A gibberellin-assisted study of the transcriptional and hormonal changes occurring at floral transition in peach buds (Prunus persica L. Batsch).

Background: Flower load in peach is an important determinant of final fruit quality and is subjected to cost-effective agronomical practices, such as the thinning, to finely balance the sink-source relationships within the tree and drive the optimal amount of assimilates to the fruits. Floral transition in peach buds occurs as a result of the integration of specific environmental signals, such as light and temperature, into the endogenous pathways that induce the meristem to pass from vegetative to reproductive growth. The cross talk and integration of the different players, such as the genes and the hormones, are still partially unknown.

Apple fruit superficial scald resistance mediated by ethylene inhibition is associated with diverse metabolic processes.

Fruits stored at low temperature can exhibit different types of chilling injury. In apple, one of the most serious physiological disorders is superficial scald, which is characterized by discoloration and brown necrotic patches on the fruit exocarp. Although this phenomenon is widely ascribed to the oxidation of α-farnesene, its physiology is not yet fully understood.

Biological relevance of volatile organic compounds emitted during the pathogenic interactions between apple plants and Erwinia amylovora.

Volatile organic compounds emitted during the infection of apple (Malus pumila var. domestica) plants by Erwinia amylovora or Pseudomonas syringae pv. syringae were studied by gas chromatography-mass spectrometry and proton transfer reaction-mass spectrometry, and used to treat uninfected plants.

Comparison between in toto peach (Prunus persica L. Batsch) supplementation and its polyphenolic extract on rat liver xenobiotic metabolizing enzymes.

Over the past years, there has been a growing interest in the natural constituents of foods as a potential means of cancer control. To date, epidemiology studies seem to indicate an inverse association between regular consumption of fruit and vegetables and cancer risk. Here, the potential chemopreventive activity of the polyphenolic extract (PPE) of peach (Prunus persica L.

On the role of ethylene, auxin and a GOLVEN-like peptide hormone in the regulation of peach ripening.

Background: In melting flesh peaches, auxin is necessary for system-2 ethylene synthesis and a cross-talk between ethylene and auxin occurs during the ripening process. To elucidate this interaction at the transition from maturation to ripening and the accompanying switch from system-1 to system-2 ethylene biosynthesis, fruits of melting flesh and stony hard genotypes, the latter unable to produce system-2 ethylene because of insufficient amount of auxin at ripening, were treated with auxin, ethylene and with 1-methylcyclopropene (1-MCP), known to block ethylene receptors. The effects of the treatments on the different genotypes were monitored by hormone quantifications and transcription profiling.

Chilling-Induced Changes in Aroma Volatile Profiles in Tomato.

Fruit and vegetables are regularly stored by consumers in the refrigerator at temperatures that may be well below the recommended storage temperatures. Apart from causing visible symptoms such as watery, sunken areas on the skin, chilling may also induce changes in fruit textural properties and flavour. The aim of this research was to investigate the effect of low temperature storage on tomato flavour and off-flavour production.

Is there room for improving the nutraceutical composition of apple?

In this study, we assessed the main bioactive compounds of a broad apple germplasm collection, composed by 247 accessions of wild (97) and domesticated (150) species. Among the stilbenes, trans- and cis-piceid were found to be ubiquitary components of both wild and cultivated apples. Apple was suggested to be the second dietary source of resveratrols.

Target metabolite and gene transcription profiling during the development of superficial scald in apple (Malus x domestica Borkh).

Background: Fruit quality features resulting from ripening processes need to be preserved throughout storage for economical reasons. However, during this period several physiological disorders can occur, of which superficial scald is one of the most important, due to the development of large brown areas on the fruit skin surface.

Results: This study examined the variation in polyphenolic content with the progress of superficial scald in apple, also with respect to 1-MCP, an ethylene competitor interacting with the hormone receptors and known to interfere with this etiology.

A multidisciplinary approach providing new insight into fruit flesh browning physiology in apple (Malus x domestica Borkh.).

In terms of the quality of minimally processed fruit, flesh browning is fundamentally important in the development of an aesthetically unpleasant appearance, with consequent off-flavours. The development of browning depends on the enzymatic action of the polyphenol oxidase (PPO). In the 'Golden Delicious' apple genome ten PPO genes were initially identified and located on three main chromosomes (2, 5 and 10).

Transcriptional regulation of flavonoid biosynthesis in nectarine (Prunus persica) by a set of R2R3 MYB transcription factors.

Background: Flavonoids such as anthocyanins, flavonols and proanthocyanidins, play a central role in fruit colour, flavour and health attributes. In peach and nectarine (Prunus persica) these compounds vary during fruit growth and ripening. Flavonoids are produced by a well studied pathway which is transcriptionally regulated by members of the MYB and bHLH transcription factor families.

ABA may promote or delay peach fruit ripening through modulation of ripening- and hormone-related gene expression depending on the developmental stage.

Peach (Prunus persica laevis L. Batsch) was chosen as a model to further clarify the physiological role of ABA during fruit ripening. To this aim, branches bearing one fruit at mid-S3, S3/S4 and S4 stages of fruit development and characterized by a different ripening index (I(AD)), as revealed by a non-destructive device called a DA-meter, were treated with ABA (0.

Ethylene and auxin biosynthesis and signaling are impaired by methyl jasmonate leading to a transient slowing down of ripening in peach fruit.

Peach (Prunus persica) was chosen as a model to further clarify the physiological role of jasmonates (JAs) during fruit ripening. To this aim, the effect of methyl jasmonate (MJ, 0.88 mM), applied at a late stage (S3) of fruit development under field conditions (in planta), on the time-course of fruit ripening over a 14-day period was evaluated.

Rapid tomato volatile profiling by using proton-transfer reaction mass spectrometry (PTR-MS).

The availability of rapid and accurate methods to assess fruit flavor is of utmost importance to support quality control especially in the breeding phase. Breeders need more information and analytical tools to facilitate selection for complex multigenic traits such as flavor quality. In this study, it is shown that proton-transfer reaction mass spectrometry (PTR-MS) is a suitable method to monitor at high sensitivity the emission of volatiles determining the tomato aromatic profile such as hexanal, hexenals, methanol, ethanol, and acetaldehyde.

Spermidine application to young developing peach fruits leads to a slowing down of ripening by impairing ripening-related ethylene and auxin metabolism and signaling.

Peach (Prunus persica var. laevis Gray) was chosen to unravel the molecular basis underlying the ability of spermidine (Sd) to influence fruit development and ripening. Field applications of 1 mM Sd on peach fruit at an early developmental stage, 41 days after full bloom (dAFB), i.

Use of homologous and heterologous gene expression profiling tools to characterize transcription dynamics during apple fruit maturation and ripening.

Background: Fruit development, maturation and ripening consists of a complex series of biochemical and physiological changes that in climacteric fruits, including apple and tomato, are coordinated by the gaseous hormone ethylene. These changes lead to final fruit quality and understanding of the functional machinery underlying these processes is of both biological and practical importance. To date many reports have been made on the analysis of gene expression in apple.

Measuring flavonoid enzyme activities in tissues of fruit species.

Flavonoids are important secondary metabolites, which are ubiquitously present in plant-derived food. Since flavonoids may show beneficial effects on human health, there is increasing interest in the availability of plants with a tailor-made flavonoid spectrum. Determination of flavonoid enzyme activities and investigations into their substrate specificity are an important precondition for both classical and molecular approaches.

Jasmonate-induced ripening delay is associated with up-regulation of polyamine levels in peach fruit.

Methyl jasmonate (MJ, 0.20mM) and its synthetic analog n-propyl dihydrojasmonate (PDJ, 0.22mM) were applied to peach fruit (Prunus persica L.

Peach ( Prunus persica L. Batsch) allergen-encoding genes are developmentally regulated and affected by fruit load and light radiation.

The fruits of Rosaceae species may frequently induce allergic reactions in both adults and children, especially in the Mediterranean area. In peach, true allergens and cross-reactive proteins may cause hypersensitive reactions involving a wide diversity of symptoms. Three known classes of allergenic proteins, namely, Pru p 1, Pru p 3, and Pru p 4, have been reported to be mostly involved, but an exhaustive survey of the proteins determining the overall allergenic potential, their biological functions, and the factors affecting the expression of the related genes is still missing.

Jasmonate-induced transcriptional changes suggest a negative interference with the ripening syndrome in peach fruit.

Peach (Prunus persica L. Batsch) was chosen as a model to shed light on the physiological role of jasmonates (JAs) during fruit ripening. To this aim, the effects of methyl jasmonate (MJ, 0.

Transcription of ethylene perception and biosynthesis genes is altered by putrescine, spermidine and aminoethoxyvinylglycine (AVG) during ripening in peach fruit (Prunus persica).

The time course of ethylene biosynthesis and perception was investigated in ripening peach fruit (Prunus persica) following treatments with the polyamines putrescine (Pu) and spermidine (Sd), and with aminoethoxyvinylglycine (AVG). Fruit treatments were performed in planta. Ethylene production was measured by gas chromatography, and polyamine content by high-performance liquid chromatography; expression analyses were performed by Northern blot or real-time polymerase chain reaction.

Pigments in the fruit of red-fleshed kiwifruit (Actinidia chinensis and Actinidia deliciosa).

Kiwifruit cultivars (Actinidia chinensis and A. deliciosa) generally have fruit with yellow or green flesh when ripe. A small number of genotypes also have red pigments, usually restricted to the inner pericarp but varying in intensity and in distribution within the fruit.

Induction of antimicrobial 3-deoxyflavonoids in pome fruit trees controls fire blight.

Fire blight, a devastating bacterial disease in pome fruits, causes severe economic losses worldwide. Hitherto, an effective control could only be achieved by using antibiotics, but this implies potential risks for human health, livestock and environment. A new approach allows transient inhibition of a step in the flavonoid pathway, thereby inducing the formation of a novel antimicrobial 3-deoxyflavonoid controlling fire blight in apple and pear leaves.