Role of Ethylene in Fruit Ripening (original) (raw)
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The process of fruit ripening is normally viewed distinctly in climacteric and non-climacteric fruits. But, many fruits such as guava, melon, Japanese plum, Asian pear and pepper show climacteric as well as non-climacteric behaviour depending on the cultivar or genotype. Investigations on in planta levels of CO2 and ethylene at various stages of fruits during ripening supported the role and involvement of changes in the rate of respiration and ethylene production in non-climacteric fruits such as strawberry, grapes and citrus. Non-climacteric fruits are also reported to respond to the exogenous application of ethylene. Comparative analysis of plant-attached and plant-detached fruits did not show similarity in their ripening behaviour. This disparity is being explained in view of 1. Hypothetical ripening inhibitor, 2. Differences in the production, release and endogenous levels of ethylene, 3. Sensitivity of fruits towards ethylene and 4. Variations in the gaseous microenvironment among fruits and their varieties. Detailed studies on genetic and inheritance patterns along with the application of '-omics' research indicated that ethylene-dependent and ethylene-independent pathways coexist in both climacteric and non-climacteric fruits. Auxin levels also interact with ethylene in regulating ripening. These findings therefore reveal that the classification of fruits based on climacteric rise and/or ethylene production status is not very distinct or perfect. However, presence of a characteristic rise in CO2 levels and a burst in ethylene production in some non-climacteric fruits as well as the presence of system 2 of ethylene production point to a ubiquitous role for ethylene in fruit ripening.
Postharvest Physiology of Tropical Fruit
Basic postharvest physiology of tropical fruit is similar to that of temperate fruit. The only clear physiological difference is that tropical fruit are chilling sensitive while most temperate fruit are chilling insensitive. Most of this knowledge was derived from work with banana, mango, pineapple and papaya. However, little work on chilling physiology has been reported in recent years. For other tropical fruit, the studies have emphasized handling and storage, less so physiology. Lack of physiological research will limit the expansion of tropical fruit in the world market. Respiration and ethylene production rates are largely known but there is a need for knowledge on sensitivity to ethylene is to improve postharvest handling and management of these fruit. Furthermore, individual tropical fruit species are unique and require detailed study. For example, durian fruit suffer from uneven ripening. Basic work on growth and development of durian led to the suggestion that the problem stemmed from the preharvest uneven development of the fruit itself. Mangosteen fruit are affected by husk hardening and a translucent pulp disorder. Studies on these two problems led to new knowledge on the biochemistry of fruit texture. INTRODUCTION There are numerous species of tropical fruit, but information on their physiological behavior after harvest is quite limited, except for banana, mango and pineapple. This paper reviews briefly the general postharvest physiology, and progress in chilling injury research. It describes in more detail the postharvest physiology of the peel and of individual fruit that behave atypically.
Internal atmosphere of fruits: Role and significance in ripening and storability
Postharvest Ripening Physiology of Crops. Series: Innovation in Postharvest Technology. Sunil Pareek (Ed.), 2016
Ripening, storability, quality attributes, and postharvest losses in fruits are interlinked with one another. The postharvest life of a fruit is primarily determined by various physiological processes and associated metabolic changes occurring in the fruit. The role of the external atmosphere in reg¬ulating the above processes and changes is relatively better understood. However, little is known about the overall internal atmosphere of the fruit and how it influences different aspects of ripening and storability. This chapter looks into this emerging area: the basic and applied importance of the internal atmosphere to postharvest physiology and food science and technology. There are various gases and volatiles that make the internal atmosphere of fruits. Their production and diffusion across the fruit tissues are governed by many factors. Differences in morphological, anatomical, and microstructural features of fruits are now assuming greater impor¬tance, as they are involved in determining the internal environment of fruits. As a consequence, there exists variability in the internal atmosphere of fruits, which is evident not only at the level of different species, but also within species. Differences in ripening behavior of different fruits under plant-attached and -detached conditions are also expected in view of the above. The involvement of some of gases (ethylene, oxygen, and carbon dioxide) and volatiles (ethanol, acetaldehyde, water vapors and water sta¬tus, salicylic acid and methyl salicylate, jasmonic acid and jasmonates, and nitric oxide) in the regulation of ripening-related changes, including flavor and aroma, is described and discussed at the individual as well as at the interactive level (especially with ethylene). Some examples are presented wherein endogenous and exogenous volatiles exhibit a positive effect on the fruit’s storability, quality, and tolerance to biotic and abiotic stresses. Lastly, a few researchable issues are suggested. The outcome from this area can supplement the existing storage technologies, and this will be highly desirable in achieving a more effective and holistic way of the postharvest management of perishable commodities.
Development and ripening of yellow passion fruit
Journal of Horticultural Science, 1995
Yellow passion fruit (Passiflora edulis f,flavicarpa Deg.) showed a single sigmoid curve of fruit growth and reached maximum size 21 d after flowering. Fruit fresh and dry weight increased until 50 and 70 d after flowering, respectively. Growth in the first 21 d was due mainly to rind growth, and subsequent growth was due primarily to growth of pulp (arils and seeds). Accumulation of soluble solids and acids peaked 63 dafter flowering, followed by a decline of the former coinciding with the initiation of the climacteric rise of respiration and ethylene production. Ethephon applied to harvested fruit 40, 50, 60 and 70 d old advanced the initiation of the climacteric compared with untreated fruit. Since detached 40 d old fruit did not ripen without ethephon treatment, physiological maturity of yellow passion fruit is reached some time after 40 d.
Mechanisms of Fruit Ripening: Retrospect and Prospects
IV International Conference on Managing Quality in Chains - The Integrated View on Fruits and Vegetables Quality, 2006
This paper aims at giving an overview of the progress made during the last decades on the mechanisms of fruit ripening and to present the most recent trends and prospects for the future. Important steps forward will be presented (respiratory climacteric, ethylene biosynthesis and action, isolation of genes involved in the ripening process, biotechnological control of fruit ripening....) by showing how the judicious exploitation of the data published previously, the strategies, methodologies and plant material adopted have been crucial for the advancement of knowledge. Opportunities of co-operation between geneticists and post-harvest physiologists as well as new possibilities offered by genomics, proteomics and metabolomics for the understanding of the fruit ripening process and the development of sensory quality will be developed.
Role of internal atmosphere on fruit ripening and storability—a review
Concentrations of different gases and volatiles present or produced inside a fruit are determined by the permeability of the fruit tissue to these compounds. Primarily, surface morphology and anatomical features of a given fruit determine the degree of permeance across the fruit. Species and varietal variability in surface characteristics and anatomical features therefore influence not only the diffusibility of gases and volatiles across the fruits but also the activity and response of various metabolic and physiological reactions/processes regulated by these compounds. Besides the well-known role of ethylene, gases and volatiles; O2, CO2, ethanol, acetaldehyde, water vapours, methyl salicylate, methyl jasmonate and nitric oxide (NO) have the potential to regulate the process of ripening individually and also in various interactive ways. Differences in the prevailing internal atmosphere of the fruits may therefore be considered as one of the causes behind the existing varietal variability of fruits in terms of rate of ripening, qualitative changes, firmness, shelf-life, ideal storage requirement, extent of tolerance towards reduced O2 and/or elevated CO2, transpirational loss and susceptibility to various physiological disorders. In this way, internal atmosphere of a fruit (in terms of different gases and volatiles) plays a critical regulatory role in the process of fruit ripening. So, better and holistic understanding of this internal atmosphere along with its exact regulatory role on various aspects of fruit ripening will facilitate the development of more meaningful, refined and effective approaches in postharvest management of fruits. Its applicability, specially for the climacteric fruits, at various stages of the supply chain from growers to consumers would assist in reducing postharvest losses not only in quantity but also in quality.
A Firm Focus on Tropical Fruit Ripening
Acta horticulturae, 2011
Development of fruits, including tropical fruits, follows several patterns. Mature fruit then undergo ripening which is a coordinated process typically involving changes in pigmentation, flavour, respiration, surface waxes and texture. The latter, ripening-related fruit softening, is reviewed in depth. Changes in the cell walls of fruits underpin this softening but it is important to appreciate these biochemical changes may not occur uniformly throughout the wall but in discrete zones. To understand the basis of this phenomenon, studies have either examined modifications in the polysaccharides that comprise the cell wall, i.e. the substrates, or the enzymes that catalyse such changes, in either case looking for correlations between these and softening. Molecular biological approaches have allowed a more detailed understanding of how such enzymes are regulated but more importantly using genetic engineering techniques it has been possible to silence or overexpress specific genes and more directly test the role of such proteins in fruit softening. Using the tomato model system the roles of potential mediators of fruit softening are examined; endo-β-1,4-glucanase, pectin methylesterase, polygalacturonase, pectate lyase, xyloglucan endotransglucosylase/hydrolase, endo-β-1,4-mannanase, βgalactosidase, α-arabinosidase, expansins and hydroxyl radicals. A similar review is made of ripening-related softening in the major tropical fruits, avocado, banana, mango and papaya. In all cases, both pectins and hemicelluloses are targeted, often using different enzymes. With such diversity of fruit development, it is not that surprising diverse mechanisms of softening come into play.
Fruits, 2005
A recent laboratory study demonstrated a negative correlation between the ethylene production of fruit during ripening and the length of their commercial life. The aim of our work was to determine whether there is a putative relationship between ethylene production of fruit during ripening and the length of the growth period before ripening. A positive answer would make this an important parameter for early selection in breeding programs. Materials and Methods. Four banana varieties representing a broad range of growth period lengths were studied. Ethylene biosynthesis was examined through ethylene production and content in free 1-aminocyclopropane-1-carboxylic acid (ACC)-the immediate precursor of the hormone-during fruit development and ripening. Fruit ripening was totally achieved on the plant. Results. Ethylene production started to be detected at the breaker stage. It peaked at the "fully dark-yellow-extremities included" stage for all varieties. Two varieties, i.e., Sowmuk and IDN 110, presented the highest production levels [(26 and 19) µL ethylene·h -1 ·kg -1 of fresh weight at peak, respectively). Galéo and Grande Naine had lower ethylene yields. The two most productive varieties also presented a drastic increase in free ACC at ripening onset. Conclusion. There is no relationship between ethylene production of bananas ripened on the plant and the length of the fruit growth period prior to ripening onset.
Pre- and Post-Harvest Management of Fruit Quality, Ripening and Senescence
Acta horticulturae, 2010
By the regulation of fruit ripening we ensure consumers have a year-round supply of fruit with acceptable eating quality and health promoting components. Fruit ripening is a highly regulated process with coordinated genetic and metabolic events, leading to essential changes in gene expression, physiology, biochemistry and anatomy. These complex regulatory events transform a physiologically mature but inedible fruit into an edible, tasty product. Molecular and genetic analysis of fruit development and especially of ripening, has resulted in confirmed gains in knowledge about ethylene biosynthesis and responses, cell wall metabolism and environmental factors. Innovations in CA technology like dynamic controlled atmospheres (DCA) and/or the use of the chemical ethylene inhibitor (1-MCP) are new tools for the enhancement and preservation of quality and health promoting components in climacteric fruit. DCA, with non destructive monitoring systems based either on ethanol concentrations or chlorophyll fluorescence allows the use of oxygen atmospheres during storage that are close to the lowest tolerance limits for fruit without inducing excessive anaerobic metabolism. In contrast to other available technologies, 1-MCP has the potential to control ethylene action by blocking the ethylene receptors and thereby maintaining fruit quality, and avoiding specific storage disorders not only in storage but also during marketing and shelf-life. Postharvest physiological disorders may result from oxidative stress influencing fruit physiology during fruit maturation and ripening when active oxygen species exceed the capacity of an organism to maintain redox homeostasis and exhaust the internal defence systems. Many postharvest researchers are involved in evaluating antioxidant activities as affected by cultivar, production practices and postharvest handling procedures. Sensory investigations and consumer expectation surveys have confirmed that the aroma, firmness, crispiness and juiciness are the most relevant sensory traits. Ripening regulation by modern storage technology shows great benefits in terms of texture, total soluble solids (TSS) and acidity but often hampers aroma formation mainly depending on the at-harvest ripening stage of the fruit. In the future, postharvest researchers will be challenged to meet consumer requirements with fruit that is well flavoured and nutritious.