Plant sulfolipid. II. Mutant study and phosphate deficiency

Study with SQDG-deficient mutants showed that formation of the sulfonic acid precursor, UDP-sulfoquinovose, in higher plants is considered to be catalyzed by the orthologous plant proteins SQD1. The second required plant enzyme, SQD2, is highly similar to glycosyltransferases and it is proposed that this protein represents sulfolipid synthase. The results of recent works have shown that for the stable activity PS II needs the presence of SQDG and that it participates in PS II recovering through some mechanism dependent on light. Under phosphate-limiting conditions a decrease in the content of one acidic lipid (PG) was accompanied by an increase in the content of the other acidic lipid (SQDG), which resulted in the maintenance of a certain level of total acidic lipids of chloroplast membranes

Effect of aluminium on redox-homeostasis of common buckwheat (Fagopyrum esculentum)

Common buckwheat is a significant culture in Ukraine, whose importance for food security has increased in recent decades. An important biological feature of buckwheat is the ability of the crop to grow on poor and especially acidic soils. Common buckwheat was sown in Ukraine on the area of 125,000 ha in 2020, mainly in the central part of the country and in the soil-climatic zone Polesie in the north of the country. At the same time, the area under buckwheat cultivation has been steadily decreasing in the last decade, which is due to the low profitability of cultivation on mainly acidic soils. The research was conducted in the field conditions during 2012–2018 in Kiev region, as well as in laboratory conditions. ICP analysis and biochemical methods were used. Yield of buckwheat on light soils of low fertility depends largely on the level of acidity of the soil. On acidic sod-podzolic soils with loam substrate, the aluminum content of the layer is 20–40 cm higher, compared to a layer of 0–20 cm. This is probably one of the reasons why, when the concentration of aluminum in the soil profile is increased, the root system is located mainly in the upper layer of soil with a lower content of aluminum. In this case, the study of the mechanisms of resistance to the action of aluminum on acidic soils is an important component of the cost-effectiveness of crop production in the region. In acidic soils with pH < 5.0, phytotoxic aluminum (Al3+) rapidly inhibits root growth and afterwards negatively affects water and nutrient uptake in plants. Acquiring phytotoxic capacities, in this connection Al ions affect a wide range of cellular and molecular processes, with a consequent reduction in plant growth. In most plant species, reactive oxygen species (ROS) production can also be induced by Al toxicity leading to oxidative damage of biomolecules and biological membranes. We have detected an accumulation of Al ions in leaf tissues of treatment plants after 10 days of exposure. Tissues of F. esculentum roots contained 155.4% of control level of Al and tissues of F. esculentum leaves – 186.2% of control level of Al ions. Significant intensification of O2•– generation in roots and leaf tissues as a reaction to Al addition to nutrient solution was detected. Increase in antioxidant enzymes activities and non fixed products of lipids peroxidation was characterized as a biochemical defense reaction of F. esculentum over the 10 days of exposure to Al (50 μM). Thus, the results show that the action of 50 μM of Al ions activated antioxidant enzymes – SOD and CAT and decreased oxidative processes, thus promotes pro/antioxidant balance of common buckwheat. These mechanisms of redox homeostasis can be triggers of morphological changes in buckwheat plants, which lead to increased crop resistance when growing on acidic soils with high aluminum content. Thus, the resistance of culture to acid soils may be associated with the possibility of increased accumulation of aluminum in the plant’s tissues, as well as in changes in redox homeostasis with subsequent morphological changes, and primarily the formation of the root system in the top layer of soil with a reduced content of aluminum

Obesity remodels activity and transcriptional state of a lateral hypothalamic brake on feeding

The current obesity epidemic is a major worldwide health concern. Despite the consensus that the brain regulates energy homeostasis, the neural adaptations governing obesity are unknown. Using a combination of high-throughput single-cell RNA sequencing and longitudinal in vivo two-photon calcium imaging, we surveyed functional alterations of the lateral hypothalamic area (LHA) - a highly conserved brain region that orchestrates feeding - in a mouse model of obesity. The transcriptional profile of LHA glutamatergic neurons was affected by obesity, exhibiting changes indicative of altered neuronal activity. Encoding properties of individual LHA glutamatergic neurons were then tracked throughout obesity, revealing greatly attenuated reward responses.These data demonstrate how diet disrupts the function of an endogenous feeding suppression system to promote overeating and obesity

The Cycocel effect on flavonoids content and phenylalanine ammonia-lyase (PAL) activity in buckwheat (Fagopyrum esculentum Moench.) plants

Flavonoids are important secondary plant metabolites with many and diverse key functions that belong to largest class of substances produced by plants – phenylpropanoids. These substances are of interested among plant and animal biochemists, plant pathologists, geneticists and biotechnologists. Flavonoids rutin and anthocyanin as herbal compounds characterized by physiological activity of a wide action spectrum: antiulcer, vitamin, antioxidant, stabilizing, ultraviolet radiation protecting, antitumor, tannic, etc. Therefore much attention has been attracted to biosynthesis of flavonoids and methods of its regulation and controlling. We determined concentration (2%) of growth regulator Cycocel (chlormequat chloride, CCC) that significantly raised anthocyanin and rutin levels in buckwheat (Fagopyrum esculentum Moench.) plants. Thin-layer chromatography revealed an increase in total flavonoids content in leaves of test plants, which was: by 3.5 times for rutin and by 8 times for anthocyanin. The same concentration of CCC had induced phenylalanine ammonia-lyase activity by 2 times. Moreover, an increase in the flavonoids content correlated with enzyme activity induction. Thus, the growth regulator Cycocel is an activator of flavonoids metabolism. Treatment by CCC significantly increased content of secondary flavonoid metabolites and activity of phenylalanine ammonia-lyase – flavonoids biosynthesis regulatory enzyme

La Biblioteca-Archivo de la Escuela de Estudios Árabes, un servicio con proyección cultural y educativa

Sección especial para la "Home" de la Web de la Red de Bibliotecas y Archivos del CSIC para dar a conocer de manera visual y textual aspectos representativos de las bibliotecas y archivos que constituyen la Red CSICTener como sede la Casa morisca del Chapiz, monumento del siglo XVI cuyo origen remontan algunos especialistas al período nazarí, convierte a la Escuela de Estudios Árabes del CSIC en un instituto de investigación de indudable singularidad. Excepcionales son también el Albaicín, barrio en el que está enclavada, su entorno paisajístico y patrimonial, frente a la Alhambra y la propia ciudad de Granada en la que todos ellos se asientan. No hay mejores elementos para enmarcar las actividades científicas que en él se desarrollan: la historia de al-Andalus y de sus textos, la arqueología y la arquitectura Islámicas.N

Prediction of human population responses to toxic compounds by a collaborative competition

\u3cp\u3eThe ability to computationally predict the effects of toxic compounds on humans could help address the deficiencies of current chemical safety testing. Here, we report the results from a community-based DREAM challenge to predict toxicities of environmental compounds with potential adverse health effects for human populations. We measured the cytotoxicity of 156 compounds in 884 lymphoblastoid cell lines for which genotype and transcriptional data are available as part of the Tox21 1000 Genomes Project. The challenge participants developed algorithms to predict interindividual variability of toxic response from genomic profiles and population-level cytotoxicity data from structural attributes of the compounds. 179 submitted predictions were evaluated against an experimental data set to which participants were blinded. Individual cytotoxicity predictions were better than random, with modest correlations (Pearson's r < 0.28), consistent with complex trait genomic prediction. In contrast, predictions of population-level response to different compounds were higher (r < 0.66). The results highlight the possibility of predicting health risks associated with unknown compounds, although risk estimation accuracy remains suboptimal.\u3c/p\u3

Dietary Methyl Deficiency, microRNA Expression and Susceptibility to Liver Carcinogenesis

BACKGROUND/AIMS: Altered expression of microRNAs is frequently detected during tumor development; however, it has not been established if variations in the expression of specific microRNAs are associated with differences in the susceptibility to tumorigenesis. METHODS: Inbred male inbred C57BL/6J and DBA/2J mice were fed a lipogenic methyl-deficient diet, which causes liver injury that progresses to liver tumors. Differentially expressed microRNAs were identified by μParaflo microRNA microarray analysis and validated by quantitative reverse transcription PCR. RESULTS: We identified 74 significantly up- or down-regulated microRNAs, including miR-29c, miR-34a, miR-122, miR-155, miR-200b, miR-200c, and miR-221, in the livers of mice fed a methyl-deficient diet for 12 weeks as compared to their age-matched control mice. The targets for these microRNAs are known to affect cell proliferation, apoptosis, lipid metabolism, oxidative stress, DNA methylation, and inflammation. Interestingly, DBA/2J mice, which develop more extensive hepatic steatosis-specific pathomorphological changes, had a greater extent of miR-29c, miR-34a, miR-155, and miR-200b expression. CONCLUSIONS: These results demonstrate that alterations in expression of microRNAs are a prominent event during early stages of liver carcinogenesis induced by methyl deficiency. More importantly, our data link alterations in microRNA expression to the pathogenesis of liver cancer and strongly suggest that differences in the susceptibility to liver carcinogenesis may be determined by the differences in the microRNA expression response