An anion conductance, the essential component of the hydroxyl-radical-induced Ion current in plant roots

IGOR POTTOSIN ALBERTO ISAAC ZEPEDA JAZO JAYACUMAR BOSE (2018, [Artículo])

Oxidative stress signaling is essential for plant adaptation to hostile environments. Previous studies revealed the essentiality of hydroxyl radicals (HO•)-induced activation of massive K+ efflux and a smaller Ca2+ influx as an important component of plant adaptation to a broad range of abiotic stresses. Such activation would modify membrane potential making it more negative. Contrary to these expectations, here, we provide experimental evidence that HO• induces a strong depolarization, from −130 to −70 mV, which could only be explained by a substantial HO•-induced efflux of intracellular anions. Application of Gd3+ and NPPB, non-specific blockers of cation and anion conductance, respectively, reduced HO• induced ion fluxes instantaneously, implying a direct block of the dual conductance. The selectivity of an early instantaneous HO•-induced whole cell current fluctuated from more anionic to more cationic and vice versa, developing a higher cation selectivity at later times. The parallel electroneutral efflux of K+ and anions should underlie a substantial leak of the cellular electrolyte, which may affect the cell’s turgor and metabolic status. The physiological implications of these findings are discussed in the context of cell fate determination, and ROS and cytosolic K+ signaling

BIOQUÍMICA Anions Membrane potentials (Electrophysiology) Patch-clamp techniques (Electrophysiology) Oxidative stress Anion conductance Electrolyte leakage Hydroxyl radical

A Novel Technique for Classifying Bird Damage to Rapeseed Plants Based on a Deep Learning Algorithm.

Ali Mirzazadeh Afshin Azizi Yousef Abbaspour_Gilandeh José Luis Hernández-Hernández Mario Hernández Hernández Iván Gallardo Bernal (2021, [Artículo])

Estimation of crop damage plays a vital role in the management of fields in the agricultura sector. An accurate measure of it provides key guidance to support agricultural decision-making systems. The objective of the study was to propose a novel technique for classifying damaged crops based on a state-of-the-art deep learning algorithm. To this end, a dataset of rapeseed field images was gathered from the field after birds¿ attacks. The dataset consisted of three classes including undamaged, partially damaged, and fully damaged crops. Vgg16 and Res-Net50 as pre-trained deep convolutional neural networks were used to classify these classes. The overall classification accuracy reached 93.7% and 98.2% for the Vgg16 and the ResNet50 algorithms, respectively. The results indicated that a deep neural network has a high ability in distinguishing and categorizing different image-based datasets of rapeseed. The findings also revealed a great potential of Deep learning-based models to classify other damaged crops.

rapeseed classification damaged crops deep neural networks INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS

EVALUACIÓN DE LA ACTIVIDAD Y EXPRESIÓN GÉNICA DE ENZIMAS ANTIOXIDANTES (SOD, GPX, GST, GR y CAT) COMO BIOMARCADORES DE EXPOSICIÓN A FTALATOS EN CULTIVO CELULAR

Elizabeth Brassea Pérez (2023, [Tesis de doctorado])

"El plastificante bis(2-etilhexilo) ftalato (DEHP) altera el equilibrio entre la producción de especies reactivas de oxígeno y las defensas antioxidantes. A pesar de la información disponible sobre los efectos tóxicos del DEHP en organismos modelo, la respuesta celular al DEHP en especies naturalmente adaptadas para tolerar el estrés oxidativo aún no se ha explorado. Los mamíferos marinos están naturalmente adaptados para hacer frente al estrés oxidativo derivado de la isquemia/reperfusión inducida por el buceo. El objetivo de este estudio fue comparar los cambios en los indicadores de estrés oxidativo asociados al DEHP en células de músculo esquelético de humanos (Homo sapiens sapiens) y lobos marinos de California (Zalophus californianus). Se recolectaron muestras de músculo abdominal de mujeres sanas sometidas a cesárea programada, tras obtener su consentimiento informado. Las muestras de músculo de lobo marino se obtuvieron de crías encontradas recientemente muertas en la colonia de Los Islotes, Golfo de California. Las células de músculo esquelético se aislaron y cultivaron en condiciones estándar. Las células se dividieron en dos grupos. Un grupo fue expuesto a DEHP (1 mM) durante 13 días (n=25; exposición), el otro grupo se mantuvo bajo condiciones control, es decir sin DEHP añadido (n=25; control). Se midió la producción de radical superóxido (O2•-), el daño oxidativo, la actividad de enzimas antioxidantes y la expresión génica mediante métodos espectrofotométricos y RT-qPCR. En células expuestas al DEHP la producción de O2•- y la actividad de superóxido dismutasa (SOD) fueron mayores que en las células bajo condiciones control para ambas especies. La actividad de glutatión S-transferasa (GST) y los niveles de carbonilos proteicos (PC) aumentaron significativamente en las células humanas expuestas a DEHP, y no significativamente en las células de lobo marino. Por el contrario, las actividades de glutatión peroxidasa (GPx) y catalasa (CAT) aumentaron significativamente en las células de lobo marino, pero no en las de humano expuestas a DEHP. Se observó una expresión diferencial de los genes implicados en el metabolismo redox entre las células control y expuestas a DEHP y entre especies. Los patrones de expresión de 26 y 19 genes fueron significativamente diferentes en las células humanas y de lobo marino, respectivamente, después de la exposición a DEHP. En las células humanas, la expresión de la GST1 microsomal y la GST (κ, μ, θ, ω y ᴢ) fue mayor,

"The plasticizer bis (2-ethylhexyl) phthalate (DEHP) dysregulates the balance between reactive oxygen species production and antioxidant defenses. Despite the information available on DEHP’s hazardous effects in model species, the cellular response to DEHP in organisms naturally adapted to tolerate oxidative stress remains unexplored. Marine mammals are naturally adapted to cope with oxidative stress derived from diving-induced ischemia/reperfusion. The objective of this study was to compare changes in oxidative stress indicators induced by DEHP in human (Homo sapiens sapiens) and California sea lion (Zalophus californianus) skeletal muscle cells. Abdominal muscle samples were collected from healthy women undergoing planned cesarean surgery at full term after obtaining informed consent. Sea lion muscle samples were obtained from recently deceased pups at Los Islotes rookery, Gulf of California. Skeletal muscle cells were isolated and cultured under standard conditions. Cells were divided into two groups. One group was exposed to 1 mM DEHP for 13 days (n=25; treatment), and the other served as a control (n=25; no DEHP). Superoxide radical (O2•-) production, oxidative damage, antioxidant enzyme activities and gene expression were measured using spectrophotometric methods and RT-qPCR. DEHP exposure increased O2•- production and superoxide dismutase (SOD) activity in both species. While the activity of glutathione S-transferase (GST) and protein carbonyls (PC) levels significantly increased in human cells, these indicators showed a non-significant elevation in sea lion cells. In contrast, glutathione peroxidase (GPx) and catalase (CAT) activities increased significantly in sea lion but not in human cultures exposed to DEHP. Genes involved in redox metabolism showed differential expression between treatments and species. DEHP exposure led to widespread modifications in gene expression patterns, with 26 and 19 differentially expressed genes in human and sea lion cells, respectively. In human cells, DEHP increased GST1 and GST (κ, μ, θ, ω, and ᴢ), while suppressing 8-oxoguanine DNA glycosylase (OGG1), CAT, GR, and nuclear factor erythroid 2-related factor 2 (NRF2) expression, suggesting increased oxidative stress and phase two detoxification processes. In contrast, DEHP increased OGG1, NRF2, GPx2 and SOD3 expression, suggesting that DEHP activates antioxidant defenses in sea lion cells, potentially contributing to maintain redox homeostasis and avoid oxidative...

Contaminantes emergentes, enzimas antioxidantes, estrés oxidativo, mamíferos, Una Salud Antioxidant enzymes, emerging pollutants, mammals, One Health, oxidative stress BIOLOGÍA Y QUÍMICA QUÍMICA BIOQUÍMICA ENZIMOLOGIA ENZIMOLOGIA