persimmon fruit. In previous studies, the action of ethylene may also affect the gene expression of cell wall degradation–related enzymes during persimmon fruit softening ( Wang et al., 2017 ; Zhu et al., 2012 ). Loss of astringency is another typical
Jingjing Kou, Zhihui Zhao, Wenjiang Wang, Chuangqi Wei, Junfeng Guan, and Christopher Ference
Shaolan Yang, Changjie Xu, Bo Zhang, Xian Li, and Kunsong Chen
et al., 2001 ), pear ( Hiwasa et al., 2003 ), litchi ( Wang et al., 2006a ), and banana ( Wang et al., 2006b ). Expression of ripening-related expansin was induced by ethylene and inhibited by 1-methylcyclopropene, a gaseous ethylene binding inhibitor
Xingbin Xie, Congbing Fang, and Yan Wang
during storage ( Charoenchongsuk et al., 2015 ). Ethylene is a ripening/senescence hormone and is also involved in chlorophyll degradation in fruit peel and plant leaves ( Amir-Shapira et al., 1987 ; Porat et al., 1999 ). 1-MCP is an ethylene action
Rongcai Yuan and David H. Carbaugh
first application ( Smock and Gross, 1947 ). On the contrary, application of ethephon, an ethylene-releasing compound, effectively promoted mature fruit abscission and ripening in apples ( Edgerton and Blanpied, 1970 ), oranges ( Yuan et al., 2002 ), and
Stanley J. Kays
While we tend to think of postharvest volatiles as nitrogen, oxygen, carbon dioxide and ethylene, harvested products are actually exposed to thousands of volatile compounds. These volatiles are derived from both organic and inorganic sources, evolving from storage room walls, insulation, wrapping materials, combusted products, plants, animals, and a myriad of other sources. Plants alone manufacture a diverse array of secondary metabolizes (estimated to be as many as 400,000) of which many display some degree of volatility. We tend to be cognizant of volatiles when they represent distinct odors. A number of volatiles, however, have significant biological activity, and under appropriate conditions may effect postharvest quality. An overview of biologically active volatile compounds and their relation to postharvest quality will be presented.
Dwight R. Tingley and Timothy A. Prince
A survey of 16 cut evergreen species found six clustered groupings of species based on ethylene production at 2 and 21C. Ethylene production (in nanoliters per kilogram of fresh weight per hour) at 21C ranged from 26 for Juniperus virginiana to 2800 for Sequoia sempervirens. Exposure to 0.1 or 1.0 ppm ethylene for 72 hours at 2C resulted in minor effects on two species, while significantly delaying senescence of Sequoia sempervirens. Silver thiosulfate (STS) pretreatment decreased or increased longevity of six species, but all effects were minor. Longevity of cut evergreens when held in preservative solution ranged from 14 days for Pinus sylvestris to 56 days for Chamaecyparis lawsoniana. Senescence symptoms observed were needle abscission, desiccation, and/or chlorosis.
Margrethe Serek, Edward C. Sisler, and Michael S. Reid
A 6-hour fumigation of flowering Begonia ×elatior hybrida Fotsch. `Najada' and `Rosa', B. ×tuberhybrida Voss. `Non-Stop', Kalanchoe blossfeldiana Poelln. `Tropicana', and Rosa hybrida L. `Victory Parade' plants with 1-MCP, (formerly designated as SIS-X), a gaseous nonreversible ethylene binding inhibitor, strongly inhibited exogenous ethylene effects such as bud and flower drop, leaf abscission, and accelerated flower senescence. The inhibitory effects of 1-MCP increased linearly with concentration, and at 20 nl·liter-1 this compound gave equal protection to that afforded by spraying the plants with a 0.5 STS mm solution. Chemical names used: 1-methylcyclopropene (1-MCP), silver thiosulfate (STS).
Bruno Defilippi*, Abhaya Dandekar, and Adel Kader
To understand the role of ethylene in overall flavor of apple fruits, ethylene production, and action were reduced using apple trees lines transformed for suppressing activity of ACC-synthase or ACC-oxidase enzymes, and 1-methylcyclopropene (1-MCP), an ethylene action inhibitor. A major reduction in ethylene biosynthesis and respiration rates was measured in fruits from these treatments. As expected, we found differential levels of dependence of flavor components on ethylene biosynthesis and action. Regarding aroma production, an ethyleneassociated event, headspace analysis showed a reduction in ester production in the ethylene-suppressed lines and in the apples treated with 1.0 μL·L-1 1-MCP for 20 hours at 20 °C. However, no major differences were observed in concentrations of alcohol and aldehyde volatiles. Other flavor metabolites that showed an ethylene-dependent pattern were organic acids and sugars. Malic acid degradation was significantly reduced under ethylene suppressed conditions, showing a recovery after exposing the fruit to ethylene. Sucrose and fructose concentrations were influenced by suppression or enhancement of ethylene. Total phenolics and individual phenolics showed an ethylene-dependent behavior only when ethylene biosynthesis was reduced, but not when ethylene action was affected. These results suggest that the regulatory mechanisms of aroma biosynthesis in apple are under partial ethylene regulation. Therefore, we are using the ethylene suppressed apple fruits study the channeling and regulation of other metabolic pathways that lead to the manifestation of a complex trait like fruit quality.
Marcio Eduardo Canto Pereira, Steven A. Sargent, Charles A. Sims, Donald J. Huber, Celso Luiz Moretti, and Jonathan H. Crane
, shelf life extension and year-round availability ( Crane et al., 2007 ). An extension of its shipping life would also represent an extension of marketing possibilities. The hormone ethylene (C 2 H 4 ) is essential for avocado ripening ( Zauberman et al
Steven A. Sargent and Jeffrey K. Brecht
Carambolas (Averrhoa carambola L., cv. Arkin) ware harvested at colorbreak (CB) and light green (LG) ripeness stages, commercially packed and cooled. The next day the fruit were treated as: Control (ungassed): CB, LG; Ethylene pretreatment (ETH) @100ppm: LC for 1, 2 or 3 days at 20°C or 25°. After pretreatment the fruit were stored at 5°. After 1, 2, 3, 4 weeks, 10 fruit from each treatment ware removed from storage and placed at 20°. Fruit color and decay were rated daily until 80% of the fruit in each treatment reached the yellow ripeness stage, at which time external color, total soluble solids (TSS), pH and total titratable acidity (TTA) were determined. Carambolas harvested at the LG stage can be ripened to good quality with ETH pretreatment. For two weeks storage at 5°, 2 days ETH are necessary at 20° or 25° to initiate ripening. For three weeks storage, 3 days ETH are required at 20°, and 2 or 3 days ETH are required at 25°. Fruit stored four weeks were of fair quality. LG with slower ripening initiation developed chilling injury during storage; the fastest initiation had the best color but the shortest marketing life. Fruit harvested CB had slightly higher TSS than ETH-treated LG but pH and TTA were similar.