Browsing by Author "Elmi, Fardusa"
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Item Open Access Continuous Exposure to Ethylene Differentially Affects Senescence in Receptacle and Achene Tissues in Strawberry Fruit(Cranfield University, 2020-02-20 13:41) Tosetti, Roberta; Elmi, Fardusa; Terry, Leon; Cools, Katherine; Pradas, InmaculadaStrawberry shelf life is limited, and little is known about the postharvest regulation of senescence in different fruit tissues. Strawberry is classified as a non-climacteric fruit, yet it is known that ethylene affects strawberry ripening. Here the effects of continuous exogenous ethylene (50 µL L-1) were investigated in cold stored strawberry (5° C). The physiological and biochemical responses of ripe strawberry were evaluated across six days, together with hormonal profiles of the whole fruit and individual tissues (achenes and receptacle). Continuous exposure to ethylene induced as a first response an accumulation of abscisic acid (ABA) in the receptacle tissue, followed by an increase in CO2 production. Ethylene also elicited sucrose hydrolysis and malic acid catabolism, with the major effect seen after 4 days of ethylene exposure. Additionally, accumulation of phenolics (epicatechin and chlorogenic acid) were also observed in ethylene treated strawberry. Achenes did not exhibit a response to ethylene, yet catabolism of both ABA and auxins increased by two thirds during air storage. In contrast, ethylene induced ABA accumulation in the receptacle tissue without ABA catabolism being affected. This hormonal disequilibrium in response to ethylene between the two tissues was maintained during storage, and therefore might be the precursor for the following biochemical variations reported during storage.Item Open Access Continuous exposure to ethylene differentially affects senescence in receptacle and achene tissues in strawberry fruit(Frontiers, 2020-03-12) Tosetti, Roberta; Elmi, Fardusa; Pradas, Inmaculada; Cools, Katherine; Terry, Leon A.Strawberry shelf life is limited, and little is known about the postharvest regulation of senescence in different fruit tissues. Strawberry is classified as a non-climacteric fruit, yet it is known that ethylene affects strawberry ripening. Here the effects of continuous exogenous ethylene (50 µl l−1) were investigated in cold stored strawberry (5°C). The physiological and biochemical responses of ripe strawberry were evaluated across 6 days, together with hormonal profiles of the whole fruit and individual tissues (achenes and receptacle). Continuous exposure to ethylene induced as a first response an accumulation of abscisic acid (ABA) in the receptacle tissue, followed by an increase in CO2 production. Ethylene also elicited sucrose hydrolysis and malic acid catabolism, with the major effect seen after 4 days of ethylene exposure. Additionally, accumulation of phenolics (epicatechin and chlorogenic acid) were also observed in ethylene treated strawberry. Achenes did not exhibit a response to ethylene, yet catabolism of both ABA and auxins increased by two thirds during air storage. In contrast, ethylene induced ABA accumulation in the receptacle tissue without ABA catabolism being affected. This hormonal disequilibrium in response to ethylene between the two tissues was maintained during storage, and therefore might be the precursor for the following biochemical variations reported during storageItem Open Access Elucidating ethylene-mediated physiology and biochemistry in selected climactic and non-climacteric fruits using e+® ethylene remover(Cranfield University, 2013-05) Elmi, Fardusa; Terry, Leon A.The presence of ethylene in a storage environment can undermine both quality and postharvest life of many fruits, often generating significant waste and associated economic losses. A demand for discovering alternative technologies capable of scavenging ethylene has led to the development of a new material, e+® Ethylene Remover, which has significant ethylene adsorption capacity. The material has been shown to remove ethylene to below physiologically active levels during fruit storage at 0-20 o C and consequently extend postharvest life for a variety of fresh produce types. Different formats incorporating e+® Ethylene Remover have been developed. Successful application of e+® Ethylene Remover in laboratory settings has created opportunities to test new formats of the product. To this end, work was conducted herein to attest whether e+® Ethylene Remover, which has been shown to maintain avocado (Persea americana cv. Hass) firmness in recent laboratory trials, could result in a meaningful extension of storage life in a commercial setting. It was shown that e+® Ethylene Remover coated sheets were a highly efficacious format for suppressing ethylene and extending storage life of imported avocado and pluot plums in a series of commercial trials. Moreover, the potency of the e+® Ethylene Remover treatment in retarding ethylene induced ripening was significantly enhanced when avocados were treated during the early stages of ripening. After a storage period of up to 31 days (5-6 o C), avocado fruits which had received an early treatment at source and then treated again in the laboratory were significantly more firm and greener compared to fruits treated following 5 weeks of transit alone . Strawberry is regarded as non-climacteric fruit; nevertheless, exogenous ethylene can negatively influence postharvest life. The low ethylene produced by non-climacteric fruits has been generally ignored and research reporting on the involvement of ethylene in these fruits is typically devoid in the literature. To this end, application of a highly sensitive laser based photoacoustic ethylene detector has revealed a possible role of ethylene in determining the postharvest life of strawberries. Moreover, fruit quality parameters including disease incidence, sugars, organic acids, phenolic compounds and plant phytohormones/metabolites were found to be profoundly affected by ethylene and likewise the removal of ethylene. Storage of strawberries in the presence of e+® Ethylene Remover was associated with lower disease incidence, significantly less red fruits and higher ascorbic acid content. In contrast, ethylene and 1-methylcyclopropene (1-MCP) treatments resulted in the higher postharvest disease. Ethylene-treated fruits were associated with lower level of sucrose and higher simple sugars (fructose and glucose) suggesting a role of ethylene in promoting the rate of senescence and concomitant reduced postharvest quality of strawberries. Changes in ABA, ABA metabolites and auxins within different tissues of ripe strawberry during storage were investigated. ABA was more abundant in the flesh than in the achenes, while auxins were undetectable in the flesh tissue. Auxins indole-3-acetic acid (IAA) and the conjugated form indole-3-acetylaspartic acid (IAAsp) were detected in high concentrations in the achenes and were affected by ethylene and storage length.