphididae) en los madroños de la Comunidad de Madrid y estudio de la fumagina asociada.

Determinación de los pulgones asociados al madroño y su relación con los hongos desarrollados sobre la melaza

Global DNA methylation and transcriptional analyses of human ESC-derived cardiomyocytes.

With defined culture protocol, human embryonic stem cells (hESCs) are able to generate cardiomyocytes in vitro, therefore providing a great model for human heart development, and holding great potential for cardiac disease therapies. In this study, we successfully generated a highly pure population of human cardiomyocytes (hCMs) (>95% cTnT(+)) from hESC line, which enabled us to identify and characterize an hCM-specific signature, at both the gene expression and DNA methylation levels. Gene functional association network and gene-disease network analyses of these hCM-enriched genes provide new insights into the mechanisms of hCM transcriptional regulation, and stand as an informative and rich resource for investigating cardiac gene functions and disease mechanisms. Moreover, we show that cardiac-structural genes and cardiac-transcription factors have distinct epigenetic mechanisms to regulate their gene expression, providing a better understanding of how the epigenetic machinery coordinates to regulate gene expression in different cell types

Propiedades insecticidas del polvo de Laurelia sempervirens L. para el control de Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

Sitophilus zeamais is a key pest of stored cereals. The insecticidal properties of Laurelia semper v irens powder against S. zeamais were assessed in laboratory. The variable evaluated were morta lity of adult insects by contact and fumigant toxicity, mortality of immature insects by contact toxicity, residual effect of powder stored under environmental or refrigerated conditions, adult insect em ergence (F1), repellency and weight reduction and ger mination of maize. The concentrations evaluated were 0, 0.25, 0.5, 1.0, 2.0 and 4.0% and the experimental design was completely randomly. In contact toxicity bioassay all treatments showed mortality over 90% while fumi gant activity did not exceed 40%. The F1 only was registered in treatment of 0.25% and control showing all other treatments 0%. In immature control bioassay all treatments exhibited statistical differences with control. The storage of powder under refrigerated cond itions not improved the resid ual effect. All concentrations of powder assessed showed repellence. Germination and grain weight loss of maize seeds not showed significant differences with control. We concluded that L. sempervirens has promissory perspectives to stored grain pests contr ol

Tomato fruit carotenoid biosynthesis is adjusted to actual ripening progression by a light-dependent mechanism

Carotenoids are isoprenoid compounds that are essential for plants to protect the photosynthetic apparatus against excess light. They also function as health-promoting natural pigments that provide colors to ripe fruit, promoting seed dispersal by animals. Work in Arabidopsis thaliana unveiled that transcription factors of the phytochrome-interacting factor (PIF) family regulate carotenoid gene expression in response to environmental signals (i.e. light and temperature), including those created when sunlight reflects from or passes though nearby vegetation or canopy (referred to as shade). Here we show that PIFs use a virtually identical mechanism to modulate carotenoid biosynthesis during fruit ripening in tomato (Solanum lycopersicum). However, instead of integrating environmental information, PIF-mediated signaling pathways appear to fulfill a completely new function in the fruit. As tomatoes ripen, they turn from green to red due to chlorophyll breakdown and carotenoid accumulation. When sunlight passes through the flesh of green fruit, a self-shading effect within the tissue maintains high levels of PIFs that directly repress the master gene of the fruit carotenoid pathway, preventing undue production of carotenoids. This effect is attenuated as chlorophyll degrades, causing degradation of PIF proteins and boosting carotenoid biosynthesis as ripening progresses. Thus, shade signaling components may have been co-opted in tomato fruit to provide information on the actual stage of ripening (based on the pigment profile of the fruit at each moment) and thus finely coordinate fruit color change. We show how this mechanism may be manipulated to obtain carotenoid-enriched fruits.Peer ReviewedPostprint (published version

Making extra room for carotenoids in plant cells: new opportunities for biofortification

[EN] Plant carotenoids are essential for photosynthesis and photoprotection and provide colors in the yellow to red range to non-photosynthetic organs such as petals and ripe fruits. They are also the precursors of biologically active molecules not only in plants (including hormones and retrograde signals) but also in animals (including retinoids such as vitamin A). A carotenoid-rich diet has been associated with improved health and cognitive capacity in humans, whereas the use of carotenoids as natural pigments is widespread in the agrofood and cosmetic industries. The nutritional and economic relevance of carotenoids has spurred a large number of biotechnological strategies to enrich plant tissues with carotenoids. Most of such approaches to alter carotenoid contents in plants have been focused on manipulating their biosynthesis or degradation, whereas improving carotenoid sink capacity in plant tissues has received much less attention. Our knowledge on the molecular mechanisms influencing carotenoid storage in plants has substantially grown in the last years, opening new opportunities for carotenoid biofortification. Here we will review these advances with a particular focus on those creating extra room for carotenoids in plant cells either by promoting the differentiation of carotenoid-sequestering structures within plastids or by transferring carotenoid production to the cytosol.We greatly thank Carmen and Pilar Torres-Montilla for their collaboration and help in the design and execution of the figures. We also thank Luca Morelli and BioRender.com for some of the images. Work in our lab is funded by Spanish grants BIO2017-84041-P and PID2020-115810GB-I00 from the Agencia Estatal de Investigacion (AEI) and 202040E299 from Consejo Superior de Investigaciones Cientificas (CSIC) to MRC. STM was supported by PhD fellowship FPU16/04054 from the Spanish Ministerio de Educacion y CulturaTorres-Montilla, S.; Rodriguez-Concepcion, M. (2021). Making extra room for carotenoids in plant cells: new opportunities for biofortification. Progress in Lipid Research. 84:1-9. https://doi.org/10.1016/j.plipres.2021.101128S198

LAS AGUAS DEL MAR EN EDIPO REY Y EDIPO EN COLONO DE SÓFOCLES

As agitadas águas do mar retornam na tragédia Édipo Rei para configurar um cenário de doença, destruição e morte. O mar no Édipo em Colono, juntamente com os mananciais e a terra, configura um ‘espaço sagrado’ intemporal, localizado no santuário de Posídon em Colono (Atenas), temenos onde descansará Édip

Crecimiento del Cangrejo de Tierra Cardisoma Guanhumi en Puerto Rico

     The land crabs’ integument release process during molting represents a moment of vulnerability due to the desiccation risk and the lack of water availability for the molting.  The aim of this study is to ascertain Cardisoma guanhumi growth increase.  A marking-recapture study was conducted to estimate crab growth.  The study was carried out in six Puerto Rico locations.  It was found that growth increment is 8.7%, which is larger than previously reported; this increment varies among study sites.  Forests with higher vegetation coverage and lower edge density favor a larger growth increment. Crab´s habitat conservation is essential for the species´ survival.     Para los cangrejos terrestres, el proceso de liberación del integumento en el proceso de muda representa un momento de vulnerabilidad debido al riesgo de desecación y la disponibilidad de agua para el proceso de muda.  El objetivo de este estudio es determinar el incremento en crecimiento del cangrejo de tierra Cardisoma guanhumi.  Se realizó un estudio de marca-recaptura para estimar el crecimiento de los cangrejos.  El estudio se realizó en seis localidades en Puerto Rico.  Encontramos que el incremento en crecimiento es de 8.7% y que hay una diferencia entre los lugares de estudio.  Este incremento es mayor que lo reportado anteriormente.  La diferencia entre los lugares de estudio se debe a diferencias en la estructura de los bosques.  Los bosques con mayor cobertura vegetal y menos densidad de borde favorecen un incremento en crecimiento.  La conservación del hábitat del cangrejo es esencial para la sobrevivencia de esta especie

La Argumentatio en el tratado Sobre la tisana de Galeno

The role of Argumentatio in the Perì ptisánēs is studied in the present paper,considering basically Galen’s logical and rhetorical procedures in order to conforman exact example of dietetic lógos.http://dx.doi.org/10.14195/2183-1718_66_8Se analiza el papel de la “argumentación” en el tratado Perìptisánēs, teniendo en cuenta los procedimientos lógico‑retóricos que Galeno utiliza para construir su obra, un ejemplo perfecto de lógos dietético.http://dx.doi.org/10.14195/2183-1718_66_

Mechanism of action of 4-phenoxyphenoxyethyl thiocyanate (WC-9) against Trypanosoma cruzi, the causative agent of Chagas' disease

We investigated the molecular basis of the activity of 4-phenoxyphenoxyethyl thiocyanate (WC-9) against Trypanosoma cruzi, the etiological agent of Chagas' disease. We found that growth inhibition of T. cruzi epimastigotes induced by this compound was associated with a reduction in the content of the parasite's endogenous sterols due to a specific blockade of their de novo synthesis at the level of squalene synthase.Fil:Rodriguez, J.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina