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Bassinosteroids (BRs) can induce plant defence responses and promote plant growth. In this work, we evaluated the effect of a natural (EP24) and a synthetic (BB16) brassinosteroid on strawberry (Fragaria vesca ) plants exposed to saline stress. Treated plants showed higher shoot dry weight and root growth compared to untreated control plants. In BR-treated plants, crown diameters increased 66% and 40%, leaf area 148% and 112%, relative water content in leaves 84% and 61%, and SPAD values 24% and 26%, in response to BB16 and EP24, respectively. A marked stomatal closure, increased leaflet lignification, and a decrease in cortex thickness, root diameter and stele radius were also observed in treated plants. Treatments also reduces stress-induced damage, as plants showed a 34% decrease in malondialdehyde content and a lower proline content compared to control plants. A 22% and 15% increase in ascorbate peroxidase and total phenolic compound activities was observed in response to BB16, and a 24% increase in total flavonoid compound in response to both BRs, under stress conditions. These results allow us to propose the use of BRs as an environmentally safe crop management strategy to overcome salinity situations that severely affect crop yield.

Abiotic stress has been shown to induce the formation of reactive oxygen species (ROS) in plant cells. When the level of ROS surpasses the capacity of the endogenous defence mechanism, oxidative stress status is reached, leading to plant damage and a drop in crop productivity. Under oxidative stress conditions, ROS can react with polyunsaturated fatty acids to form oxidized derivatives called phytoprostanes (PhytoPs) and phytofurans (PhytoFs), which are recognized as biomarkers of oxidative damage advance. Modern agriculture proposes the use of biostimulants as a sustainable strategy to alleviate the negative effects of oxidative stress on plants. This work evaluates the dose effect of natural antioxidant extract to mitigate the oxidative-stress deleterious effects in melon and sweet pepper exposed to thermal stress. The plants were sprayed with Ilex paraguariensis (IP) aqueous extract in three different concentrations before exposure to abiotic stress. PhytoP and PhytoF levels were determined in the leaves of melon and pepper plants. IP1 and IP2 were effective against oxidative stress in both plants, with IP1 being the most protective one. IP1 decreased the levels of PhytoPs and PhytoFs by roughly 44% in both melon plants and pepper plants. The yield, with IP1, increased by 57 and 39% in stressed melon and pepper plants, respectively. IP3 foliar application in melon plants induced a pro-oxidant effect rather than the expected mitigating action. However, in sweet pepper plants, IP3 decreased the oxidative stress progress and increased the fruit yield., (© 2023 Scandinavian Plant Physiology Society.)

Quantification of endogenous hormones in plants is essential to understand their growth, development and response to biotic and abiotic stresses. However, it is challenging to develop high-throughput sample treatments from complex plant tissues containing low amounts of structurally unrelated and labile phytohormones while delivering clean and analyte-enriched extracts. In this paper we propose the use of supramolecular solvents (SUPRASs) made up or inverted hexagonal nanostructures of alkanols to address this challenge. The strategy was applied, as a proof of concept, to the quantification of stress-related phytohormones belonging to different categories (abscisic acid, salicylic acid, jasmonic acid, methyl jasmonate and 3-indoleacetic acid) in melon and pepper leaves. Sample treatment consisted in a single extraction-cleanup step involving the use of a low volume of SUPRAS (244 μL), the stirring (5 min) and centrifugation (15 min) of the sample at room temperature, and the direct analysis of the extract by liquid chromatography tandem mass spectrometry (LC-MS/MS). This high-throughput sample treatment method delivered excellent results for the target phytohormones regarding absolute recoveries (80-92%), method quantification limits (0.05-2 ng g -1 ), reproducibility (1-7%) and matrix effects (+13 to -31%), in both melon and pepper leaves, compared to reported methods based on repetitive solvent extraction, purification and solvent evaporation steps. The method was successfully applied to determine target hormones in melon and pepper plants for the evaluation of the effect of thermal stress. It was found that their concentration increased in the ranges 1.2-1.9 and 1.3-3.8 times in melon and pepper leaves, respectively, compared with control samples., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In recent years, nanopores have emerged as exceptionally promising single-molecule sensors due to their ability to detect biomolecules at subfemtomole levels in a label-free manner. Development of a high-throughput nanopore-based biosensor requires multiplexing of nanopore measurements. Electrical detection, however, poses a challenge, as each nanopore circuit must be electrically independent, which requires complex nanofluidics and embedded electrodes. Here, we present an optical method for simultaneous measurements of the ionic current across an array of solid-state nanopores, requiring no additional fabrication steps. Proof-of-principle experiments are conducted that show simultaneous optical detection and characterization of ssDNA and dsDNA using an array of pores. Through a comparison with electrical measurements, we show that optical measurements are capable of accessing equivalent transmembrane current information.

Introduction: The clinical profile as well as the therapeutic and diagnostic strategies for patients with pulmonary embolism, describes clinical practice in the approach of the disease. Such information, scarce in national studies, enables a better understanding of pulmonary embolism., Methods: A multicenter trial included 727 patients with pulmonary embolism who were admitted in emergency or intensive care unit. Diagnostic criteria for inclusion were: 1. Visibility of thrombus in the pulmonary artery at pulmonary arteriography, helical computer tomography, magnetic resonance or echocardiogram. 2. High probability at pulmonary scintigraphy. 3. Venous duplex-scan with thrombus and clinical manifestations of pulmonary embolism. Clinical and complementary exams were analyzed., Results: Mean age was 68 years, 42% were male. Most prevalent risk factors were: age>40 years, bed rest and neoplasm. More frequent signs and symptoms were: dyspnea, tachypnea, sinus tachycardia, and chest pain. Changes were observed at electrocardiogram in 30%, at chest X-ray in 45%, at venous duplex-scan in 67%, at transthoracic echocardiogram in 37%. . D-dimer, troponin I and CKMB were positive in, respectively, 93, 9 and 8%. Most frequently used methods to confirm diagnosis were helical computer tomography and non-fractioned heparin was the treatment most used. In-hospital mortality was 19.5%., Conclusions: It was observed that age>40 years, prolonged rest and neoplasms were the most prevalent risk factors and dyspnea and tachypnea were the more frequent clinical manifestations. Helical computer tomography was the most often used method to confirm diagnosis and non-fractioned heparin was the main form of treatment.