Kiwifruit bZIP transcription factor AcePosF21 elicits ascorbic acid biosynthesis during cold stress.

Cold stress seriously affects plant development, resulting in heavy agricultural losses. L-ascorbic acid (AsA, vitamin C) is an antioxidant implicated in abiotic stress tolerance and metabolism of reactive oxygen species (ROS). Understanding whether and how cold stress elicits AsA biosynthesis to reduce oxidative damage is important for developing cold-resistant plants.

Kiwifruit MYBS1-like and GBF3 transcription factors influence l-ascorbic acid biosynthesis by activating transcription of GDP-L-galactose phosphorylase 3.

Plant-derived Vitamin C (l-ascorbic acid (AsA)) is crucial for human health and wellbeing and thus increasing AsA content is of interest to plant breeders. In plants GDP-l-galactose phosphorylase (GGP) is a key biosynthetic control step and here evidence is presented for two new transcriptional activators of GGP. AsA measurement, transcriptomics, transient expression, hormone application, gene editing, yeast 1/2-hybrid, and electromobility shift assay (EMSA) methods were used to identify two positively regulating transcription factors.

Peridermal fruit skin formation in Actinidia sp. (kiwifruit) is associated with genetic loci controlling russeting and cuticle formation.

Background: The skin (exocarp) of fleshy fruit is hugely diverse across species. Most fruit types have a live epidermal skin covered by a layer of cuticle made up of cutin while a few create an outermost layer of dead cells (peridermal layer).

Results: In this study we undertook crosses between epidermal and peridermal skinned kiwifruit, and showed that epidermal skin is a semi-dominant trait.

Elevating Ascorbate in Arabidopsis Stimulates the Production of Abscisic Acid, Phaseic Acid, and to a Lesser Extent Auxin (IAA) and Jasmonates, Resulting in Increased Expression of and Multiple Transcription Factors Associated with Abiotic Stress Tolerance.

Gene expression and phytohormone contents were measured in response to elevating ascorbate in the absence of other confounding stimuli such as high light and abiotic stresses. Young Arabidopsis plants were treated with 25 mM solutions of l-galactose pathway intermediates l-galactose (l-gal) or l-galactono-1,4-lactone (l-galL), as well as L-ascorbic acid (AsA), with 25 mM glucose used as control. Feeding increased rosette AsA 2- to 4-fold but there was little change in AsA biosynthetic gene transcripts.

A review of current knowledge about the formation of native peridermal exocarp in fruit.

The outer skin layer in any plant is essential in offering a protective barrier against water loss and pathogen attack. Within fleshy fruit, the skin supports internal cell layers and can provide the initial cues in attracting seed-dispersing animals. The skin of a fruit, termed the exocarp, is a key element of consumer preference and a target for many breeding programs.

Molecular Characterisation of a Supergene Conditioning Super-High Vitamin C in Kiwifruit Hybrids.

During analysis of kiwifruit derived from hybrids between the high vitamin C (ascorbic acid; AsA) species and , we observed bimodal segregation of fruit AsA concentration suggesting major gene segregation. To test this hypothesis, we performed whole-genome sequencing on pools of hybrid genotypes with either high or low AsA fruit. Pool-GWAS (genome-wide association study) revealed a single Quantitative Trait Locus (QTL) spanning more than 5 Mbp on chromosome 26, which we denote as qAsA26.

Enhanced ascorbate level improves multi-stress tolerance in a widely grown indica rice variety without compromising its agronomic characteristics.

A biotechnological approach was adopted for increasing foliar ascorbate levels as a strategy to adapt a widely grown high yielding rice variety to multiple abiotic stresses. The variety IR64 (Oryza sativa L. ssp.

A manually annotated Actinidia chinensis var. chinensis (kiwifruit) genome highlights the challenges associated with draft genomes and gene prediction in plants.

Background: Most published genome sequences are drafts, and most are dominated by computational gene prediction. Draft genomes typically incorporate considerable sequence data that are not assigned to chromosomes, and predicted genes without quality confidence measures. The current Actinidia chinensis (kiwifruit) 'Hongyang' draft genome has 164 Mb of sequences unassigned to pseudo-chromosomes, and omissions have been identified in the gene models.

Increasing ascorbate levels in crops to enhance human nutrition and plant abiotic stress tolerance.

Ascorbate (or vitamin C) is an essential human micronutrient predominantly obtained from plants. In addition to preventing scurvy, it is now known to have broader roles in human health, for example as a cofactor for enzymes involved in epigenetic programming and as regulator of cellular iron uptake. Furthermore, ascorbate is the major antioxidant in plants and underpins many environmentally induced abiotic stress responses.

The regulation of ascorbate biosynthesis.

We review the regulation of ascorbate (vitamin C) biosynthesis, focusing on the l-galactose pathway. We discuss the regulation of ascorbate biosynthesis at the level of gene transcription (both repression and enhancement) and translation (feedback inhibition of translation by ascorbate concentration) and discuss the eight proteins that have been demonstrated to date to affect ascorbate concentration in plant tissues. GDP-galactose phosphorylase (GGP) and GDP-mannose epimerase are critical steps that regulate ascorbate biosynthesis.

An upstream open reading frame is essential for feedback regulation of ascorbate biosynthesis in Arabidopsis.

Ascorbate (vitamin C) is an essential antioxidant and enzyme cofactor in both plants and animals. Ascorbate concentration is tightly regulated in plants, partly to respond to stress. Here, we demonstrate that ascorbate concentrations are determined via the posttranscriptional repression of GDP-l-galactose phosphorylase (GGP), a major control enzyme in the ascorbate biosynthesis pathway.

Diversity and relative levels of actinidin, kiwellin, and thaumatin-like allergens in 15 varieties of kiwifruit (Actinidia).

In the last 30 years the incidence of kiwifruit allergy has increased with the three major allergenic proteins being identified as actinidin, kiwellin, and thaumatin-like protein (TLP). We report wide variation in the levels of actinidin and TLP in 15 kiwifruit varieties from the four most widely cultivated Actinidia species. Acidic and basic isoforms of actinidin were identified in Actinidia deliciosa 'Hayward' and Actinidia arguta 'Hortgem Tahi', while only a basic isoform of actinidin was identified in Actinidia chinensis 'Hort16A'.

Investigation of ascorbate metabolism during inducement of storage disorders in pear.

In pear and apple, depletion of ascorbate has previously been associated with development of stress-related flesh browning. This disorder occurs in intact fruit and differs from browning associated with tissue maceration and processing. We investigated changes in ascorbate content, ascorbate peroxidase (APX) activities and gene expression of l-galactose pathway genes, ascorbate recycling genes and APXs from harvest to 30 days storage for three pear varieties ['Williams Bon Chretien' (WBC), 'Doyenne du Comice' and 'Beurre Bosc'].

Enhancing ascorbate in fruits and tubers through over-expression of the L-galactose pathway gene GDP-L-galactose phosphorylase.

Ascorbate, or vitamin C, is obtained by humans mostly from plant sources. Various approaches have been made to increase ascorbate in plants by transgenic means. Most of these attempts have involved leaf material from model plants, with little success reported using genes from the generally accepted l-galactose pathway of ascorbate biosynthesis.

Component-resolved diagnosis of kiwifruit allergy with purified natural and recombinant kiwifruit allergens.

Background: Kiwifruit is one of the most common causes of food allergic reactions. Component-resolved diagnostics may enable significantly improved detection of sensitization to kiwifruit.

Objective: To evaluate the use of individual allergens for component-resolved in vitro diagnosis of kiwifruit allergy.

Gene expression studies in kiwifruit and gene over-expression in Arabidopsis indicates that GDP-L-galactose guanyltransferase is a major control point of vitamin C biosynthesis.

Vitamin C (L-ascorbic acid, AsA) is an essential metabolite for plants and animals. Kiwifruit (Actinidia spp.) are a rich dietary source of AsA for humans.

Characterization of Bet v 1-related allergens from kiwifruit relevant for patients with combined kiwifruit and birch pollen allergy.

Allergy to kiwifruit appears to have become more common in Europe and elsewhere during the past several years. Seven allergens have been identified from kiwifruit so far, with actinidin, kiwellin and the thaumatin-like protein as the most relevant ones. In contrast to other fruits, no Bet v 1 homologues were characterized from kiwifruit so far.

Analysis of expressed sequence tags from Actinidia: applications of a cross species EST database for gene discovery in the areas of flavor, health, color and ripening.

Background: Kiwifruit (Actinidia spp.) are a relatively new, but economically important crop grown in many different parts of the world. Commercial success is driven by the development of new cultivars with novel consumer traits including flavor, appearance, healthful components and convenience.

Cardiac chamber hypertrophy following hematopoietic stem cell transplantation for primary immunodeficiency.

Children with primary immune deficiency (PID) who receive hematopoietic stem cell transplantation (HSCT) often suffer from graft-versus-host disease (GVHD), which is commonly treated with corticosteroids (CS). CS may cause hypertension, development of cardiac chamber hypertrophy (CCH), and left ventricular outflow tract obstruction (LVOTO). We followed the development of CCH and LVOTO by serial echocardiograms in 10 children with PID before and 6 to 12 weeks after HSCT, and correlated their development with age of transplant, GVHD, use of CS and hypertension.

Inferior outcomes for overweight children undergoing allogeneic stem cell transplantation.

This retrospective cohort study aimed at determining whether overweight children undergoing allogeneic stem cell transplantation (SCT) had inferior overall survival compared with children who were not overweight. Children >/=2 years of age who received allogeneic SCT were included. Overweight was defined as a body mass index >/= 95th percentile; 54/325 (17%) children were overweight.

The missing step of the L-galactose pathway of ascorbate biosynthesis in plants, an L-galactose guanyltransferase, increases leaf ascorbate content.

The gene for one postulated enzyme that converts GDP-L-galactose to L-galactose-1-phosphate is unknown in the L-galactose pathway of ascorbic acid biosynthesis and a possible candidate identified through map-based cloning is the uncharacterized gene At4g26850. We identified a putative function for At4g26850 using PSI-Blast and motif searching to show it was a member of the histidine triad superfamily, which includes D-galactose uridyltransferase. We cloned and expressed this Arabidopsis gene and the homologous gene from Actinidia chinensis in Escherichia coli and assayed the expressed protein for activities related to converting GDP-L-galactose to L-galactose-1-P.

Modification of gibberellin biosynthesis in the grafted apple scion allows control of tree height independent of the rootstock.

The availability of short stature apple scions that required minimal applications of chemical growth retardants and could be used with a range of rootstocks would be of considerable benefit to fruit growers. We have suppressed the expression of a gene encoding the gibberellin (GA) biosynthetic enzyme GA 20-oxidase to reduce the levels of bioactive GAs in a scion variety, resulting in significant reductions in stem height. Application of GA3 reversed the effect.

Meta-analysis of randomized controlled trials of prophylactic granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor after autologous and allogeneic stem cell transplantation.

Purpose: The primary objective of our meta-analysis was to determine whether prophylactic hematopoietic colony-stimulating factors (CSFs) after hematopoietic autologous and allogeneic stem-cell transplantation (SCT) reduced documented infections. Our secondary objectives were to determine whether prophylactic CSFs affected other outcomes including parenteral antibiotic therapy duration, infection-related mortality, graft-versus-host disease (GVHD), or treatment-related mortality.

Methods: We included studies if there was random assignment between CSFs and placebo/no therapy and CSFs were given after SCT and before recovery of neutrophils.