Insights into oxidized lipid modification in barley roots as an adaptation mechanism to salinity stress

Lipidomics is an emerging technology, which aims at the global characterization and quantification of lipids within biological matrices including biofluids, cells, whole organs and tissues. The changes in individual lipid molecular species in stress treated plant species and different cultivars can indicate the functions of genes affecting lipid metabolism or lipid signaling. Mass spectrometry–based lipid profiling has been used to track the changes of lipid levels and related metabolites in response to salinity stress. We have developed a comprehensive lipidomics platform for the identification and direct qualification and/or quantification of individual lipid species, including oxidized lipids, which enables a more systematic investigation of peroxidation of individual lipid species in barley roots under salinity stress. This new lipidomics approach has improved with an advantage of analyzing the composition of acyl chains at the molecular level, which facilitates to profile precisely the 18:3-containing diacyl-glycerophosphates and allowed individual comparison of lipids across varieties. Our findings revealed a general decrease in most of the galactolipids in plastid membranes, and an increase of glycerophospholipids and acylated steryl glycosides, which indicate that plastidial and extraplastidial membranes in barley roots ubiquitously tend to form a hexagonal II (HII) phase under salinity stress. In addition, salt-tolerant and salt-sensitive cultivars showed contrasting changes in the levels of oxidized membrane lipids. These results support the hypothesis that salt-induced oxidative damage to membrane lipids can be used as an indication of salt stress tolerance in barley

A high-resolution HPLC-QqTOF platform using parallel reaction monitoring for in-depth lipid discovery and rapid profiling

Here, we developed a robust lipidomics workflow merging both targeted and untargeted approaches on a single liquid chromatography coupled to quadrupole-time of flight (LC-QqTOF) mass spectrometry platform with parallel reaction monitoring (PRM). PRM assays integrate both untargeted profiling from MS1 scans and targeted profiling obtained from MS/MS data. This workflow enabled the discovery of more than 2300 unidentified features and identification of more than 600 lipid species from 23 lipid classes at the level of fatty acid/long chain base/sterol composition in a barley root extracts. We detected the presence of 142 glycosyl inositol phosphorylceramides (GIPC) with HN(Ac)-HA as the core structure of the polar head, 12 cardiolipins and 17 glucuronosyl diacylglycerols (GlcADG) which have been rarely reported previously for cereal crops. Using a scheduled algorithm with up to 100 precursors multiplexed per duty cycle, the PRM assay was able to achieve a rapid profiling of 291 species based on MS/MS data by a single injection. We used this novel approach to demonstrate the applicability and efficiency of the workflow to study salt stress induced changes in the barley root lipidome. Results show that 221 targeted lipids and 888 unknown features were found to have changed significantly in response to salt stress. This combined targeted and untargeted single workflow approach provides novel applications of lipidomics addressing biological questions

Neuromarketing: qué sabe de ti, que los demás no

En este documento se describe la forma en la que el neuromarketing hace que la segmentación de género, sea una herramienta funcional para poder conocer al cliente y sus deseos. Se explorará el mercadeo desde sus inicios, mostrando cómo evoluciona hasta enfocarse en el cliente como su principal objetivo. Al llegar a este punto el mercadeo se encuentra con un nuevo aliado, la neurociencia, la cual le muestra que por medio de diversas técnicas tiene la capacidad de medir las reacciones de su consumidor, a los distintos estímulos que le envía para cautivarlo. En este proceso se dan a conocer las tecnologías más usadas por el neuromarketing para este fin; además se expondrá parte de la anatomía del consumidor con la que interactúa el mercadeo: sus sentidos y su cerebro. Posteriormente se explica cómo a través del entendimiento de las percepciones y comportamiento del cliente, puede beneficiarse el mercadeo en sus propósitos y su vez, satisfacer al mercado en lo que realmente quiere.This document describes the way in which neuromarketing makes of gender segmentation a functional tool for knowing the customers and their desires. Marketing will be explored from its origins, showing how it evolves to focus on the customer as its main objective. At this point, marketing meets neuroscience, a new ally who shows through many techniques, that has the ability to measure the consumers’ reactions to the different stimuli that marketing sends to captivate them. In this process, it will make known the technologies that neuromarketing uses the most for this purpose; it will also present the consumers’ anatomy, which the marketing interacts with the most: the senses and the brain. Subsequently, it will be explained how, with understanding clients’ perceptions and behavior, marketing gets to benefit its purposes and at the same time satisfy what the market’s really wants.Centro de Estudios Empresariales para la Perdurabilida

String amplitudes in arbitrary dimensions

We calculate gravitational dressed tachyon correlators in non critcal dimensions. The 2D gravity part of our theory is constrained to constant curvature. Then scaling dimensions of gravitational dressed vertex operators are equal to their bare conformal dimensions. Considering the model as d+2 dimensional critical string we calculate poles of generalized Shapiro-Virasoro amplitudes.Comment: 14 page

The PRK/Rubisco shunt strongly influences Arabidopsis seed metabolism and oil accumulation, affecting more than carbon recycling

The carbon efficiency of storage lipid biosynthesis from imported sucrose in green Brassicaceae seeds is proposed to be enhanced by the PRK/Rubisco shunt, in which ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) acts outside the context of the Calvin–Benson–Bassham cycle to recycle CO2 molecules released during fatty acid synthesis. This pathway utilizes metabolites generated by the nonoxidative steps of the pentose phosphate pathway. Photosynthesis provides energy for reactions such as the phosphorylation of ribulose 5-phosphate by phosphoribulokinase (PRK). Here, we show that loss of PRK in Arabidopsis thaliana (Arabidopsis) blocks photoautotrophic growth and is seedling-lethal. However, seeds containing prk embryos develop normally, allowing us to use genetics to assess the importance of the PRK/Rubisco shunt. Compared with nonmutant siblings, prk embryos produce one-third less lipids—a greater reduction than expected from simply blocking the proposed PRK/Rubisco shunt. However, developing prk seeds are also chlorotic and have elevated starch contents compared with their siblings, indicative of secondary effects. Overexpressing PRK did not increase embryo lipid content, but metabolite profiling suggested that Rubisco activity becomes limiting. Overall, our findings show that the PRK/Rubisco shunt is tightly integrated into the carbon metabolism of green Arabidopsis seeds, and that its manipulation affects seed glycolysis, starch metabolism, and photosynthesis.ISSN:1040-4651ISSN:1531-298XISSN:1532-298

Attacks by a piercing-sucking insect (Myzus persicae Sultzer) or a chewing insect (Leptinotarsa decemlineata Say) on potato plants (Solanum tuberosum L.) induce differential changes in volatile compound release and oxylipin synthesis

Plant defensive strategies bring into play blends of compounds dependent on the type of attacker and coming from different synthesis pathways. Interest in the field is mainly focused on volatile organic compounds (VOCs) and jasmonic acid (JA). By contrast, little is known about the oxidized polyunsaturated fatty acids (PUFAs), such as PUFA-hydroperoxides, PUFA-hydroxides, or PUFA-ketones. PUFA-hydroperoxides and their derivatives might be involved in stress response and show antimicrobial activities. Hydroperoxides are also precursors of JA and some volatile compounds. In this paper, the differential biochemical response of a plant against insects with distinct feeding behaviours is characterized not only in terms of VOC signature and JA profile but also in terms of their precursors synthesized through the lipoxygenase (LOX)-pathway at the early stage of the plant response. For this purpose, two leading pests of potato with distinct feeding behaviours were used: the Colorado Potato Beetle (Leptinotarsa decemlineata Say), a chewing herbivore, and the Green Peach Aphid (Myzus persicae Sulzer), a piercing-sucking insect. The volatile signatures identified clearly differ in function with the feeding behaviour of the attacker and the aphid, which causes the smaller damages, triggers the emission of a higher number of volatiles. In addition, 9-LOX products, which are usually associated with defence against pathogens, were exclusively activated by aphid attack. Furthermore, a correlation between volatiles and JA accumulation and the evolution of their precursors was determined. Finally, the role of the insect itself on the plant response after insect infestation was highlighted

Arabidopsis CPR5 Independently Regulates Seed Germination and Postgermination Arrest of Development through LOX Pathway and ABA Signaling

The phytohormone abscisic acid (ABA) and the lipoxygenases (LOXs) pathway play important roles in seed germination and seedling growth and development. Here, we reported on the functional characterization of Arabidopsis CPR5 in the ABA signaling and LOX pathways. The cpr5 mutant was hypersensitive to ABA in the seed germination, cotyledon greening and root growth, whereas transgenic plants overexpressing CPR5 were insensitive. Genetic analysis demonstrated that CPR5 gene may be located downstream of the ABI1 in the ABA signaling pathway. However, the cpr5 mutant showed an ABA independent drought-resistant phenotype. It was also found that the cpr5 mutant was hypersensitive to NDGA and NDGA treatment aggravated the ABA-induced delay in the seed germination and cotyledon greening. Taken together, these results suggest that the CPR5 plays a regulatory role in the regulation of seed germination and early seedling growth through ABA and LOX pathways independently