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Ethylene has been well established as a hormone controlling almost all aspects of vegetative development (Smalle and Van Der Straeten, 1997). The response in dark-grown pea seedlings was the first physiological effect attributed to ethylene (Neljubow, 1901). [ABSTRACT FROM AUTHOR]

Abscission is a highly coordinated process in which organ detachment occurs in specific cell layers named abscission zone (Roberts et al. 2002). Ethylene and auxins are the major hormones involved and their interaction is believed to be of paramount importance during abscission activation (Taylor and Whitelaw 2001). [ABSTRACT FROM AUTHOR]

Plums have a limited postharvest life due to their elevated rate of ripening and because they can develop chilling injury after long cold storage, even when stored at optimal temperatures (0°C ± 0.5°C). Flesh browning and flesh translucency are the main symptoms and the susceptibility depends on the cultivar and storage temperature (Crisosto et al. 1999). [ABSTRACT FROM AUTHOR]

The ripening of fleshy fruit is generally distinguished into two categories, climacteric and non-climacteric, based on the fruit's ability to produce or ethylene in high concentrations during maturation. A gaseous hormone produced by higher plants, ethylene regulates a number of physiological processes ranging from fruit development to maturation and senescence (Yang and Hoffmann 1984; Giovannoni 2004). [ABSTRACT FROM AUTHOR]

1-Methylcyclopropene (1-MCP) is an inhibitor of ethylene binding that can prevent ethylene-dependent responses in many fruits and vegetables (Blankenship and Dole, 2003; Watkins, 2006). 1-MCP has been commercialized as SmartFresh and food use registration has been obtained for a wide range of crops in several countries (Watkins, 2006). [ABSTRACT FROM AUTHOR]

The control of the ripening process in climacteric fruit mainly relies on the possibility of affecting ethylene biosynthesis and action. This can be achieved through genetic manipulation, by modulating environmental parameters (temperature, atmosphere composition) during storage, or using specific inhibitors of ethylene biosynthesis/perception. The effects of treatments with ethylene inhibitors on climacteric fruit, however, differ according to several factors including genotype. [ABSTRACT FROM AUTHOR]

A model was previously proposed to explain how ACC deaminasecontaining plant growth-promoting bacteria can lower plant ethylene levels and in turn stimulate plant growth (Glick et al., 1998), especially under stress conditions. [ABSTRACT FROM AUTHOR]

The regulation of eukaryotic gene activity at the transcriptional level involves multiprotein complexes and requires the concerted action of transcription factors and coactivator proteins. Transcription factors bind to DNA in a sequence-specific manner and essentially mark a gene for activation or repression through the recruitment of coactivator or corepressor proteins (Spiegelman and Heinrich, 2004). [ABSTRACT FROM AUTHOR]

Botrytis cinerea (teleomorph, Botryotinia fuckeliana), more commonly known as the cause of grey mould, has a wide host range of over 200 plant species, including many economically important crops such as tomato, grape and potato. This necrotrophic fungus secretes cell wall degrading enzymes which kill host plant tissue in advance of its own growth, metabolising any nutrients that are released (Govrin and Levine, 2000). [ABSTRACT FROM AUTHOR]

Herbivore-induced plant volatiles (HIPVs) contribute to attracting the natural enemies of the herbivores and, hence, benefit the plant indirectly. Volatile terpenoids are the major products among the HIPVs from legumes, e.g., lima bean (Phaseolus lunatus) and Medicago truncatula (Leitner et al., 2005). [ABSTRACT FROM AUTHOR]

Chemical-induced cell death was studied in suspension-cultured tomato (Lycopersicon esculentum Mill.) cells (line MsK8) treated with the anticancer drug camptothecin (CPT) and the heavy metal CdSO4. Within 24 h, chemical treatment induced cell death in a concentration-dependent manner. [ABSTRACT FROM AUTHOR]

Ethylene has long been regarded as a stress hormone. However, the roles of the ethylene signaling in abiotic stress responses remain an open question. Previously, we have cloned tobacco ethylene receptor genes NTHK1 and NTHK2, and studied their expression in response to different abiotic stresses. We found that both genes were induced by wounding and dehydration (Zhang et al., 2001a; Zhang et al., 2001b). [ABSTRACT FROM AUTHOR]

To protect themselves from disease, plants have evolved sophisticated defense mechanisms in which the signal molecules salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) often play crucial role (Pieterse and Van Loon, 1999). Elucidation of signaling pathways controlling disease resistance is a major objective in research on plant-pathogen interactions. The capacity of a plant to develop a broad-spectrum, systemic acquired resistance (SAR) after primary infection with a necrotizing pathogen is well known and its signal transduction pathway extensively studied (Durrant and Dong, 2004). [ABSTRACT FROM AUTHOR]

The circadian clock is an endogenous cellular mechanism which allows organisms to anticipate daily environmental changes resulting from the earth's rotation on its axis (Alabadi et al., 2001). A wide variety of physiological and behavior responses in plants, animals, and some prokaryotes are regulated by the clock (Harmer et al., 2001; Young and Kay, 2001; McClung, 2006). [ABSTRACT FROM AUTHOR]

Senescence represents the last stage of flower development, ultimately culminating in the death of the petals. The senescence program is regulated by coordinated changes in gene and protein expression, and the later stages of senescence share many characteristics of programmed cell death. [ABSTRACT FROM AUTHOR]

Early abscission or detachment of an organ from the main body of a plant can result in unwanted crop loss and decrease in the quality of the fruit harvested. For many decades it has been observed that gassing plants with ethylene will often hasten abscission, and greenhouse flower growers are careful to avoid any unwanted ethylene. As new genes regulating abscis sion are identified, scientists have also begun to try to understand how these genes interact with genes regulating ethylene and other hormone responses. Gene expression and genetic analysis indicates that ethylene can affect the abscission process at two distinct phases during the abscission process. [ABSTRACT FROM AUTHOR]

The physiological and biochemical processes that fruit undergo during development and maturation change the fruit's general composition. Besides the important evolution of chemical compounds involved in determining color, flavor/aroma formation, and sugar/acid content, modification of flesh firmness is one of the major changes occurring in fruit at the onset of ripening. While softening starts at the beginning of maturation, it peaks most notably during the last stage of fruit ripening in concomitance with ethylene burst. [ABSTRACT FROM AUTHOR]

Peel appearance of banana fruit is an important quality criteria that influences consumer acceptability. Many studies have shown promising results with the use of the ethylene antagonist 1-methylcyclopropene (1-MCP) on extending green life and shelf life of bananas (Macnish et al. 1997, 2000; Golding et al. 1998; Jiang et al. 1999; Harris et al. 2000). [ABSTRACT FROM AUTHOR]

‘Raínha Claudia verde' plums fruits are usually stored at 0-2°C. This cultivar has a small commercial period because of its short postharvest life. In cold chambers fruits became soft very quickly and were not adequate for sale. [ABSTRACT FROM AUTHOR]

Physiologists have historically divided ripening into two general classi- fications, climacteric and nonclimacteric, based on the presence or absence of dramatic ripening-related increases in respiration, respectively (Biale and Young, 1981). This concept is fundamental to any discussion of ethylene in postharvest systems. Two reviews of this topic (Biale and Young, 1981; Goldschmidt, 1997) concluded that both categories represent an oversimplification. [ABSTRACT FROM AUTHOR]

Aroma volatiles are important components of the sensory quality of fruit. In recent decades, the long shelf-life character has been introduced into commercial varieties of fruit such as tomatoes or melons through the use, in breeding programmes, of mutants impaired for ethylene perception. Extension of shelf life has resulted in a strong reduction of aroma volatiles production indicating a negative correlation between aroma production and ethylene perception or synthesis. [ABSTRACT FROM AUTHOR]

Physiological and molecular evidence supported the autocatalytic ethylene production in young "Star Ruby" grapefruit and "Murcott" mandarins, and the autoinhibitory ethylene production in mature fruit. Ethylene upregulated expression of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) in both fruitlets and mature "Star Ruby", and increased acetaldehyde (AA) and ethanol production, while ethylene action inhibitors counteracted the effect. N2 not only changed the expression of genes for ethylene biosynthesis but also genes for ethylene perception in both young and mature fruits. [ABSTRACT FROM AUTHOR]

Ethylene plays a role in many developmental processes among which fruit ripening has practical importance to the human diet. Peach is a climacteric fruit whose ripening, characterized by increased ethylene production, is accompanied by dramatic changes in colour, flavour, aroma and flesh texture. [ABSTRACT FROM AUTHOR]

1-methylcyclopropene (1-MCP), an ethylene antagonist, is an effective device to improve the shelf life and quality of fruits, vegetables and ornamentals. It also represents an useful tool in studies aimed at clarifying the ethylene physiology in plants. Peaches and nectarines are climacteric fruits which exhibit a sharp rise in ethylene synthesis at the onset of ripening associated with changes in colour, texture, aroma and other biochemical features. [ABSTRACT FROM AUTHOR]

Ethylene is involved in the regulation of many physiological responses throughout plant development. In Petunia × hybrida "Mitchell Diploid" (MD), a rapid increase in endogenous ethylene is synthesized in the ovary coinciding with fertilization, and signaling a change in floral function from one of pollinator attraction to one of seed development. Following treatment of petunia flowers with exogenous ethylene, 76% of human olfactory panelists correctly identify a difference in floral aroma when compared to the control (air treatment). [ABSTRACT FROM AUTHOR]

In flowering plants, double fertilization involves a complex series of interactions between essentially three plants - male gametophyte, female gametophyte, and sporophyte - culminating in the fusion of sexual cells and nuclei and the formation of an embryo and endosperm. The progamic phase of fertilization that consists in delivery of sperms to ovule and includes a cascade of events triggering pollen germination on the surface of stigma and growth of pollen tubes within tissues of the style and ovary plays a crucial role. [ABSTRACT FROM AUTHOR]

It is generally accepted that ethylene is a potent hormone involved in regulation of many events in plant growth and development (Abeles, 1973). Ethylene is produced and released from fungi and bacteria as well as from higher plants. [ABSTRACT FROM AUTHOR]

It has been well established that plants are able to fine tune phytohormone responses by control of synthesis and/or perception. Ethylene biosynthesis has been widely studied in a number of species but none more than Arabidopsis and tomato. Tomato provides a unique system to study ethylene biosynthesis because of the large, climacteric-associated increase in production at the onset of ripening. [ABSTRACT FROM AUTHOR]

Jasmonates (JAs) including jasmonic acid (JA) and methyl jasmonate (MeJA) are a family of cyclopentanone compounds synthesised from linolenic acid via the octadecanoic pathway. In Arabidopsis, JAs inhibit root elongation (Staswick et al., 1992) and are required for pollen development, anther dehiscence (Feys et al., 1994; McConn and Browse, 1996; Sanders et al., 2000), and defence against insects (McConn et al., 1997), necrotrophic pathogens (Thomma et al., 1999) and mechanical wounding. [ABSTRACT FROM AUTHOR]

The quality of flowering potted plants is defined by the interaction of many factors - noticeable and hides, qualitative and quantitative - that are involved in the visual appearance and the ability to preserve the ornamental characteristics. The most important parameter of quality for the flowering potted plants is obviously the flower. The natural senescence of flower is characterized by cascade events that are genetically regulated (Jones and Woodson, 1997). [ABSTRACT FROM AUTHOR]

It was hypothesized that methyl jasmonate (MJ) influences the binding of ethylene (C2H4) to membrane bound receptors. To address this question, C2H4 binding experiments were conducted in the presence of MJ using Saccharomyces cerevisiae that transgenically expresses the Arabidopsis thaliana ETR1 C2H4 receptor. [ABSTRACT FROM AUTHOR]

The phytohormone ethylene plays a central role in physiological and developmental processes, such as germination, growth, flower initiation, senescence of leaves and flowers, organ abscission, and fruit ripening (Abeles et al., 1992). It is also a major signal, mediating responses to a range of biotic and abiotic stresses. At the level of gene expression, ethylene has been shown to induce transcription of a wide range of genes involved in wound signalling and defense against pathogens. A family of five receptors mediates ethylene perception in Arabidopsis: ETR1, ERS1, ETR2, ERS2, and EIN4 (Hua and Meyerowitz, 1998; Sakai et al., 1998). The ETR1 receptor is a homodimer localized in the endoplasmic reticulum membrane (Chen et al., 2002). [ABSTRACT FROM AUTHOR]

Plants perceive a plethora of external signals and continuously adapt to changes in their environment. This phenotypic plasticity is obtained by integration of external signals as light and temperature, with internal, mainly hormonal signals that regulate development (Vandenbussche and Van Der Straeten, 2004). [ABSTRACT FROM AUTHOR]

Natural rubber is mostly produced by H. brasiliensis and represents 33% of total consumed rubber in the world, its production reaching 7.92 million tons in 2003. Heveaculture takes advantage of the increase in demand for natural rubber and the ecological challenges (carbon sequestration) to be a major renewable source of rubber and wood. [ABSTRACT FROM AUTHOR]

Export bananas (Musa acuminata, cv Cavendish) of the French West Indies are usually subjected to the "mixed-ripe" and/or "ship-ripe" processes during transit with a rapid deterioration of their quality. We hypothesized that this post harvest process is associated with the level of fruit ethylene responsiveness at harvest time. We attempted to obtain insight at the molecular level by identifying related candidate genes, which could be used as markers to improve the post harvest quality of fruit. [ABSTRACT FROM AUTHOR]

Ethylene perception and signal transduction involves a multistep pathway, in which ethylene receptors act at the first step and play a crucial role by negatively regulating ethylene responses (Chang and Stadler, 2001). In this respect, ethylene receptors have received considerable attention, as knowledge regarding this system would provide important contributions to our understanding of the mechanisms of ethylene signaling, and also provide the means to develop effective approaches for engineering ethylene sensitivity in plants. To better understand the biochemical mechanism of ethylene receptor action, we examined the subcellular localization and membrane topology that are important determinants of the biochemical functions of multispanning membrane proteins. [ABSTRACT FROM AUTHOR]

The miniature potted roses are popular greenhouse crops in many parts of the world. In the 1980s the introduction of new varieties had a dramatic impact on the European and North American markets. Current world production is estimated at around 100 million pots yearly. Major centers of production include Denmark, the Netherlands, the United States, Canada and Japan with production also in France, Germany and Italy (Pemberton et al., 2003). [ABSTRACT FROM AUTHOR]

The known components involved in ethylene signaling generally form a linear pathway model, beginning with ethylene binding at the receptors and resulting in the activation of ethylene-response genes (Guo and Ecker, 2004). Elucidation of this pathway has been possible through the isolation of genetic mutants displaying altered responses to ethylene. Arabidopsis seedlings grown in the dark in the presence of ethylene exhibit a "triple response", which consists of inhibition of hypocotyl and root elongation, radial swelling of the hypocotyl, and an exaggerated curvature of the apical hook (Bleecker et al., 1988; Guzman and Ecker, 1990). [ABSTRACT FROM AUTHOR]

The phytohormone ethylene is well known to influence a number of physiological and developmental processes in plants including but not limited to seed germination, seedling growth, formation of the apical hook, senescence, fruit ripening, abscission, and gravitropism (Abeles et al. 1992). [ABSTRACT FROM AUTHOR]

Abscission is preceded by the production of an abscission zone or layer at the base of organ. Abscission zone cells are not greatly different anatomically from the surrounding cells, but typically they are smaller and less vacuolated. Anatomical studies reveal almost complete disappearance of the middle lamella and extensive swelling and disorganization of the microfibrils in the primary wall in abscission zone cells. This changes result from the combined activities of several degrading enzymes. Several of these enzymes have been shown to be regulated by ethylene (Sexton and Roberts, 1982). [ABSTRACT FROM AUTHOR]

Seedling establishment is one of the most important agronomic traits in direct seeding rice cultivation. It has been considered that plant growth regulators (PGRs), such as gibberellin (GA) and ethylene, have promotive effects on rice seedling organs (Takahashi and Kaufman, 1983). [ABSTRACT FROM AUTHOR]

‘Blanquilla' pear (Pyrus communis) has delicious fragrance and flavour and represents an important produce for Spanish retailers. Although refrigeration can be used to prolong its storage, fruit ripens very quickly, even during cold storage, and therefore has a limited commercial life. This fruit is also very sensitive to mechanical bruising and can develop scald during long-term storage. In order to eliminate these specific problems, fruit were treated with 1-MCP and kept in air storage during 4 months. In general, in these conditions the fruit remain evergreen and the ripening process is blocked (Bai 2006, Trinchero et al. 2004). To solve this problem, combined treatments that mixed 1-MCP treatment and heat treatment to induce ripening were assayed. [ABSTRACT FROM AUTHOR]

Dicotyledonous plants need to reduce Fe(III) to Fe(II), mediated by a ferric reductase (encoded by the FRO2 gene in Arabidopsis), prior to its uptake through an Fe(II) transporter (encoded by the IRT1 gene in Arabidopsis). The expression of both genes is up-regulated under Fe deficiency. In the last years evidence has been presented to support a role for ethylene as activator of the ferric reductase activity but it is not known whether ethylene affects FRO2 transcription or other aspects of this activity (Romera and Alcántara, 2004). [ABSTRACT FROM AUTHOR]

We present a new approach to study the pathogen-host interaction by online monitoring of ethylene release using a laser-based photoacoustic detector. The instrument allows detection of ethylene emission in a continuous flow system down to 10 pptv (pptv = parts-per-trillion volume, 1:1012) (Bijnen et al., 1996) and has relatively high time resolution for measuring the dynamics of ethylene production by B. cinerea in vitro and by infected tomatoes. Moreover, it has been proved to be a powerful tool to study the relationship between ethylene released by the fungus in vitro and the enhanced ethylene production in B. cinerea infected tomato with respect to disease development. [ABSTRACT FROM AUTHOR]

Stratospheric ozone (O3) protects life from detrimental ultraviolet-B radiation, but tropospheric O3 is a serious world-wide pollutant. It is generally accepted that O3 initiates an oxidative burst and an active production of reactive oxygen species (ROS). Several signal molecules like ethylene (ET), jasmonic acid (JA), salicylic acid (SA) and nitric oxide (NO) have been hypothesized to act as a second or third messengers for O3-induced gene expression. Using a pharmacological approach, the aim of this work was to inspect the time course of the NO, SA and ET accumulation under ozone stress in the O3-sensitive tobacco cv BelW3 and the cross talk between these signaling molecules. [ABSTRACT FROM AUTHOR]

In zucchini (Cucurbita pepo), different cultivars present a distinctive floral abscission capacity. In greenhouses in the south-east of Spain, the summer conditions (high temperatures and long days) promote the production of bisexual flowers with an inhibition in the floral abscission during fruit formation (‘sticky flower' syndrome) (Gòmez et al., 2004). [ABSTRACT FROM AUTHOR]

Azorina vidalii (Campanulaceae) is an ornamental shrub native to Azores that produces long stems bearing many pink waxy bells on the terminal raceme (Crook, 1951). This study explored the sensitivity to exogenous ethylene of Azorina vidalii flowers in relation to their developmental stage in conformity with an approach to select new crops for ornamental purposes (Vonk Noordegraaf, 2000). [ABSTRACT FROM AUTHOR]

Pistillate flower abortion (PFA), induced by excessive pollen load on female flowers and leading eventually to their abscission, affects severely fruit set and potential fruit yield in ‘Serr' walnut variety. Such variety, owing to its nut quality, is extensively planted in Chile and in other walnut-producing areas in the world (California). [ABSTRACT FROM AUTHOR]

Ethylene and auxin (IAA) are important regulators of abscission. IAA retards, whilst ethylene is a potent accelerator of the process. The general rule portrays that provided the flux of IAA to the abscission zone region is maintained; the cell separation is inhibited and abscission does not occur (Addicott, 1982; Brown, 1997). [ABSTRACT FROM AUTHOR]

The use of natural or transgenic mutants is one of the ways to investigate specific physiological pathways in model plants such as Arabidopsis and tomato. In peach, a natural mutant (named slow ripening, slr), originated from a free pollination of the cv Fantasia, a yellow-fleshed nectarine, is characterized by a block of fruit development and an altered ripening pattern (no softening, pale yellow color). [ABSTRACT FROM AUTHOR]