Synergistic Action of Mild Heat and Essential Oil Treatments on Culturability and Viability of ATCC 25922 Tested In Vitro and in Fruit Juice.

The strengthening effect of a mild temperature treatment on the antimicrobial efficacy of essential oils has been widely reported, often leading to an underestimation or a misinterpretation of the product’s microbial status. In the present study, both a traditional culture-based method and Flow Cytometry (FCM) were applied to monitor the individual or combined effect of Origanum vulgare essential oil (OEO) and mild heat treatment on the culturability and viability of Escherichia coli in a conventional culture medium and in a fruit juice challenge test. The results obtained in the culture medium showed bacterial inactivation with an increasing treatment temperature (55 °C, 60 °C, 65 °C), highlighting an overestimation of the dead population using the culture-based method; in fact, when the FCM method was applied, the prevalence of injured bacterial cells in a viable but non-culturable (VBNC) state was observed.

Chromosome analysis and sorting.

Flow cytometric analysis and sorting of plant mitotic chromosomes has been mastered by only a few laboratories worldwide. Yet, it has been contributing significantly to progress in plant genetics, including the production of genome assemblies and the cloning of important genes. The dissection of complex genomes by flow sorting into the individual chromosomes that represent small parts of the genome reduces DNA sample complexity and streamlines projects relying on molecular and genomic techniques.

A Cross between Bread Wheat and a 2D(2R) Disomic Substitution Triticale Line Leads to the Formation of a Novel Disomic Addition Line and Provides Information of the Role of Rye Secalins on Breadmaking Characteristics.

A bread wheat line (N11) and a disomic 2D(2R) substitution triticale line were crossed and backrossed four times. At each step electrophoretic selection for the seeds that possessed, simultaneously, the complete set of high molecular weight glutenin subunits of N11 and the two high molecular weight secalins of rye, present in the 2D(2R) line, was carried out. Molecular cytogenetic analyses of the BCF generation revealed that the selection carried out produced a disomic addition line (2n = 44).

First detailed karyo-morphological analysis and molecular cytological study of leafy cardoon and globe artichoke, two multi-use Asteraceae crops.

Traditionally globe artichoke and leafy cardoon have been cultivated for use as vegetables but these crops are now finding multiple new roles in applications ranging from paper production to cheese preparation and biofuel use, with interest in their functional food potential. So far, their chromosome complements have been poorly investigated and a well-defined karyotype was not available. In this paper, a detailed karyo-morphological analysis and molecular cytogenetic studies were conducted on globe artichoke (Cynara cardunculus Linnaeus, 1753 var.

Production of a tumour-targeting antibody with a human-compatible glycosylation profile in N. benthamiana hairy root cultures.

Hairy root (HR) cultures derived from Agrobacterium rhizogenes transformation of plant tissues are an advantageous biotechnological manufacturing platform due to the accumulation of recombinant proteins in an otherwise largely protein free culture medium. In this context, HRs descending from transgenic Nicotiana tabacum plants were successfully used for the production of several functional mAbs with plant-type glycans. Here, we expressed the tumor-targeting monoclonal antibody mAb H10 in HRs obtained either by infecting a transgenic N.

FISHIS: fluorescence in situ hybridization in suspension and chromosome flow sorting made easy.

The large size and complex polyploid nature of many genomes has often hampered genomics development, as is the case for several plants of high agronomic value. Isolating single chromosomes or chromosome arms via flow sorting offers a clue to resolve such complexity by focusing sequencing to a discrete and self-consistent part of the whole genome. The occurrence of sufficient differences in the size and or base-pair composition of the individual chromosomes, which is uncommon in plants, is critical for the success of flow sorting.

Flow sorting and molecular cytogenetic identification of individual chromosomes of Dasypyrum villosum L. (H. villosa) by a single DNA probe.

Dasypyrum villosum (L.) Candargy (sin. Haynaldia villosa) is an annual wild diploid grass species (2n = 2x = 14; genome VV) belonging to the Poaceae family, which is considered to be an important source of biotic and abiotic stress resistance genes for wheat breeding.

Perturbation of polyamine catabolism can strongly affect root development and xylem differentiation.

Spermidine (Spd) treatment inhibited root cell elongation, promoted deposition of phenolics in cell walls of rhizodermis, xylem elements, and vascular parenchyma, and resulted in a higher number of cells resting in G(1) and G(2) phases in the maize (Zea mays) primary root apex. Furthermore, Spd treatment induced nuclear condensation and DNA fragmentation as well as precocious differentiation and cell death in both early metaxylem and late metaxylem precursors. Treatment with either N-prenylagmatine, a selective inhibitor of polyamine oxidase (PAO) enzyme activity, or N,N(1)-dimethylthiourea, a hydrogen peroxide (H(2)O(2)) scavenger, reverted Spd-induced autofluorescence intensification, DNA fragmentation, inhibition of root cell elongation, as well as reduction of percentage of nuclei in S phase.

Flow analysis and sorting of plant chromosomes.

The use of flow cytometry for evaluation of plant chromosomes requires some specialized attention to preparation and instrumentation. This unit deals exclusively with plant cytogenetics and presents an outline of this area as well as methods for accumulation of cells in metaphase, preparation of chromosome suspensions, flow analysis and sorting of chromosomes, and processing of the sorted chromosomes. Each method is described in tremendous detail because in many aspects dealing with plant cells is quite different from dealing with mammalian cells.

Saponaria officinalis karyology and karyotype by means of image analyzer and atomic force microscopy.

The aim of this work was to offer a contribution to the characterization of taxonomic entity of Saponaria officinalis (2n = 28; an herbaceous perennial species; saporin, a type 1 Ribosome Inactivating Protein, is present in leaves and seeds) by a cytogenetic and karyomorphological approach. We investigated the karyotype's morphometry correlated with Stebbin's symmetric index; the same information has been used for computing the indices resemblance between chromosomes (REC), symmetric indices (SYI), and total form (TF%) which allow the comparison between species and evaluation of karyological evolution. Fluorescence intensities of the stained nuclei were measured by a flow cytometer and, for the first time, values for nuclear DNA content were estimated by comparing nuclei fluorescence intensities of the test population with those of appropriate internal DNA standards.

Chromosome sorting in tetraploid wheat and its potential for genome analysis.

This study evaluates the potential of flow cytometry for chromosome sorting in durum wheat (Triticum turgidum Desf. var. durum, 2n = 4x = 28).

Identification of zygotic and nucellar seedlings in citrus interploid crosses by means of isozymes, flow cytometry and ISSR-PCR.

'Milam' (a purported hybrid of Citrus jambhiri Lush) + 'Femminello' lemon (Citrus limon L. Burm. f.

Bivariate flow cytometry DNA/BrdUrd analysis of plant cell cycle.

We describe a protocol for flow cytometry analysis of cell cycle in plants using indirect immunolabelling staining and Vicia faba, Pisum sativum and Zea mays root tip cells as model systems. The protocol is based on simultaneous analysis of two fluorescent signals. The first, obtained after staining with propidium iodide, is used to quantify nuclear DNA content.

Cell cycle synchronization in plant root meristems.

The analysis of structure and metabolism of a cell at a defined phase of cell cycle is often difficult because cell cycle progression in somatic tissues is asynchronous and only a fraction of cells are cycling. An elegant solution to obtain populations of cells enriched for single stage of the cell cycle is to impose the synchrony artificially. Different systems have been used to obtain synchronized populations of plant cells, including suspension-cultured cells, leaf mesophyll protoplasts and root tip meristems.

DNA content differences in laboratory mouse strains determined by flow cytometry.

The nuclear DNA content of seven mouse laboratory strains has been measured by flow cytometry. The differences observed between strains as well as those between sexes within the strain were all statistically significant. The highest DNA content (approximately 6.

Bivariate flow karyotyping in broad bean (Vicia faba).

In the present study, we report on the development of bivariate flow karyotyping in the legume broad bean (Vicia faba). We optimised chromosome staining with 4',6-diamidino-2-phenylindole and mithramycin A and analysed chromosome suspensions prepared from a line with standard (wild-type) karyotype and from six translocation lines with reconstructed karyotypes. Chromosomes were isolated from formaldehyde-fixed root tips after cell cycle synchronisation, and their fluorescence was analysed with dual-laser flow cytometry after the staining.

Construction of chromosome-specific DNA libraries covering the whole genome of field bean (Vicia faba L.).

Recombinant DNA libraries were constructed for seven chromosome types isolated from two translocation lines of field bean (Vicia faba L.) with reconstructed karyotypes. The chromosomes were selected so that the set of libraries covers the whole V.

Preparation of pea (Pisum sativum L.) chromosome and nucleus suspensions from single root tips.

A high-yield method for the isolation of intact nuclei and chromosomes in suspension from a variable number of pea root tips (1-10) has been developed. This procedure is based on a two-step cell-cycle synchronization of root-tip meristems to obtain a high mitotic index, followed by formaldehyde fixation and mechanical isolation of chromosomes and nuclei by homogenization. In the explant, up to 50% of metaphases were induced through a synchronization of the cell cycle at the G1/S interface with hydroxyurea (1.

Primer-induced labeling of pea and field bean chromosomes in situ and in suspension.

A protocol for primed in situ DNA labeling (PRINS) was optimized for pea (Pisum sativum L.) and field bean (Vicia faba L.) chromosomes attached to coverslips.

High-resolution flow karyotyping and chromosome sorting in Vicia faba lines with standard and reconstructed karyotypes.

Flow cytometric analysis has been performed on chromosomes isolated from formaldehyde-fixed root tips in a Vicia faba (2n = 12) line with a standard (wild-type) karyotype and in six V. faba translocation lines with reconstructed karyotypes. The resolution of individual chromosome types on histograms of chromosome fluorescence intensity (flow karyotypes) depended on the type of fluorochrome used for chromosome staining.

Localization of seed protein genes on flow-sorted field bean chromosomes.

Chromosomes from reconstructed field bean (Vicia faba L.) karyotypes were flow-sorted and the DNA was used for the physical localization of seed storage and nonstorage (USP) protein genes using PCR with sequence specific primers. The data were confirmed and refined by using DNA of microisolated chromosomes of other karyotypes as the target for PCR.