Arbuscular mycorrhizae (AM) are the most widespread mutualistic symbioses between the roots of most land plants and a phylum of soil fungi. AM are known to influence plant performance by improving mineral nutrition, protecting against pathogens and enhancing resistance or tolerance to biotic and abiotic stresses. The aim of this study was to investigate the frond proteome of the arsenic hyperaccumulator fern Pteris vittata in plants that had been inoculated with one of the two AM fungi (Glomus mosseae or Gigaspora margarita) with and without arsenic treatment. A protective role for AM fungi colonisation in the absence of arsenic was indicated by the down-regulation of oxidative damage-related proteins. Arsenic treatment of mycorrhizal ferns induced the differential expression of 130 leaf proteins with specific responses in G. mosseae- and Gi. margarita-colonised plants. Up-regulation of multiple forms of glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, and enolase, primarily in G. mosseae-inoculated plants, suggests a central role for glycolytic enzymes in arsenic metabolism. Moreover, a putative arsenic transporter, PgPOR29, has been identified as an up-regulated protein by arsenic treatment.

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting bacteria (PGPB) can increase the growth and yield of major crops, and improve the quality of fruits and leaves. However, little is known about their impact on seed composition. Plants were inoculated with AM fungi and/or the bacterial strain Pseudomonas fluorescens Pf4 and harvested after 7 months of growth in open-field conditions. Plant growth parameters were measured (biomass, length and circumference of spikes, number of grains per cob, grain yield, and grain size) and protein, lipid, and starch content in grains were determined. Plant growth and yield were increased by inoculation with the microorganisms. Moreover, spikes and grains of inoculated plants were bigger than those produced by uninoculated plants. Regarding grain composition, the bacterial strain increased grain starch content, especially the digestible components, whereas AM fungi-enhanced protein, especially zein, content. Plant inoculation with the fluorescent pseudomonad and mycorrhizal fungi resulted in additive effects on grain composition. Overall, results showed that the bacterial strain and the AM fungi promoted maize growth cultivated in field conditions and differentially affected the grain nutritional content. Consequently, targeted plant inoculation with beneficial microorganisms can lead to commodities fulfilling consumer and industrial requirements.

Microorganisms associated with Vitis vinifera (grapevine) can affect its growth, health and grape quality. The aim of this study was to unravel the biodiversity of the bacterial rhizosphere microbiota of grapevine in an integrated pest management vineyard located in Piedmont, Italy. Comparison between the microbial community structure in the bulk and rhizosphere soil (variable: space) were performed. Moreover, the possible shifts of the bulk and rhizosphere soil microbiota according to two phenological stages such as flowering and early fruit development (variable: time) were characterized. The grapevine microbiota was identified using metagenomics and next-generation sequencing. Biodiversity was higher in the rhizosphere than in the bulk soil, independent of the phenological stage. Actinobacteria were the dominant class with frequencies ≥ 50% in all the soil samples, followed by Proteobacteria, Gemmatimonadetes, and Bacteroidetes. While Actinobacteria and Proteobacteria are well-known as being dominant in soil, this is the first time the presence of Gemmatimonadetes has been observed in vineyard soils. Gaiella was the dominant genus of Actinobacteria in all the samples. Finally, the microbiota associated with grapevine differed from the bulk soil microbiota and these variations were independent of the phenological stage of the plant.

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A major aldehydic end product of the peroxidation of arachidonic acid, 4-hydroxy-2,3-nonenal (HNE), has recently been considered for its potential involvement in a variety of cell functions. Here we report on the differential regulation of rat hepatocyte protein kinase C (PKC) isoforms by concentrations of HNE actually detectable in specific biological fluids or tissues. PKC ␤I and, to a much greater extent, PKC ␤II activities were markedly increased by 0.1 mol/L HNE (final concentration in cell medium) whereas they were unaffected or even inhibited by 1 to 10 mol/L HNE. On the contrary, the calcium independent PKC ␦ activity was inhibited by 0.1 mol/L and increased by 1 and 10 mol/L. The carbonyl compound 4-hydroxy-2,3-nonenal (HNE) is one of the major products of the oxidative breakdown of -6 fatty acids, the featuring process of membrane lipid peroxidation. 1 This aldehyde, being strongly electrophylic, readily reacts at neutral or slightly alkaline pH with sulphydryl and amino groups. HNE production was quantified several years ago in rat liver microsomes and isolated hepatocytes undergoing various experimental conditions of enhanced lipid peroxidation. 2,3 In more recent in vivo experimental reproduction of liver 4 and arterial 5,6 fibrosclerotic lesions, the detectable steady-state HNE concentration reached the low-micromolar range, up to 5 to 10 µmol/L.Until rather recently, in vitro biochemical studies were oriented towards seeking evidence of the many biochemical effects of HNE, generally using concentrations above 10 µmol/L; these were normally performed by adding the aldehyde to cell cultures or suspensions or cellular subfractions. 1 Such an approach was adopted to counteract the high aldehyde metabolism shown by the majority of the cell types tested 7 ; however, it directed the investigation to quantities of HNE of rather unlikely biological interest. Further, the overall negative effects exerted by relatively high HNE dosage contributed to the short-sighted opinion that this and related lipid peroxidation products were simply detrimental and acutely toxic to cells and tissues and consequently were of limited interest in pathophysiology.This state of affairs was rectified in particular by extensive research on the role of oxidatively modified low density lipoproteins in the pathogenesis of atherosclerosis 8 and the detection in the human plasma of autoantibodies against HNE-modified low-density lipoproteins 9 or of HNE-modified proteins, 10 and a role of HNE in pathophysiology became more favorably considered.At present, because of the use of specific monoclonal antibodies raised against tissue HNE-protein adducts, the number of human diseases with detectable accumulation of HNE is rapidly growing: increased HNE levels have been recognized in the liver of patients with alcohol-induced Abbreviations: HNE, 4-hydroxy-2,3-nonenal; PKC, protein kinase C; CD, cathepsin D; DAG, diacylglycerol.From the