An Efficient Triplex TaqMan Quantitative PCR to Detect a Blackleg-Causing Lineage of in Potato Based on a Pangenome Analysis.

is an important bacterial pathogen causing blackleg (BL) in potatoes. Nevertheless, is often detected in seed lots that do not develop any of the typical blackleg symptoms in the potato crop when planted. Field bioassays identified that strains can be categorized into two distinct classes, some able to cause blackleg symptoms and some unable to do it.

Fruit softening: evidence for pectate lyase action in vivo in date (Phoenix dactylifera) and rosaceous fruit cell walls.

Background And Aims: The programmed softening occurring during fruit development requires scission of cell wall polysaccharides, especially pectin. Proposed mechanisms include the action of wall enzymes or hydroxyl radicals. Enzyme activities found in fruit extracts include pectate lyase (PL) and endo-polygalacturonase (EPG), which, in vitro, cleave de-esterified homogalacturonan in mid-chain by β-elimination and hydrolysis, respectively.

The Pectobacterium pangenome, with a focus on Pectobacterium brasiliense, shows a robust core and extensive exchange of genes from a shared gene pool.

Background: Bacterial plant pathogens of the Pectobacterium genus are responsible for a wide spectrum of diseases in plants, including important crops such as potato, tomato, lettuce, and banana. Investigation of the genetic diversity underlying virulence and host specificity can be performed at genome level by using a comprehensive comparative approach called pangenomics. A pangenomic approach, using newly developed functionalities in PanTools, was applied to analyze the complex phylogeny of the Pectobacterium genus.

Pectic polysaccharides are attacked by hydroxyl radicals in ripening fruit: evidence from a fluorescent fingerprinting method.

Background And Aims: Many fruits soften during ripening, which is important commercially and in rendering the fruit attractive to seed-dispersing animals. Cell-wall polysaccharide hydrolases may contribute to softening, but sometimes appear to be absent. An alternative hypothesis is that hydroxyl radicals ((•)OH) non-enzymically cleave wall polysaccharides.

Fingerprinting of hydroxyl radical-attacked polysaccharides by N-isopropyl-2-aminoacridone labelling.

Hydroxyl radicals (•OH) cause non-enzymic scission of polysaccharides in diverse biological systems. Such reactions can be detrimental (e.g.

Apple extract induces increased epithelial resistance and claudin 4 expression in Caco-2 cells.

Background: The small intestinal epithelium functions both to absorb nutrients, and to provide a barrier between the outside, luminal, world and the human body. One of the passageways across the intestinal epithelium is paracellular diffusion, which is controlled by the properties of tight junction complexes. We used a differentiated Caco-2 monolayer as a model for small intestinal epithelium to study the effect of crude apple extracts on paracellular permeability.

Normalization genes for quantitative RT-PCR in differentiated Caco-2 cells used for food exposure studies.

Exposure of food products to small-intestinal-like Caco-2 cells, combined with a gene expression based response analysis can be a valuable tool to classify potential bioactive effects of food homogenates. In order to study changes in gene expression upon food exposure, a robust set of stably expressed genes is required for normalization. Here we present a set of reference genes suitable for RT-qPCR that has been validated for exposure studies with the intestinal-like Caco-2 cell line.

Transcription profiles of LPS-stimulated THP-1 monocytes and macrophages: a tool to study inflammation modulating effects of food-derived compounds.

An assay was developed to study inflammation-related immune responses of food compounds on monocytes and macrophages derived from THP-1 cell line. First strategy focused on the effects after stimulation with either lipopolysaccharide (LPS) or Concanavalin A (ConA). Gene expression kinetics of inflammation-related cytokines (IL-1β, IL-6, IL-8, IL-10 and TNF-α), inflammation-related enzymes (iNOS and COX-2), and transcription factors (NF-κB, AP-1 and SP-1) were analyzed using RT-PCR.

In vivo cell wall loosening by hydroxyl radicals during cress seed germination and elongation growth.

Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical ((*)OH)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance spectroscopy to show that (*)OH is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativum; Brassicaceae) seeds.

Contrasting interactions between ethylene and abscisic acid in Rumex species differing in submergence tolerance.

Complete submergence of flooding-tolerant Rumex palustris plants strongly stimulates petiole elongation. This escape response is initiated by the accumulation of ethylene inside the submerged tissue. In contrast, petioles of flooding-intolerant Rumex acetosa do not increase their elongation rate under water even though ethylene also accumulates when they are submerged.

Ethylene regulates fast apoplastic acidification and expansin A transcription during submergence-induced petiole elongation in Rumex palustris.

The semi-aquatic dicot Rumex palustris responds to complete submergence by enhanced elongation of young petioles. This elongation of petiole cells brings leaf blades above the water surface, thus reinstating gas exchange with the atmosphere and increasing survival in flood-prone environments. We already know that an enhanced internal level of the gaseous hormone ethylene is the primary signal for underwater escape in R.

The roles of ethylene, auxin, abscisic acid, and gibberellin in the hyponastic growth of submerged Rumex palustris petioles.

Rumex palustris responds to complete submergence with upward movement of the younger petioles. This so-called hyponastic response, in combination with stimulated petiole elongation, brings the leaf blade above the water surface and restores contact with the atmosphere. We made a detailed study of this differential growth process, encompassing the complete range of the known signal transduction pathway: from the cellular localization of differential growth, to the hormonal regulation, and the possible involvement of a cell wall loosening protein (expansin) as a downstream target.

Submergence research using Rumex palustris as a model; looking back and going forward.

Flooding is a phenomenon that destroys many crops worldwide. During evolution several plant species evolved specialized mechanisms to survive short- or long-term waterlogging and even complete submergence. One of the plant species that evolved such a mechanism is Rumex palustris.