Response of Developing Apple Fruits to Ethylene Treatment

Knee, M., Hatfield, S. G. S. and Bramlage, W. B. 1987. Responseof developing fruits to ethylene treatment.—J. exp. Bot.38: 972–979. Fruits of apple (Malus domestica Borkh. cv. Cox's Orange Pippin)were treated with various concentrations of ethylene usuallyfor 48 h to determine their response in relation to stage ofdevelopment. The main response recorded was the reduction byethylene of the delay in onset of rapid ethylene production(DEP) in individual fruits. Early in development low concentrationsof ethylene had little effect but DEP was progressively reducedby concentrations up to 10⁷ mm³ m^–3. As the fruit approachedthe natural onset of rapid ethylene synthesis concentrationsof 10² and 10³ mm³ m^–3 became increasingly effective.Increasing the duration of treatments with a fixed concentrationreduced DEP proportionately. Delay after harvest in applyinga 48 h treatment had little effect on the relation between DEPand concentration of ethylene applied. Although resistance todiffusion of gas in fruits increased during fruit developmentthis resistance was never large enough to affect the relationof concentration and response. Key words: ethylene, fruit ripening, Malus domestica     

Metabolism of 1-Aminocyclopropane-l-Carboxylic Acid during Apple Fruit Development

The metabolism of [U^–14C] 1-aminocyclopropane-1-carboxylicacid (ACC) supplied to whole fruits of apple (Malus domesticaBorkh., cv. Cox's Orange Pippin) was investigated. Radioactiveethylene was recovered in mercuric acetate traps and an acidicmetabolite was formed in proportions which varied little withthe absolute amount of substrate supplied. The amount of ACCusually supplied did not cause immediate, rapid ethylene productionby mature, pre-climacteric fruit but the onset of productionwas earlier than in untreated fruit. The radioactive acidic metabolite was purified by four chromatographicprocedures and activity was coincident with authentic 1-malonylamino)cyclopropane-1-carboxylic acid (MACC). The presence of thiscompound was confirmed by gas chromatography linked to massspectrometry. MACC was a major metabolite of [¹⁴C] ACC supplied to applesthroughout fruit development. The proportion converted to ethylenewas low but increased with endogenous ethylene production inthe final samples. MACC was shown to be a natural constituent of apple fruits andto accumulate to the amol kg^–1 level. Key words: 1-Aminocyclopropane-l-carboxylic acid, Ethylene, 1 (Malonylamino) cyclopropane-1-carboxylic acid, Malus domestica     

Results of a ground-water level and nitrogen fertilizer field experiment with apple trees on a marine clay soil

This paper summarizes and reviews some of the results of a 12-year experiment which was carried out in order to examine drainage requirements of apple trees on a newly reclaimed soil. The experiment involved production of Cox's Orange Pippin and Golden Delicious apples, grafted on M9 rootstock, that were planted on 11 different ground-water regime plots which were split into three nitrogen treatment sub-plots. It was found that there was a distinct variation in amounts of shoot growth, apple production nitrogen mineralization, and fruit quality on account of variations in the ground-water regime. No optimum ground-water regime could be established. This optimum may be quantified by using the capital budgeting decision procedure. The optimum nitrogen concentration in mid-shoot leaves, however, was found to be 2.3 and 2.4 percent of dry matter for Golden Delicious and Cox's Orange Pippin respectively. This report has been printed as a book with 266 pages, 96 figures, and 112 references. The book can be obtained from Ijsselmeerpolders Development Authority, P.O. Box 600, 8200 AP Lelystad, The Netherlands. Price of the book is D.Fl. 69,-and it includes postage.     

Carotenoids of Some Apples

Three varieties of crab apples and two varieties of eating appleshave been investigated for their carotenoid contents. ß-caroteneis not always the major carotenoid and epoxy-carotenoids arefound in fairly large amounts. There are relatively more carotenesthan xanthophylls in two of the crab apples while the reverseis observed in the eating apples studied. Cox's Orange Pippincontains 33 I.U. of vitamin A activity, Golden Delicious 3.6,while the crab apple Golden Hornet has 132 I.U. per gramme dryweight. Further, the peel has a greater concentration of carotenoidsthan the flesh except in the crab apple Pyrus baccata wherethe ratio is 1: 1     

Ovule and Embryo Sac Development in Malus pumila L. cv. Cox's Orange Pippin, from Dormancy to Blossom

Ovule and embryo sac development in the flowers of Cox's OrangePippin apple (Malus pumila L.) were studied from dormancy topetal fall using both scanning electron and light microscopy.The relative timing was established between these developmentsand the external development of the flower bud and flower. Malus pumila L. cv. Cox's Orange Pippin, apple, Cox, SEM, ovule development, anatomy, histology     

Ethylene-promoted conversion of 1-aminocyclopropane-1-carboxylic Acid to ethylene in peel of apple at various stages of fruit development

Internal ethylene concentration, ability to convert 1-amino-cyclopropane-1-carboxylic acid (ACC) to ethylene (ethylene-forming enzyme [EFE] activity) and ACC content in the peel of apples (Malus domestica Borkh., cv Golden Delicious) increased only slightly during fruit maturation on the tree. Treatment of immature apples with 100 microliters ethylene per liter for 24 hours increased EFE activity in the peel tissue, but did not induce an increase in ethylene production. This ability of apple peel tissue to respond to ethylene with elevated EFE activity increased exponentially during maturation on the tree. After harvest of mature preclimacteric apples previously treated with aminoethoxyvinyl-glycine, 0.05 microliter per liter ethylene did not immediately cause a rapid increase of development in EFE activity in peel tissue. However, 0.5 microliter per liter ethylene and higher concentrations did. The ethylene concentration for half-maximal promotion of EFE development was estimated to be approximately 0.9 microliter per liter. CO₂ partially inhibited the rapid increase of ethylene-promoted development of EFE activity. It is suggested that ethylene-promoted CO₂ production is involved in the regulation of autocatalytic ethylene production in apples.     

Effects of temperature and daminozide on the induction of ethylene synthesis in two varieties of apple

Factors affecting the induction of ethylene synthesis in apple were investigated through their effect on the delay in ethylene production (DEP) in single fruits after harvest. DEP in Cox apples was not affected by temperature from 1 to 25°C, but in Golden Delicious, DEP was shorter below 12°C and above 20°C. An orchard treatment with daminozide increased DEP in apples held below 15°C or treated with ethylene after harvest. Experiments in which the temperature was changed after ethylene treatment showed that ethylene was less active at 5°C than at 15°C but that response to it could be equally rapid. The results suggest that endogenous ethylene is not regulatory prior to the onset of rapid ethylene synthesis.     

Effect of orchard and postharvest application of daminozide on ethylene synthesis by apple fruit

The effects of daminozide (butanedioic acid-2,2-dimethylhydrazide) on ethylene synthesis by apple fruits were investigated. The objective was to determine the effects of postharvest applications as compared to the standard application of diaminozide in the orchard. Immersion in a solution containing 4.25 g L^?1 active ingredient for 5 min delayed the rise in ethylene production in individual “Cox” apples at 15°C by about 2 days, whereas orchard application of 0.85 g L^?1 caused delays of about 3 days. Both modes of application depressed the maximal rate of ethylene production attained by ripe apples by about 30%. Daminozide did not affect the stimulation of respiration by ethylene treatment of “Gloster” apples, but it delayed the increase in ethylene synthesis. Daminozide applied immediately after harvest delayed the rise in ethylene synthesis in “Golden Delicious” held at 15°C, but it was less effective when applied 48 h after harvest or when apples were held at 5°C. Exposure to 1–2 μl L^?1 ethylene for 48 h was less effective in promoting the rise in ethylene in daminozidetreated “Cox” and “Gloster” apples than in untreated fruit. High (100–1000 μl L^?1) concentrations of ethylene more or less overcame the daminozide effect. Apples absorbed about 40% of surface-applied [¹⁴C]daminozide in 48 h, but more than 90% of the radioactivity in the fruit was recovered from the peel and outer 1 cm of the cortex. Daminozide was partly converted to carbon dioxide and other metabolites.     

Stomatal and Chlorophyll Distribution of Cox's Orange Pippin Apple Flowers Relative to Other Cluster Parts

Surface area, chlorophyll concentration and stomatal size anddensity were measured for all green components of floral clusterson Cox's Orange Pippin apple trees to assess their relativepotential for photosynthesis. Before flower opening, sepalsand receptacles had chlorophyll concentrations similar to thosefound in the laminae of rosette leaves. But, whereas the concentrationin rosette leaves continued to increased until fruit set, thosein the sepals and receptacles decreased. Sepals had a greater mature stomatal density than leaf laminaeshortly after bud burst; although both densities increased,that on the laminae later exceeded that on sepals. Flowers contributed significantly to the green surface are (40%),chlorophyll content (30%) and mature stomatal number (25%) offloral clusters at the green cluster stage, but these contributionsthen decreased. Cox apple flowers appear to have the potentialfor contributing significantly to their carbohydrate requirementat a time when the rosette leaves are not thought to be exportersof photosynthate.Copyright 1993, 1999 Academic Press Malus pumila, apples flowers, chlorophyll, stomata, surface area, flower photosynthesis     

THE ROTTING OF APPLES BY GLOEOSPORIUM PERENNANS ZELLER & CHILDS

The extent of rotting of commercially stored Cox's Orange Pippin apples by Gloeosporium species has been severe in recent years. G. perennans has been found to be mainly responsible.
Tree infections of this fungus have usually been found to be prevalent in the orchards on farms where storage losses of fruit have occurred, and conidia of G. perennans have been found on cankers at all seasons during the year. Winter as well as summer pruning cuts have been found to become infected. Detached leaves of Cox's Orange Pippin have been successfully inoculated with G. perennans in the laboratory and the fungus has also been found on dead detached leaves in the orchard after picking time. Considerable variations have been found in the susceptibility to rotting of samples of different varieties of apple and samples of Cox's Orange Pippin apples from different orchards. Periodic loading of fruit with spores after picking has shown that resistance declines with length of storage. Wide variation in the time at which rotting commences in commercially stored samples has been observed. A series of inoculations on picked and unpicked immature fruit has shown that the apple loses its resistance to attack on picking. Lenticels which are impermeable to gaseous exchange have been shown to be resistant to penetration by the fungus. Temperature affects the development of lenticel rotting by G. perennans , infection being most rapid at temperatures of about 20°. Rotting can occur at 0° C.     

The Effect of Temperature on Growth and Mineral Nutrition of Fruits of Apple, with Special Reference to Calcium

Growth and mineral composition of fruits in potted trees were studied at two temperatures (19 and 24°C) in two experiments with Golden Delicious and one with Cox's Orange Pippin under a controlled environment. In Golden Delicious the high temperature promoted fruit growth markedly, but in Cox's Orange Pippin the stimulation was much less pronounced. The levels of K, N, Mg, and P (expressed as amounts per fruit) were increased at the higher temperature. This increase was almost completely the result of differences in fruit growth. With respect to Ca the high temperature reduced Ca influx in one Golden Delicious experiment and had hardly any effect in the other, but favoured influx in Cox's Orange Pippin. In one Golden Delicious experiment the temperature was raised 7 weeks after blossoming, which resulted in a temporary drop of Ca. When the same temperature change was applied 4 weeks earlier, Ca continued to increase. It is assumed that mineral influx occurs via the xylem during the first few weeks after fruit set and via the phloem throughout. The results are discussed in terms of differences in mobility in the phloem for the various minerals and of a shift in the ratio between xylem and phloem movement induced by differences in the growth rate of the fruits.     

An ethylene-related cDNA from ripening apples

We report the isolation of a ripening-related apple cDNA which is complementary to a mRNA which may be involved in ethylene production. Poly(A)⁺ RNA was extracted from cortical tissue of ripe apple fruit (Malus domestica Borkh cv. Golden Delicious) and a cDNA library constructed in the plasmid vector pSPORT. The library was screened with pTOM13, a tomato cDNA clone thought to code for ACC oxidase in that fruit. An apple cDNA clone (pAP4) was isolated and sequenced. The 1182 bp cDNA insert includes an open reading frame of 942 bp, and shows strong homology with reported tomato and avocado sequences, both at the nucleic acid and amino acid levels. The polypeptide has a calculated molecular mass of 35.4 kDa and a calculated pI of 5.15. In apple cortical tissue, expression of pAP4-complementary RNA increased with ethylene production by the fruit during ripening. Expression was also enhanced in both ethylene-treated and wounded fruit.     

Inhibition by polyamines of macromolecular synthesis and its implication for ethylene production and senescence processes

Applied diamines and polyamines inhibited the incorporation of radioactively labeled leucine and uridine into trichloroacetic acid-insoluble material in apple (Malus domestica Borkh, cv Golden Delicious) fruit tissue. The inhibitory effect was in general more pronounced with the higher molecular weight amines. Putrescine at 5 millimolar inhibited leucine incorporation by 37% and uridine by 44%. Spermidine and spermine at the same concentration inhibited uridine incorporation by 60%. The polyamines at concentrations between 0.1 and 1.0 millimolar inhibited leucine incorporation by 55 to 90%. The inhibitory effect of 0.1 to 10 millimolar polyamines on dark- and wound-induced senescence or ethylene production, is discussed in the light of interference with macromolecular synthesis.     

Electron-energy-loss spectroscopic imaging of calcium and nitrogen in the cell walls of apple fruits

Changes in texture are an integral part of ripening in most fleshy fruits and these changes are thought to be determined, primarily, by alterations in cell wall structure. Electron energy loss spectroscopy (EELS) imaging was used to obtain quantitative information on the levels of calcium and nitrogen in the cell walls of apple (Malus domestica Borkh. cv. Cox's Orange Pippin) fruits. Samples of fruit cortex were prepared for EELS by high-pressure freezing and molecular distillation drying to minimize loss and redistribution of soluble cell wall components such as calcium. The EELS imaging successfully resolved calcium and nitrogen levels in the middle lamella and primary cell wall. When the elemental compositions of the cell walls of Cox's apples from two sites in the UK were compared at harvest or after 6 months storage, the orchard which always produced consistently firmer fruit had significantly lower levels of cell wall calcium and higher levels of cell wall nitrogen. This result was unexpected since firm texture in apples and other fruits has been commonly associated with elevated levels of fruit calcium. The nitrogen-rich material in the sections used for EELS was insoluble in acidified methanol, indicating that it represented a high-molecular-weight component in the cell wall. Furthermore, total tissue hydroxyproline levels were greatest in material with elevated cell wall nitrogen, suggesting enhanced levels of wall structural proteins in the tissue. These data indicate a correlation between increased amounts of cell wall nitrogen and firm fruit texture. The possible role of cell wall proteins in determining the textural properties of fruit tissue is discussed. Received: 19 November 1998 / Accepted: 28 January 1999     

A role for jasmonates in climacteric fruit ripening

Jasmonates are a class of oxylipins that induce a wide variety of higher-plant responses. To determine if jasmonates play a role in the regulation of climacteric fruit ripening, the effects of exogenous jasmonates on ethylene biosynthesis and color, as well as the endogenous concentrations of jasmonates were determined during the onset of ripening of apple (Malus domestica Borkh. cv. Golden Delicious) and tomato (Lycopersicon esculentum Mill. cv. Cobra) fruit. Transient (12 h) treatment of pre-climacteric fruit discs with exogenous jasmonates at low concentration (1 or 10 μM) promoted ethylene biosynthesis and color change in a concentration-dependent fashion. Activities of both 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase and ACC synthase were stimulated by jasmonate treatments in this concentration range. The endogenous concentration of jasmonates increased transiently prior to the climacteric increase in ethylene biosynthesis during the onset of ripening of both apple and tomato fruit. The onset of tomato fruit ripening was also preceded by an increase in the percentage of the cis-isomer of jasmonic acid. Inhibition of ethylene action by diazocyclopentadiene negated the jasmonate-induced stimulation of ethylene biosynthesis, indicating jasmonates act at least in part via ethylene action. These results suggest jasmonates may play a role together with ethylene in regulating the early steps of climacteric fruit ripening. Received: 14 August 1997 / Accepted: 4 October 1997     

Changes in mRNA and Protein during Ripening in Apple Fruit (Malus domestica Borkh. cv Golden Delicious)

Poly(A)⁺ RNA was extracted from cortical tissue of apple fruit (Malus domestica Borkh. cv Golden Delicious), and in vitro translation products were analyzed by two-dimensional gel electrophoresis. As fruit internal ethylene concentration increased from a basal level of 0.0 to 0.1 microliter per liter to 1 to 5 microliters/liter, substantial changes in the pattern of in vitro translation products were observed. More subtle changes were observed as fruit continued to ripen and internal ethylene concentration increased to 80 to 100 microliters/liter. Overall, the levels of at least six mRNAs were found to increase, while one mRNA decreased. Analysis of proteins extracted from ripening fruit indicated that the level of at least three proteins increased with ripening.     

Xylem Development in the Gynoecium of the Apple (Malm pumila L.) Cv. Cox's Orange Pippin K. A. D. *J. COSTA TURA{dagger}

Lignification of the xylem within the carpellary bundles ofapple flowers spreads acropetally from a point 900–1400µm below the base of the locules. At the same time, anotherwave of lignification spreads basipetally from a point justbelow the stigma. The acropetal spread at first progresses morequickly, but at later stages the number of lignified xylem elementsjust below the stigma increases rapidly, reaching a peak justas the flower opens. This increase is very localized and thenumber declines greatly within only 25 % of the stylar distancebelow the stigma. Lignification of the xylem in the bundlesserving other flower parts precedes that serving the gynoecium,and spreads basipetally from a point above the base of the locules Malus pumila, L., anatomy, apple, carpel, Cox's Orange Pippin, development, flower, gynoecium, pedicel, pistil, stigma, style, vasculature, xylem regenreation     

Xylem Development in the Gynoecium of the Apple (Malus pumila L.) Cv, Cox's Orange Pippin

Lignification of the xylem within the carpellary bundles ofapple flowers spreads acropetally from a point 900–1400µm below the base of the locules. At the same time, anotherwave of lignification spreads basipetally from a point justbelow the stigma. The acropetal spread at first progresses morequickly, but at later stages the number of lignified xylem elementsjust below the stigma increases rapidly, reaching a peak justas the flower opens. This increase is very localized and thenumber declines greatly within only 25% of the stylar distancebelow the stigma. Lignification of the xylem in the bundlesserving other flower parts precedes that serving the gynoecium,and spreads basipetally from a point above the base of the locules. Malus pumila L, anatomy, apple, carpel, Cox's Orange Pippin, development, flower, gynoecium, pedicel, pistil, stigma, style, vasculature, xylem     

Demography and mass-rearing of Carposina sasakii Matsumura (Lepidoptera: Carposinidae) reared on Golden Delicious and Red Fuji apples in the laboratory

Carposina sasakii Matsumura (Lepidoptera: Carposinidae), is one of the most serious fruit-boring pests in over ten species of fruit trees, and is especially damaging apples in the northern of China. The application of new planting systems, i.e., high-density and dwarfing rootstock orchard systems with mixed apple varieties, makes it important to study the fitness of C. sasakii on these apple varieties to gain fundamental knowledge for use in pest management involving this insect. In this study, life table data of C. sasakii were collected using Golden Delicious and Red Fuji apples as hosts. The egg-larva duration of male C. sasakii reared on Golden Delicious apples (22.81 d) was significantly shorter than that reared on Red Fuji apples (24.27 d). The egg-larva mortality in Golden Delicious apples (59.00%) was lower than that in Red Fuji apples (72.49%). The mortality of the pupal stage, however, was higher in Golden Delicious (10.51%) than in Red Fuji (0%). The total oviposition period (TPOP) on Golden Delicious apples (32.94 d) was significantly shorter than in individuals reared on Red Fuji apples (34.19 d). The intrinsic rate of increase (r = 0.0581 d⁻¹), net reproductive rate (R₀ = 7.57 offspring), and finite rate of increase (λ = 1.0598 d⁻¹) were all higher on Golden Delicious than those on Red Fuji. When the net reproductive rate (R₀) was used, the harvest rate of pupae was higher (0.8678) when reared on Golden Delicious apples than when reared on Red Fuji apples (0.8398). When a large cohort size (n = 200) was used for effective bootstrap sample, the P_E values for C. sasakii reared on Golden Delicious apples and Red Fuji apples were both almost equal to 1. For C. sasakii culturing purposes, Golden Delicious apples would be more productive than Red Fuji.