Antioxidant Responses and Redox Regulation Within Plant-Beneficial Microbe Interaction.

The increase in extreme climate events associated with global warming is a great menace to crop productivity nowadays. In addition to abiotic stresses, warmer conditions favor the spread of infectious diseases affecting plant performance. Within this context, beneficial microbes constitute a sustainable alternative for the mitigation of the effects of climate change on plant growth and productivity.

The Functional Relationship between NADPH Thioredoxin Reductase C, 2-Cys Peroxiredoxins, and -Type Thioredoxins in the Regulation of Calvin-Benson Cycle and Malate-Valve Enzymes in Arabidopsis.

The concerted regulation of chloroplast biosynthetic pathways and NADPH extrusion via malate valve depends on and thioredoxins (Trxs). The finding that decreased levels of the thiol-peroxidase 2-Cys peroxiredoxin (Prx) suppress the severe phenotype of Arabidopsis mutants lacking NADPH-dependent Trx reductase C (NTRC) and Trxs uncovered the central function of the NTRC-2-Cys-Prx redox system in chloroplast performance. These results suggest that Trxs are also regulated by this system; however, the functional relationship between NTRC, 2-Cys Prxs, and type Trxs is unknown.

Current Knowledge on Mechanisms Preventing Photosynthesis Redox Imbalance in Plants.

Photosynthesis includes a set of redox reactions that are the source of reducing power and energy for the assimilation of inorganic carbon, nitrogen and sulphur, thus generating organic compounds, and oxygen, which supports life on Earth. As sessile organisms, plants have to face continuous changes in environmental conditions and need to adjust the photosynthetic electron transport to prevent the accumulation of damaging oxygen by-products. The balance between photosynthetic cyclic and linear electron flows allows for the maintenance of a proper NADPH/ATP ratio that is adapted to the plant's needs.

Frailty Assessment in a Stable COPD Cohort: Is There a COPD-Frail Phenotype?

The frailty syndrome increases the morbidity/mortality in older adults, and several studies have shown a higher prevalence of this syndrome in patients with Chronic Obstructive Pulmonary Disease (COPD). The aim of this study was to identify the characteristics of frail patients with COPD to define a new phenotype called "COPD-frail." We conducted a cross-sectional study in a cohort of patients with stable COPD, classified as either frail, pre-frail, or non-frail.

Redox regulation of chloroplast metabolism.

Regulation of enzyme activity based on thiol-disulfide exchange is a regulatory mechanism in which the protein disulfide reductase activity of thioredoxins (TRXs) plays a central role. Plant chloroplasts are equipped with a complex set of up to 20 TRXs and TRX-like proteins, the activity of which is supported by reducing power provided by photosynthetically reduced ferredoxin (FDX) with the participation of a FDX-dependent TRX reductase (FTR). Therefore, the FDX-FTR-TRXs pathway allows the regulation of redox-sensitive chloroplast enzymes in response to light.

An event of alternative splicing affects the expression of the NTRC gene, encoding NADPH-thioredoxin reductase C, in seed plants.

The NTRC gene encodes a NADPH-dependent thioredoxin reductase with a joint thioredoxin domain, exclusive of photosynthetic organisms. An updated search shows that although most species harbor a single copy of the NTRC gene, two copies were identified in different species of the genus Solanum, Glycine max and the moss Physcomitrella patens. The phylogenetic analysis of NTRCs from different sources produced a tree with the major groups of photosynthetic organisms: cyanobacteria, algae and land plants, indicating the evolutionary success of the NTRC gene among photosynthetic eukaryotes.

Metabolic Control of Tobacco Pollination by Sugars and Invertases.

Pollination in flowering plants is initiated by germination of pollen grains on stigmas followed by fast growth of pollen tubes representing highly energy-consuming processes. The symplastic isolation of pollen grains and tubes requires import of Suc available in the apoplast. We show that the functional coupling of Suc cleavage by invertases and uptake of the released hexoses by monosaccharide transporters are critical for pollination in tobacco (Nicotiana tabacum).

Hormonal and metabolic regulation of tomato fruit sink activity and yield under salinity.

Salinization of water and soil has a negative impact on tomato (Solanum lycopersicum L.) productivity by reducing growth of sink organs and by inducing senescence in source leaves. It has been hypothesized that yield stability implies the maintenance or increase of sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves through changes in sucrolytic enzymes and their regulation by phytohormones.

Extracellular invertase is involved in the regulation of clubroot disease in Arabidopsis thaliana.

Clubroot disease of Brassicaceae is caused by an obligate biotrophic protist, Plasmodiophora brassicae. During root gall development, a strong sink for assimilates is developed. Among other genes involved in sucrose and starch synthesis and degradation, the increased expression of invertases has been observed in a microarray experiment, and invertase and invertase inhibitor expression was confirmed using promoter::GUS lines of Arabidopsis thaliana.

Fetal myocardial morphological and functional changes associated with well-controlled gestational diabetes.

Objective: To make a global evaluation of the fetal myocardial changes in a well-controlled gestational diabetic population.

Study Design: Twenty-four pregnant well-controlled diabetic patients were selected. Sixteen normal pregnancies were randomly collected as a control group.

Circadian and developmental regulation of vacuolar invertase expression in petioles of sugar beet plants.

The expression pattern of the genes coding for vacuolar and extracellular invertase activity was analyzed in sugar beet (Beta vulgaris) and compared with the expression of sucrose synthase in this important sucrose-storing crop. Northern blot analysis revealed that sucrose synthase is the predominant sucrose-cleaving enzyme in tap roots, whereas vacuolar invertase was specifically expressed in petioles. Extracellular invertase transcripts showed low abundance in all the sugar beet organs and were not detected in northern blots.

Abiotic stresses affecting water balance induce phosphoenolpyruvate carboxylase expression in roots of wheat seedlings.

Phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.

A germination-related gene encoding a serine carboxypeptidase is expressed during the differentiation of the vascular tissue in wheat grains and seedlings.

Carboxypeptidases expressed in the aleurone layer participate in the mobilization of endosperm storage proteins during cereal grain germination. The genes encoding these proteins are also expressed in the scutellum of germinating grains, but their function in this organ is not yet clear. We have analyzed the expression of a carboxypeptidase III (CPIII) gene in germinating wheat (Triticum aestivum L.

Optimized determination of calcium in grape juice, wines, and other alcoholic beverages by atomic absorption spectrometry.

This paper describes a study of the different methods of sample preparation for the determination of calcium in grape juice, wines, and other alcoholic beverages by flame atomic absorption spectrometry; results are also reported for the practical application of these methods to the analysis of commercial samples produced in Spain. The methods tested included dealcoholization, dry mineralization, and wet mineralization with heating by using different acids and/or mixtures of acids. The sensitivity, detection limit, accuracy, precision, and selectiviy of each method were established.